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2021 Volume 32 Issue 3
2021, 32(3): 949-953
doi: 10.1016/j.cclet.2020.08.010
Abstract:
With excellent biocompatibility and biodegradability, natural polysaccharides and their derivatives have exhibited great potential in constructing drug delivery vehicles for tissue engineering and therapeutics. Cucurbit[n]uril (CB[n])-mediated reversible crosslinking of polysaccharides possess intrinsic stimuli-responsiveness towards competitive guests and have been extensively investigated to fabricate various particles and hydrogels for multiple stimuli-responsive drug release by incorporation with other stimuli including photo, redox, and enzyme. Through host-guest interactions between CB[6] and aliphatic diamines, functional tags covalently connected with CB[6] can be readily anchored into polysaccharide-based hydrogels, realizing multiple functionalization. The rheological property and drug release profile of polysaccharide-based supramolecular hydrogels can be facilely tuned through CB[8]-mediated dynamic homo or hetero crosslinking of polysaccharides and/or other polymers. In this review, we introduce and summarize recent progress regarding polysaccharide-based supramolecular drug delivery systems mediated via host-guest interactions of CB[6] and CB[8], covering both bulk hydrogels and particular systems. At the end, possible utilization of CB[7]-based host-guest interactions in constructing polysaccharide-based drug delivery systems and future perspectives of this research direction are also discussed.
With excellent biocompatibility and biodegradability, natural polysaccharides and their derivatives have exhibited great potential in constructing drug delivery vehicles for tissue engineering and therapeutics. Cucurbit[n]uril (CB[n])-mediated reversible crosslinking of polysaccharides possess intrinsic stimuli-responsiveness towards competitive guests and have been extensively investigated to fabricate various particles and hydrogels for multiple stimuli-responsive drug release by incorporation with other stimuli including photo, redox, and enzyme. Through host-guest interactions between CB[6] and aliphatic diamines, functional tags covalently connected with CB[6] can be readily anchored into polysaccharide-based hydrogels, realizing multiple functionalization. The rheological property and drug release profile of polysaccharide-based supramolecular hydrogels can be facilely tuned through CB[8]-mediated dynamic homo or hetero crosslinking of polysaccharides and/or other polymers. In this review, we introduce and summarize recent progress regarding polysaccharide-based supramolecular drug delivery systems mediated via host-guest interactions of CB[6] and CB[8], covering both bulk hydrogels and particular systems. At the end, possible utilization of CB[7]-based host-guest interactions in constructing polysaccharide-based drug delivery systems and future perspectives of this research direction are also discussed.
2021, 32(3): 954-962
doi: 10.1016/j.cclet.2020.08.012
Abstract:
Conia-ene reactions, as a type of ene reactions, have not become a remarkable focus until the beginning of 21st century, when Lewis acids served as powerful catalysts and found an increasingly broad utilization in this field. Consequently, the catalytic Conia-ene reactions have gained great significance in synthetic chemistry due to their high efficiency and atom economy on the construction of valuable cyclic molecules. During the past two decades, the rapid development of transition-metal catalysis and organocatalysis has imposed a profound impact on the exploration of asymmetric Conia-ene reactions. As a result, several strategies have been developed and applied successfully. Organized on the basis of the catalytic system, this review comprehensively presents a summary of recent progress achieved in this emerging domain, aimed at highlighting the reactions' features, practicalities, and the mechanistic rationale is presented where possible.
Conia-ene reactions, as a type of ene reactions, have not become a remarkable focus until the beginning of 21st century, when Lewis acids served as powerful catalysts and found an increasingly broad utilization in this field. Consequently, the catalytic Conia-ene reactions have gained great significance in synthetic chemistry due to their high efficiency and atom economy on the construction of valuable cyclic molecules. During the past two decades, the rapid development of transition-metal catalysis and organocatalysis has imposed a profound impact on the exploration of asymmetric Conia-ene reactions. As a result, several strategies have been developed and applied successfully. Organized on the basis of the catalytic system, this review comprehensively presents a summary of recent progress achieved in this emerging domain, aimed at highlighting the reactions' features, practicalities, and the mechanistic rationale is presented where possible.
2021, 32(3): 963-972
doi: 10.1016/j.cclet.2020.08.011
Abstract:
There is an increasing demand of using the low-cost and sustainable cobalt to replace its noble congeners (rhodium and iridium) as reflected by the recent upsurge of cobalt catalysis in the diverse organic transformations. Since all the redox reactivity of cobalt catalysis highly relies on the capability of the interconversion between their oxidation states (most frequently +1, +2 and +3), electrochemistry perfectly meets such a requirement owing to its outstanding performance in the redox manipulation. In this review, we highlight the recent advances in the merger of cobalt catalysis and electrochemistry in organic synthesis.
There is an increasing demand of using the low-cost and sustainable cobalt to replace its noble congeners (rhodium and iridium) as reflected by the recent upsurge of cobalt catalysis in the diverse organic transformations. Since all the redox reactivity of cobalt catalysis highly relies on the capability of the interconversion between their oxidation states (most frequently +1, +2 and +3), electrochemistry perfectly meets such a requirement owing to its outstanding performance in the redox manipulation. In this review, we highlight the recent advances in the merger of cobalt catalysis and electrochemistry in organic synthesis.
2021, 32(3): 973-982
doi: 10.1016/j.cclet.2020.09.007
Abstract:
Lithium-ion batteries (LIBs) have evolved into the mainstream power source of energy storage equipment by reason of their advantages such as high energy density, high power, long cycle life and less pollution. With the expansion of their applications in deep-sea exploration, aerospace and military equipment, special working conditions have placed higher demands on the low-temperature performance of LIBs. However, at low temperatures, the severe polarization and inferior electrochemical activity of electrode materials cause the acute capacity fading upon cycling, which greatly hindered the further development of LIBs. In this review, we summarize the recent important progress of LIBs in low-temperature operations and introduce the key methods and the related action mechanisms for enhancing the capacity of the various cathode and anode materials. It aims to promote the development of high-performance electrode materials and broaden the application range of LIBs.
Lithium-ion batteries (LIBs) have evolved into the mainstream power source of energy storage equipment by reason of their advantages such as high energy density, high power, long cycle life and less pollution. With the expansion of their applications in deep-sea exploration, aerospace and military equipment, special working conditions have placed higher demands on the low-temperature performance of LIBs. However, at low temperatures, the severe polarization and inferior electrochemical activity of electrode materials cause the acute capacity fading upon cycling, which greatly hindered the further development of LIBs. In this review, we summarize the recent important progress of LIBs in low-temperature operations and introduce the key methods and the related action mechanisms for enhancing the capacity of the various cathode and anode materials. It aims to promote the development of high-performance electrode materials and broaden the application range of LIBs.
2021, 32(3): 983-989
doi: 10.1016/j.cclet.2020.09.018
Abstract:
The intrinsic liquid interface of Na-K alloy allays concerns about dendrite growth on metal anodes that are thermodynamically within the room temperature (20–22 ℃). Nevertheless, it hinders the formation of a stable electrode structure due to the inferior wettability induced by considerable liquid tension. In addition, the dominant ionic carrier in the Na-K alloy is subject to multiple factors, which is not conducive to customized battery design. This review, based on recently reported frontier achievements on Na-K liquid anodes, summarizes practical strategies for promoting the wettability by high-temperature induction, capillary effect, vacuum infiltration, and solid interface protection. Furthermore, four selection mechanisms of the dominant ionic carrier are presented: (1) ion property dominated, (2) cathode dominated, (3) separator dominated, and (4) solid electrolyte interface dominated. Notably, initial electrolytes in energy storage systems have been unable to play a decisive role in ionic selection. Utilizing a superior wettability strategy and simultaneously identifying the dominant ionic carrier can facilitate the tailored application of dendrite-free Na-K liquid anodes.
The intrinsic liquid interface of Na-K alloy allays concerns about dendrite growth on metal anodes that are thermodynamically within the room temperature (20–22 ℃). Nevertheless, it hinders the formation of a stable electrode structure due to the inferior wettability induced by considerable liquid tension. In addition, the dominant ionic carrier in the Na-K alloy is subject to multiple factors, which is not conducive to customized battery design. This review, based on recently reported frontier achievements on Na-K liquid anodes, summarizes practical strategies for promoting the wettability by high-temperature induction, capillary effect, vacuum infiltration, and solid interface protection. Furthermore, four selection mechanisms of the dominant ionic carrier are presented: (1) ion property dominated, (2) cathode dominated, (3) separator dominated, and (4) solid electrolyte interface dominated. Notably, initial electrolytes in energy storage systems have been unable to play a decisive role in ionic selection. Utilizing a superior wettability strategy and simultaneously identifying the dominant ionic carrier can facilitate the tailored application of dendrite-free Na-K liquid anodes.
2021, 32(3): 990-998
doi: 10.1016/j.cclet.2020.08.048
Abstract:
As natural blood components, erythrocytes were good candidates for being used as drug delivery systems to improve the pharmacokinetics, biocompatibility and many other aspects of different drugs. The advantages brought by erythrocytes making erythrocyte-derived drug delivery systems, also known as erythrocyte carriers, suitable for various anti-cancer agents, especially newly invented agents like nanoparticles, which were characterized by their undesired systematic toxicity, anaphylactic reactions and poor biocompatibility. Current researches on erythrocyte carriers in cancer therapy showed inspiring results in four major aspects: cancer enzyme therapy, delivering chemotherapeutic agents, combining with nanoparticles, and several other anti-cancer agents for gene or immune therapy. This novel delivering system was now undergoing the translation process from laboratory to clinical practice. Erythrocyte carriers for cancer enzyme therapy have entered the stage of clinical trial and have showed promising outcomes, and others were still at pre-clinical stage. In summary, erythrocyte-derived drug delivery system might play an indispensable role in the management of cancer in the future.
As natural blood components, erythrocytes were good candidates for being used as drug delivery systems to improve the pharmacokinetics, biocompatibility and many other aspects of different drugs. The advantages brought by erythrocytes making erythrocyte-derived drug delivery systems, also known as erythrocyte carriers, suitable for various anti-cancer agents, especially newly invented agents like nanoparticles, which were characterized by their undesired systematic toxicity, anaphylactic reactions and poor biocompatibility. Current researches on erythrocyte carriers in cancer therapy showed inspiring results in four major aspects: cancer enzyme therapy, delivering chemotherapeutic agents, combining with nanoparticles, and several other anti-cancer agents for gene or immune therapy. This novel delivering system was now undergoing the translation process from laboratory to clinical practice. Erythrocyte carriers for cancer enzyme therapy have entered the stage of clinical trial and have showed promising outcomes, and others were still at pre-clinical stage. In summary, erythrocyte-derived drug delivery system might play an indispensable role in the management of cancer in the future.
2021, 32(3): 999-1009
doi: 10.1016/j.cclet.2020.10.005
Abstract:
Flexible rechargeable Zn-air batteries are considered as one of the most promising battery systems to drive flexible and wearable electronic devices owing to their high safety, high gravimetric energy density, low self-discharge and low cost. One of the key challenges is to develop air electrodes with high performance and high mechanical flexibility. This minireview discusses the recent progress in the design and fabrication of flexible air electrodes. It focuses on the latest innovations in bifunctional oxygen reduction reaction and oxygen evolution reaction electrocatalysts, mainly including carbon-based materials (e.g., heteroatom-doped carbon, metal-nitrogen moieties doped carbon), metal oxides (e.g., spinel oxides, perovskite oxides) and their composites. It aims to provide an insight into the structure-property relationship of bifunctional catalysts. We also discuss the challenges and future perspectives.
Flexible rechargeable Zn-air batteries are considered as one of the most promising battery systems to drive flexible and wearable electronic devices owing to their high safety, high gravimetric energy density, low self-discharge and low cost. One of the key challenges is to develop air electrodes with high performance and high mechanical flexibility. This minireview discusses the recent progress in the design and fabrication of flexible air electrodes. It focuses on the latest innovations in bifunctional oxygen reduction reaction and oxygen evolution reaction electrocatalysts, mainly including carbon-based materials (e.g., heteroatom-doped carbon, metal-nitrogen moieties doped carbon), metal oxides (e.g., spinel oxides, perovskite oxides) and their composites. It aims to provide an insight into the structure-property relationship of bifunctional catalysts. We also discuss the challenges and future perspectives.
2021, 32(3): 1010-1016
doi: 10.1016/j.cclet.2020.09.010
Abstract:
As a new treatment technique, photothermal therapy (PTT) has aroused worldwide attention in cancer treatment, mainly due to its excellent absorption ability, easy regulation, and biodegradability. Photothermal conversion materials with enhanced permeability and retention effect can be targeted easily to tumor tissue. They can accumulate efficiently to tumor tissues and allow normal tissues and organs not to be affected by temperature, thus significantly helping to reduce the systemic toxicity and improve the antitumor effect. However, PTT alone often suffers from therapeutic resistance and reduced therapeutic efficacy, due to photothermal nanomaterial-mediated fundamental cellular defense mechanism of heat shock response, which could be inhibited by small interfering RNA (siRNA). Nevertheless, photothermal conversion materials as an excellent siRNA delivery carrier may considerably enhance the delivery efficiency of siRNA. Therefore, photothermal and RNA interfering (RNAi) synergistic therapy has recently aroused extensive attention in tumor treatment. In this review, we mainly summarize the recent advances of photothermal and RNAi synergistic therapy, including some synergistic therapeutic nanoplatforms of inorganic and organic photothermal materials and other combined therapies such as combining with small molecular antitumor agents or PDT/imaging. The combination of various treatment techniques may considerably improve the synergistic therapeutic effect of PTT and RNAi in the treatment of cancers.
As a new treatment technique, photothermal therapy (PTT) has aroused worldwide attention in cancer treatment, mainly due to its excellent absorption ability, easy regulation, and biodegradability. Photothermal conversion materials with enhanced permeability and retention effect can be targeted easily to tumor tissue. They can accumulate efficiently to tumor tissues and allow normal tissues and organs not to be affected by temperature, thus significantly helping to reduce the systemic toxicity and improve the antitumor effect. However, PTT alone often suffers from therapeutic resistance and reduced therapeutic efficacy, due to photothermal nanomaterial-mediated fundamental cellular defense mechanism of heat shock response, which could be inhibited by small interfering RNA (siRNA). Nevertheless, photothermal conversion materials as an excellent siRNA delivery carrier may considerably enhance the delivery efficiency of siRNA. Therefore, photothermal and RNA interfering (RNAi) synergistic therapy has recently aroused extensive attention in tumor treatment. In this review, we mainly summarize the recent advances of photothermal and RNAi synergistic therapy, including some synergistic therapeutic nanoplatforms of inorganic and organic photothermal materials and other combined therapies such as combining with small molecular antitumor agents or PDT/imaging. The combination of various treatment techniques may considerably improve the synergistic therapeutic effect of PTT and RNAi in the treatment of cancers.
2021, 32(3): 1017-1019
doi: 10.1016/j.cclet.2020.08.038
Abstract:
A new kind of emissive small-molecular organic cage has been developed via the combination of coupling and condensation reactions, which shows outstanding solubility, structural stability and potential spatial isomeric chirality. Interestingly, through the introduction of proper donor and acceptor units, this emissive organic cage is the first among organic cages to exhibit red aggregation-induced delayed fluorescence with photoluminescence emission at 603 nm. The finding not only expands the types of emissive small-molecular organic cages, but also represents an important step for further development of red delayed fluorescence materials with good solubility and aggregation-induced emission feature.
A new kind of emissive small-molecular organic cage has been developed via the combination of coupling and condensation reactions, which shows outstanding solubility, structural stability and potential spatial isomeric chirality. Interestingly, through the introduction of proper donor and acceptor units, this emissive organic cage is the first among organic cages to exhibit red aggregation-induced delayed fluorescence with photoluminescence emission at 603 nm. The finding not only expands the types of emissive small-molecular organic cages, but also represents an important step for further development of red delayed fluorescence materials with good solubility and aggregation-induced emission feature.
2021, 32(3): 1020-1024
doi: 10.1016/j.cclet.2020.09.035
Abstract:
In continuation of our efforts toward the discovery of potent HIV-1 NNRTIs with diverse structures, a series of novel S-DACO analogues of 6-(2-cyclohexyl-1-alkyl)-2-(2-oxo-2-phenyl-ethylsulfanyl)pyrimidin-4(3H)-ones were designed, synthesized and evaluated for their antiviral activities in MT-4 cells. Most of these new compounds showed moderate to good activities against wild type HIV-1 with IC50 values ranging from 7.55 μmol/L to 0.018 μmol/L. Among them, compound 5c was identified as the most promising inhibitor against HIV-1 replication with an IC50 = 0.018 μmol/L, CC50 = 194 μmol/L, and SI = 12791, which was much more potent than the reference drugs NVP and DLV and comparable to AZT and EFV. In addition, 5c also exhibited improved activity against double mutant HIV-1 strain RES056 compared to that of the reference drugs NVP/DLV and DB02. The preliminary structure-activity relationship (SAR) and molecular modeling studies were also discussed, which provides some useful indications for guiding the further rational design of new S-DACO analogues.
In continuation of our efforts toward the discovery of potent HIV-1 NNRTIs with diverse structures, a series of novel S-DACO analogues of 6-(2-cyclohexyl-1-alkyl)-2-(2-oxo-2-phenyl-ethylsulfanyl)pyrimidin-4(3H)-ones were designed, synthesized and evaluated for their antiviral activities in MT-4 cells. Most of these new compounds showed moderate to good activities against wild type HIV-1 with IC50 values ranging from 7.55 μmol/L to 0.018 μmol/L. Among them, compound 5c was identified as the most promising inhibitor against HIV-1 replication with an IC50 = 0.018 μmol/L, CC50 = 194 μmol/L, and SI = 12791, which was much more potent than the reference drugs NVP and DLV and comparable to AZT and EFV. In addition, 5c also exhibited improved activity against double mutant HIV-1 strain RES056 compared to that of the reference drugs NVP/DLV and DB02. The preliminary structure-activity relationship (SAR) and molecular modeling studies were also discussed, which provides some useful indications for guiding the further rational design of new S-DACO analogues.
2021, 32(3): 1025-1028
doi: 10.1016/j.cclet.2020.08.001
Abstract:
Nanoparticle surface property is crucial for circulation stability, cellullar uptake and other biological characteristics. Zwitterionic pillar[n]arenes (ZPns) were used to coat gold nanoparticles (GNPs) via host-guest interaction. The resulting GNPs demonstrated higher stability in blood serum compared to polyethylene glycol (PEG)-coated GNPs. ZPn-coated GNPs were responsive to UV-irradiation, competitive displacement and acidic pH. UV-irradiation or competitive displacement could lead to the removal of ZPn coating to expose GNPs, which enhanced cell uptake efficiency by 5.9- and 7.4-fold, respectively.
Nanoparticle surface property is crucial for circulation stability, cellullar uptake and other biological characteristics. Zwitterionic pillar[n]arenes (ZPns) were used to coat gold nanoparticles (GNPs) via host-guest interaction. The resulting GNPs demonstrated higher stability in blood serum compared to polyethylene glycol (PEG)-coated GNPs. ZPn-coated GNPs were responsive to UV-irradiation, competitive displacement and acidic pH. UV-irradiation or competitive displacement could lead to the removal of ZPn coating to expose GNPs, which enhanced cell uptake efficiency by 5.9- and 7.4-fold, respectively.
2021, 32(3): 1029-1032
doi: 10.1016/j.cclet.2020.09.012
Abstract:
Irradiated by visible light, the recyclable (PhTe)2-catalyzed oxidative deoximation reaction could occur under mild conditions. In comparison with the thermo reaction, the method employed reduced catalyst loading (1 mol% vs. 2.5 mol%), but afforded elevated product yields with expanded substrate scope. This work demonstrated that for the organotellurium-catalyzed reactions, visible light might be an even more precise driving energy than heating because it could break the Te-Te bond accurately to generate the active free radical catalytic intermediates without damaging the fragile substituents (e.g., heterocycles) of substrates. The use of O2 instead of explosive H2O2 as oxidant affords safer reaction conditions from the large-scale application viewpoint.
Irradiated by visible light, the recyclable (PhTe)2-catalyzed oxidative deoximation reaction could occur under mild conditions. In comparison with the thermo reaction, the method employed reduced catalyst loading (1 mol% vs. 2.5 mol%), but afforded elevated product yields with expanded substrate scope. This work demonstrated that for the organotellurium-catalyzed reactions, visible light might be an even more precise driving energy than heating because it could break the Te-Te bond accurately to generate the active free radical catalytic intermediates without damaging the fragile substituents (e.g., heterocycles) of substrates. The use of O2 instead of explosive H2O2 as oxidant affords safer reaction conditions from the large-scale application viewpoint.
2021, 32(3): 1033-1036
doi: 10.1016/j.cclet.2020.09.041
Abstract:
An electrochemical amino-azidation of 2-aminostyrene with sodium azide (NaN3) was developed, which can be carried out smoothly in water under metal-free condition, affording a series of 3-azido indolines with high yields.
An electrochemical amino-azidation of 2-aminostyrene with sodium azide (NaN3) was developed, which can be carried out smoothly in water under metal-free condition, affording a series of 3-azido indolines with high yields.
2021, 32(3): 1037-1040
doi: 10.1016/j.cclet.2020.09.019
Abstract:
Luminescent conjugated network polymer is one of the most promising chemo-sensors owing to their good chemical/optical stability and multiple functionalization. Herein, three conjugated network polymers were prepared by using aggregation-induced emission active 1, 1, 2, 2-tetrakis(4-formyl-(1, 1'-biphenyl))-ethane (TFBE) unit as monomer and hydrazine as linker. Through regulating the synthetical condition, the polymeric network can form either uniform two-dimensional azine-linked nanosheets (A-NS), conjugated microporous polymers (A-CMP) or covalent organic frameworks (A-COF). All of these polymers exhibited good stability and high fluorescence quantum efficiency with the quantum yield of 6.31% for A-NS, 5.26% for A-CMP, and 5.80% for A-COF, as well as fast and selective fluorescence quenching response to 2, 4, 6-trinitrophenol (TNP). And the best TNP sensing performance with the Stern-Volmer constants (Ksv) values up to 8×105 L/mol and a detection limit of 0.09 μmol/L was obtained for A-NS. The study explores various strategies to construct conjugated polymers with different nanoarchitectures based on the same building block for sensitive detection of explosives.
Luminescent conjugated network polymer is one of the most promising chemo-sensors owing to their good chemical/optical stability and multiple functionalization. Herein, three conjugated network polymers were prepared by using aggregation-induced emission active 1, 1, 2, 2-tetrakis(4-formyl-(1, 1'-biphenyl))-ethane (TFBE) unit as monomer and hydrazine as linker. Through regulating the synthetical condition, the polymeric network can form either uniform two-dimensional azine-linked nanosheets (A-NS), conjugated microporous polymers (A-CMP) or covalent organic frameworks (A-COF). All of these polymers exhibited good stability and high fluorescence quantum efficiency with the quantum yield of 6.31% for A-NS, 5.26% for A-CMP, and 5.80% for A-COF, as well as fast and selective fluorescence quenching response to 2, 4, 6-trinitrophenol (TNP). And the best TNP sensing performance with the Stern-Volmer constants (Ksv) values up to 8×105 L/mol and a detection limit of 0.09 μmol/L was obtained for A-NS. The study explores various strategies to construct conjugated polymers with different nanoarchitectures based on the same building block for sensitive detection of explosives.
2021, 32(3): 1041-1045
doi: 10.1016/j.cclet.2020.08.044
Abstract:
Structure-efficacy effect of small molecular drug attracts wide attentions, but it has always been ignored in nanomedicine research. To reveal the efficacy modulation of nanomedicine, we developed a new type of paclitaxel (PTX)-conjugated gold nanoparticles (PTX-conjugated GNPs) to investigate the influence of drug position in controlling their in vitro properties and in vivo performance. Two therapeutic ligands (TA-PEG-NH-N=PTX and TA-PTX=N-NH-PEG) were synthesized to conjugate PTX on the surface of GNPs at different positions, locating on the surface of gold conjugate and inserting between GNPs and polyethylene glycol (PEG, molecular weight 1000 Da), respectively. It was found that PEG-PTX@GNPs with PTX located between GNP and PEG exhibited higher aqueous solubility, biocompatibility, and stability. In addition, an acid sensitive hydrazone bond has been inserted between PTX and PEG in both ligands for drug release of PTX and PTX-PEG segment, respectively, at the tumor site. Further release of PTX from PTX-PEG segment is based on the esterase hydrolysis of an ester bond between PTX and PEG. This two-step drug release mechanism offers PEG-PTX@GNPs effective and sustained release behavior for desirable anticancer activity, enhanced therapeutic efficacy, and lower systematic toxicity in Heps-bearing animal models.
Structure-efficacy effect of small molecular drug attracts wide attentions, but it has always been ignored in nanomedicine research. To reveal the efficacy modulation of nanomedicine, we developed a new type of paclitaxel (PTX)-conjugated gold nanoparticles (PTX-conjugated GNPs) to investigate the influence of drug position in controlling their in vitro properties and in vivo performance. Two therapeutic ligands (TA-PEG-NH-N=PTX and TA-PTX=N-NH-PEG) were synthesized to conjugate PTX on the surface of GNPs at different positions, locating on the surface of gold conjugate and inserting between GNPs and polyethylene glycol (PEG, molecular weight 1000 Da), respectively. It was found that PEG-PTX@GNPs with PTX located between GNP and PEG exhibited higher aqueous solubility, biocompatibility, and stability. In addition, an acid sensitive hydrazone bond has been inserted between PTX and PEG in both ligands for drug release of PTX and PTX-PEG segment, respectively, at the tumor site. Further release of PTX from PTX-PEG segment is based on the esterase hydrolysis of an ester bond between PTX and PEG. This two-step drug release mechanism offers PEG-PTX@GNPs effective and sustained release behavior for desirable anticancer activity, enhanced therapeutic efficacy, and lower systematic toxicity in Heps-bearing animal models.
2021, 32(3): 1046-1050
doi: 10.1016/j.cclet.2020.03.066
Abstract:
Celastrol, a Chinese herbal medicine, has exhibited anticancer activity in many types of cancer cells. However, the further clinical application of celastrol is restricted by its poor water solubility and serious side effects. Furthermore, the apoptosis mechanism of tumor cells induced by celastrol has not been exhausted yet. In this study, we developed a reduction sensitive polymeric vector for tumor-targeted celastrol delivery. And our researches indicated that the celastrol could be delivered by reduction-sensitive nanomedicine (RSNMs) with a controlled release strategy. Meanwhile, the cell uptake results indicated that excellent reduction-sensitive behavior of RSNMs could effectively accelerate celastrol into the human retinoblastoma (RB) cell. The cell cytotoxicity assay demonstrated that celastrol inhibited proliferation of human RB Y79 cells growth in a dose-dependent manner. Furthermore, the results of flow cytometry and terminal dUTP nick-end labeling (TUNEL) staining showed that celastrol induced apoptosis of the RB Y79 cells, and revealed a time-dependent increase in apoptosis induction of RB Y79 cells. The results of western blotting showed that celastrol induced the apoptosis of human RB Y79 cells involving the activation of caspase-3 and caspase-9. In conclusion, our results revealed that RSNMs may be utilized as a novel therapy for retinoblastoma.
Celastrol, a Chinese herbal medicine, has exhibited anticancer activity in many types of cancer cells. However, the further clinical application of celastrol is restricted by its poor water solubility and serious side effects. Furthermore, the apoptosis mechanism of tumor cells induced by celastrol has not been exhausted yet. In this study, we developed a reduction sensitive polymeric vector for tumor-targeted celastrol delivery. And our researches indicated that the celastrol could be delivered by reduction-sensitive nanomedicine (RSNMs) with a controlled release strategy. Meanwhile, the cell uptake results indicated that excellent reduction-sensitive behavior of RSNMs could effectively accelerate celastrol into the human retinoblastoma (RB) cell. The cell cytotoxicity assay demonstrated that celastrol inhibited proliferation of human RB Y79 cells growth in a dose-dependent manner. Furthermore, the results of flow cytometry and terminal dUTP nick-end labeling (TUNEL) staining showed that celastrol induced apoptosis of the RB Y79 cells, and revealed a time-dependent increase in apoptosis induction of RB Y79 cells. The results of western blotting showed that celastrol induced the apoptosis of human RB Y79 cells involving the activation of caspase-3 and caspase-9. In conclusion, our results revealed that RSNMs may be utilized as a novel therapy for retinoblastoma.
2021, 32(3): 1051-1054
doi: 10.1016/j.cclet.2020.07.034
Abstract:
Herein, copper ion doped calcium alginate (Cu2+/CaAlg) composite hydrogel filtration membranes were prepared by using natural polymer sodium alginate (NaAlg) as raw material. The thermal stability and structure of the composite membranes were characterized by thermogravimetric analysis and infrared spectroscopy. The mechanical strength, anti-fouling performance, hydrophilicity and filtration performance of the membrane were studied. The results show that Cu2+/CaAlg hydrogel membrane has excellent mechanical properties and thermal stability. The anti-swelling ability of the membrane was greatly enhanced by doping Cu2+. After three alternate filtration cycles, the flux recovery rate of Cu2+/CaAlg hydrogel membrane can still reach 85%, indicating that the membrane has good anti-pollution performance. When the operation pressure was 0.1 MPa, the rejection of coomassie brilliant blue G250 reached 99.8% with a flux of 46.3 L m-2 h-1, while the Na2SO4 rejectionwas less than 10.0%. The Cu2+/CaAlg membrane was recycled after 24 h in the filtration process, and its flux and rejection rate did not decrease significantly, indicating that the hydrogel membrane has long-term application potential. The Cu2+/CaAlg membrane has a wide range of applications prospect in dye desalination, fine separation and biopharmaceutical technology fields.
Herein, copper ion doped calcium alginate (Cu2+/CaAlg) composite hydrogel filtration membranes were prepared by using natural polymer sodium alginate (NaAlg) as raw material. The thermal stability and structure of the composite membranes were characterized by thermogravimetric analysis and infrared spectroscopy. The mechanical strength, anti-fouling performance, hydrophilicity and filtration performance of the membrane were studied. The results show that Cu2+/CaAlg hydrogel membrane has excellent mechanical properties and thermal stability. The anti-swelling ability of the membrane was greatly enhanced by doping Cu2+. After three alternate filtration cycles, the flux recovery rate of Cu2+/CaAlg hydrogel membrane can still reach 85%, indicating that the membrane has good anti-pollution performance. When the operation pressure was 0.1 MPa, the rejection of coomassie brilliant blue G250 reached 99.8% with a flux of 46.3 L m-2 h-1, while the Na2SO4 rejectionwas less than 10.0%. The Cu2+/CaAlg membrane was recycled after 24 h in the filtration process, and its flux and rejection rate did not decrease significantly, indicating that the hydrogel membrane has long-term application potential. The Cu2+/CaAlg membrane has a wide range of applications prospect in dye desalination, fine separation and biopharmaceutical technology fields.
2021, 32(3): 1055-1060
doi: 10.1016/j.cclet.2020.08.009
Abstract:
Most recently, cobalt sulfide (CoS) nanospheres (NSs) have been demonstrated as an ideal high-efficient photothermal agent for tumor elimination. However, the surface of CoS NSs is lack of functional chemical groups or active radicals to incorporate therapeutic agents, which tremendously hinders their versatile utilization in medical field. Here, surface activation of CoS NSs was realized through the growth of polydopamine (PDA) in situ via alkaline-triggered polymerization. Upon the formation of CoS@PDA NSs, thiol-polyethylene glycol (SH-PEG) and chemotherapeutic agent of doxorubicin (DOX) were loaded onto the particle surface by means of π-π electrostatic interaction and Michael addition reactions. As-synthesized CoS@PDA/PEG/DOX (CoPPD) NSs exhibited an admirable photothermal property and high loading capacity of DOX (44.6%). Furthermore, drug release can be accelerated under a more acidic pH condition mimicking tumor microenvironment (TME), ascribed to the protonation of amino group in DOX molecules. Finally, a strong chemotherapeutic-enhanced photothermal therapeutic effect was demonstrated toward solid tumor under near-infrared (NIR) light irradiation without causing significant systemic toxicity. In this regard, this paradigm may offer valuable guidance for the design of multifunctional CoS-based nanoagents for medical treatment.
Most recently, cobalt sulfide (CoS) nanospheres (NSs) have been demonstrated as an ideal high-efficient photothermal agent for tumor elimination. However, the surface of CoS NSs is lack of functional chemical groups or active radicals to incorporate therapeutic agents, which tremendously hinders their versatile utilization in medical field. Here, surface activation of CoS NSs was realized through the growth of polydopamine (PDA) in situ via alkaline-triggered polymerization. Upon the formation of CoS@PDA NSs, thiol-polyethylene glycol (SH-PEG) and chemotherapeutic agent of doxorubicin (DOX) were loaded onto the particle surface by means of π-π electrostatic interaction and Michael addition reactions. As-synthesized CoS@PDA/PEG/DOX (CoPPD) NSs exhibited an admirable photothermal property and high loading capacity of DOX (44.6%). Furthermore, drug release can be accelerated under a more acidic pH condition mimicking tumor microenvironment (TME), ascribed to the protonation of amino group in DOX molecules. Finally, a strong chemotherapeutic-enhanced photothermal therapeutic effect was demonstrated toward solid tumor under near-infrared (NIR) light irradiation without causing significant systemic toxicity. In this regard, this paradigm may offer valuable guidance for the design of multifunctional CoS-based nanoagents for medical treatment.
2021, 32(3): 1061-1065
doi: 10.1016/j.cclet.2020.09.024
Abstract:
By pairing two fluorophores according to their optical properties such as absorption spectral overlap and absorptivity, fluorescent quantum yield and emission spectral separation, a bifunctional fluorescent probe, TQBF-NBD, was rationally designed and synthesized to discriminatively sense Hcy/Cys and GSH with good selectivity and sensitivity. It is noted that this probe could work under a single-wavelength excitation and displayed a mega-large Stokes shift. TQBF-NBD reacted with Hcy/Cys to give a mixed green-red fluorescence and displayed a red fluorescence upon the treatment with GSH. Distinguishable imaging of intracellular Hcy/Cys from GSH with the help of TQBF-NBD was realized in living cells and zebrafish.
By pairing two fluorophores according to their optical properties such as absorption spectral overlap and absorptivity, fluorescent quantum yield and emission spectral separation, a bifunctional fluorescent probe, TQBF-NBD, was rationally designed and synthesized to discriminatively sense Hcy/Cys and GSH with good selectivity and sensitivity. It is noted that this probe could work under a single-wavelength excitation and displayed a mega-large Stokes shift. TQBF-NBD reacted with Hcy/Cys to give a mixed green-red fluorescence and displayed a red fluorescence upon the treatment with GSH. Distinguishable imaging of intracellular Hcy/Cys from GSH with the help of TQBF-NBD was realized in living cells and zebrafish.
2021, 32(3): 1066-1070
doi: 10.1016/j.cclet.2020.09.009
Abstract:
The abnormal aggregation of amyloid-beta (Aβ) has been widely believed to play an important role in the pathogenesis of Alzheimer's disease (AD), which is also recognized as one of the main biomarkers for AD diagnosis. The peptide sequence Lys-Leu-Val-Phe-Phe (KLVFF) is considered as the main driver of the fibrillation of Aβ, which also can be utilized to target Aβ and inhibit its aggregation. In this study, KLVFF and Fmoc-KLVFF fluorescent nanoparticles were self-assembled through zinc coordination and π-π stacking. The recognition of Aβ aggregates including oligomers and fibrils by fluorescent nanoparticles can be realized through aromatic, hydrophobic, and hydrogen-bond interactions. The fluorescent nanoprobes can distinguish Aβ aggregation formats and detect Aβ at the limit of 1 pg/mL (S/N = 3). Hence, the detection of Aβ aggregates by fluorescent peptide nanoparticles has great potential for AD diagnosis and progression prediction.
The abnormal aggregation of amyloid-beta (Aβ) has been widely believed to play an important role in the pathogenesis of Alzheimer's disease (AD), which is also recognized as one of the main biomarkers for AD diagnosis. The peptide sequence Lys-Leu-Val-Phe-Phe (KLVFF) is considered as the main driver of the fibrillation of Aβ, which also can be utilized to target Aβ and inhibit its aggregation. In this study, KLVFF and Fmoc-KLVFF fluorescent nanoparticles were self-assembled through zinc coordination and π-π stacking. The recognition of Aβ aggregates including oligomers and fibrils by fluorescent nanoparticles can be realized through aromatic, hydrophobic, and hydrogen-bond interactions. The fluorescent nanoprobes can distinguish Aβ aggregation formats and detect Aβ at the limit of 1 pg/mL (S/N = 3). Hence, the detection of Aβ aggregates by fluorescent peptide nanoparticles has great potential for AD diagnosis and progression prediction.
2021, 32(3): 1071-1076
doi: 10.1016/j.cclet.2020.03.062
Abstract:
Azithromycin loaded fumaryl diketopiperazine (FDKP) dry powder inhalationwas designed and prepared for the treatment of community-acquired pneumonia. The solubility of FDKP and stability of azithromycin solution was investigated. Formulation of azithromycin loaded FDKP microparticle was investigated and optimized by the single factor experiment. High-pressure homogenization and spray drying conditions were also optimized to prepare the particles by spray drying azithromycin dissolved FDKP microparticle suspension at pH 4.5. The in vitro antibacterial efficiency and in vitro dispersion performance was also investigated to confirm the antibacterial efficiency, dispersion and deposition behavers. FDKP/azithromycin mass ratio (3:2) was the optimized formulation of azithromycin loaded FDKP microparticle with the maximal drug loading efficiency. High-pressure homogenization and spray drying conditions were also optimized. The in vitro antibacterial results indicated that only with the antibiotic concentration higher than mutant prevention concentration could totally inhibit the reproduction of bacteria. In vitro dispersion performance of azithromycin loaded FDKP microparticles (AZM@FDKP-MPs) also shows remarkable improvement of dispersion and deposition behavers of AZM. AZM@FDKP-MPs dry powder inhalation as a targeting delivery route has better potential for lung infection treatment.
Azithromycin loaded fumaryl diketopiperazine (FDKP) dry powder inhalationwas designed and prepared for the treatment of community-acquired pneumonia. The solubility of FDKP and stability of azithromycin solution was investigated. Formulation of azithromycin loaded FDKP microparticle was investigated and optimized by the single factor experiment. High-pressure homogenization and spray drying conditions were also optimized to prepare the particles by spray drying azithromycin dissolved FDKP microparticle suspension at pH 4.5. The in vitro antibacterial efficiency and in vitro dispersion performance was also investigated to confirm the antibacterial efficiency, dispersion and deposition behavers. FDKP/azithromycin mass ratio (3:2) was the optimized formulation of azithromycin loaded FDKP microparticle with the maximal drug loading efficiency. High-pressure homogenization and spray drying conditions were also optimized. The in vitro antibacterial results indicated that only with the antibiotic concentration higher than mutant prevention concentration could totally inhibit the reproduction of bacteria. In vitro dispersion performance of azithromycin loaded FDKP microparticles (AZM@FDKP-MPs) also shows remarkable improvement of dispersion and deposition behavers of AZM. AZM@FDKP-MPs dry powder inhalation as a targeting delivery route has better potential for lung infection treatment.
2021, 32(3): 1077-1080
doi: 10.1016/j.cclet.2020.07.049
Abstract:
Here, the selective adsorption behaviors of guest molecule COR in two hexamer host grids were investigated by means of scanning tunnelling microscope (STM). The assembled structures of small functional organic molecules TTBTA and TATBA were thermodynamically stable. Interestingly, the introduction of the guest molecule COR destroyed the original hexamer structure of TTBTA and combined with it to form a new triangular host-guest system. Different from TTBTA, the introduction of the guest molecule COR did not affect the six-membered ring structure of TATBA. Furthermore, the co-assembly structure of TTBTA/TATBA/COR was established and the guest molecule COR showed preferential adsorption to the TATBA host grid. Density functional theory (DFT) calculations had been performed to disclose the mechanism of the involved assemblies.
Here, the selective adsorption behaviors of guest molecule COR in two hexamer host grids were investigated by means of scanning tunnelling microscope (STM). The assembled structures of small functional organic molecules TTBTA and TATBA were thermodynamically stable. Interestingly, the introduction of the guest molecule COR destroyed the original hexamer structure of TTBTA and combined with it to form a new triangular host-guest system. Different from TTBTA, the introduction of the guest molecule COR did not affect the six-membered ring structure of TATBA. Furthermore, the co-assembly structure of TTBTA/TATBA/COR was established and the guest molecule COR showed preferential adsorption to the TATBA host grid. Density functional theory (DFT) calculations had been performed to disclose the mechanism of the involved assemblies.
2021, 32(3): 1081-1085
doi: 10.1016/j.cclet.2020.08.042
Abstract:
Using the global particle-swarm optimization method and density functional theory, we predict a new stable two-dimensional layered material: MgSiP2 with a low-buckled honeycomb lattice. Our HSE06 calculation shows that MgSiP2 is an indirect-gap semiconductor with a band-gap of 1.20 eV, closed to that of bulk silicon. More remarkably, MgSiP2 exhibits worthwhile anisotropy along with electron and hole carrier mobility. A ultrahigh electron mobility is even up to 1.29×104 cm2 V-1 s-1, while the hole mobility is nearly zero along the a direction. The large difference of the mobility between electron and hole together with the suitable band-gap suggest that MgSiP2 may be a good candidate for solar cell or photochemical catalysis material. Furthermore, we explore MgSiP2 as an anode for sodium-ion batteries. Upon Na adsorption, the semiconducting MgSiP2 transforms to a metallic state, ensuring good electrical conductivity. A maximum theoretical capacity of 1406 mAh/g, a small volume change (within 9.5%), a small diffusion barrier (~0.16 eV) and low average open-circuit voltages (~0.15 V) were found for MgSiP2 as an anode for sodium-ion batteries. These results are helpful to deepen the understanding of MgSiP2 as a nanoelectronic device and a potential anode for Na-ion batteries.
Using the global particle-swarm optimization method and density functional theory, we predict a new stable two-dimensional layered material: MgSiP2 with a low-buckled honeycomb lattice. Our HSE06 calculation shows that MgSiP2 is an indirect-gap semiconductor with a band-gap of 1.20 eV, closed to that of bulk silicon. More remarkably, MgSiP2 exhibits worthwhile anisotropy along with electron and hole carrier mobility. A ultrahigh electron mobility is even up to 1.29×104 cm2 V-1 s-1, while the hole mobility is nearly zero along the a direction. The large difference of the mobility between electron and hole together with the suitable band-gap suggest that MgSiP2 may be a good candidate for solar cell or photochemical catalysis material. Furthermore, we explore MgSiP2 as an anode for sodium-ion batteries. Upon Na adsorption, the semiconducting MgSiP2 transforms to a metallic state, ensuring good electrical conductivity. A maximum theoretical capacity of 1406 mAh/g, a small volume change (within 9.5%), a small diffusion barrier (~0.16 eV) and low average open-circuit voltages (~0.15 V) were found for MgSiP2 as an anode for sodium-ion batteries. These results are helpful to deepen the understanding of MgSiP2 as a nanoelectronic device and a potential anode for Na-ion batteries.
Facile preparation of compact LTA molecular sieve membranes on polyethyleneimine modified substrates
2021, 32(3): 1086-1088
doi: 10.1016/j.cclet.2020.07.047
Abstract:
A facile preparation strategy was proposed for preparation of compact zeolite LTA membranes on polyethyleneimine (PEI) modified substrates without seeding. Through the functionalization of substrates by using PEI, compact LTA membranes can be formed on various kinds of substrates. A well-intergrown and phase-pure LTA membrane with a thickness of about 3.0 μm is successfully prepared on the α-Al2O3 disk after crystallization for 24 h at 60 ℃. Besides LTA membrane, well-intergrown zeolite FAU membranes can also be formed on PEI-modified α-Al2O3 substrates, suggesting the universality of this strategy. The zeolite LTA membranes synthesized on PEI-modified α-Al2O3 tubes were evaluated for the separation of alcohols/water mixture through pervaporation. The as-synthesized zeolite LTA membranes display high pervaporation performances. For the separation of 10 wt% iso-propanol/water solution at 90 ℃, a high separation factor of 44991 and a water flux of 1.73 kg m-2 h-1 are achieved.
A facile preparation strategy was proposed for preparation of compact zeolite LTA membranes on polyethyleneimine (PEI) modified substrates without seeding. Through the functionalization of substrates by using PEI, compact LTA membranes can be formed on various kinds of substrates. A well-intergrown and phase-pure LTA membrane with a thickness of about 3.0 μm is successfully prepared on the α-Al2O3 disk after crystallization for 24 h at 60 ℃. Besides LTA membrane, well-intergrown zeolite FAU membranes can also be formed on PEI-modified α-Al2O3 substrates, suggesting the universality of this strategy. The zeolite LTA membranes synthesized on PEI-modified α-Al2O3 tubes were evaluated for the separation of alcohols/water mixture through pervaporation. The as-synthesized zeolite LTA membranes display high pervaporation performances. For the separation of 10 wt% iso-propanol/water solution at 90 ℃, a high separation factor of 44991 and a water flux of 1.73 kg m-2 h-1 are achieved.
2021, 32(3): 1089-1094
doi: 10.1016/j.cclet.2020.08.031
Abstract:
Using particle swarm optimization (PSO) methodology for crystal structure prediction, we predicted a novel two-dimensional (2D) monolayer of silicide diphosphorus compound: SiP2, which exhibits good stability as examined via cohesive energy, mechanical criteria, molecular dynamics simulation and all positive phonon spectrum, respectively. The SiP2 monolayer is an indirect semiconductor with the band gap as 1.8484 eV (PBE) or 2.681 eV (HSE06), which makes it more advantageous for high-frequency-response optoelectronic materials. Moreover, the monolayer is a relatively hard auxetic material with negative Possion's ratios, and also possesses a ultrahigh carrier mobility (1.069×105 cm2 V-1 s-1) which is approximately four times the maximum value in phosphorene and comparable to the value of graphene and CP monolayers. Furthermore, the effects of strains on band structures and optical properties of SiP2 monolayer have been studied, as well as CO2 molecules can be strongly chemically adsorbed on the SiP2 monolayer. A semiconductor-to-metal transition for -9.5% strain ratio case and a huge optical absorption capacity on the order of 106 cm-1 in visible region present. These theoretical findings endow SiP2 Monolayer to be a novel 2D material holding great promises for applications in high-performance electronics, optoelectronics, mechanics and CO2 capturing material.
Using particle swarm optimization (PSO) methodology for crystal structure prediction, we predicted a novel two-dimensional (2D) monolayer of silicide diphosphorus compound: SiP2, which exhibits good stability as examined via cohesive energy, mechanical criteria, molecular dynamics simulation and all positive phonon spectrum, respectively. The SiP2 monolayer is an indirect semiconductor with the band gap as 1.8484 eV (PBE) or 2.681 eV (HSE06), which makes it more advantageous for high-frequency-response optoelectronic materials. Moreover, the monolayer is a relatively hard auxetic material with negative Possion's ratios, and also possesses a ultrahigh carrier mobility (1.069×105 cm2 V-1 s-1) which is approximately four times the maximum value in phosphorene and comparable to the value of graphene and CP monolayers. Furthermore, the effects of strains on band structures and optical properties of SiP2 monolayer have been studied, as well as CO2 molecules can be strongly chemically adsorbed on the SiP2 monolayer. A semiconductor-to-metal transition for -9.5% strain ratio case and a huge optical absorption capacity on the order of 106 cm-1 in visible region present. These theoretical findings endow SiP2 Monolayer to be a novel 2D material holding great promises for applications in high-performance electronics, optoelectronics, mechanics and CO2 capturing material.
2021, 32(3): 1095-1100
doi: 10.1016/j.cclet.2020.08.022
Abstract:
Metallic zinc is attractive anode material of rechargeable aqueous Zn-based batteries due to its ambient stability, high volumetric capacity, and abundant reserves. Nonetheless, Zn anodes suffer from issues such as low coulombic efficiency (CE), large polarization and dendrite formation. Herein, uniform Zn electrodeposition is reported on carbon substrates by selective nitrogen doping. Combined experimental and theoretical investigations demonstrate that pyrrolic and pyridinic nitrogen doped in carbon play beneficial effect as zinc-philic sites to direct nucleation and growth of metallic Zn, while negligible effect is observed for graphite nitrogen in Zn plating. The carbon cloth with modified amount of doped pyrrolic and pyridinic nitrogen stabilizes Zn plating/stripping with 99.3% CE after 300 cycles and significantly increases the deliverable capacity at high depth of charge and discharge compared to undoped carbon substrate and Zn foil. This work provides a better understanding of heteroatom doping effect in design and preparation of stable 3D carbon-supported zinc anode.
Metallic zinc is attractive anode material of rechargeable aqueous Zn-based batteries due to its ambient stability, high volumetric capacity, and abundant reserves. Nonetheless, Zn anodes suffer from issues such as low coulombic efficiency (CE), large polarization and dendrite formation. Herein, uniform Zn electrodeposition is reported on carbon substrates by selective nitrogen doping. Combined experimental and theoretical investigations demonstrate that pyrrolic and pyridinic nitrogen doped in carbon play beneficial effect as zinc-philic sites to direct nucleation and growth of metallic Zn, while negligible effect is observed for graphite nitrogen in Zn plating. The carbon cloth with modified amount of doped pyrrolic and pyridinic nitrogen stabilizes Zn plating/stripping with 99.3% CE after 300 cycles and significantly increases the deliverable capacity at high depth of charge and discharge compared to undoped carbon substrate and Zn foil. This work provides a better understanding of heteroatom doping effect in design and preparation of stable 3D carbon-supported zinc anode.
2021, 32(3): 1101-1105
doi: 10.1016/j.cclet.2020.08.023
Abstract:
Multishelled hollow structures have drawn increasing interest because of their peculiar compartmentation environments and physicochemical properties. In this work, deformable double-shelled hollow mesoporous organosilica nanocapsules (DDHMONs) were successfully synthesized by a multi-interfacial etching strategy. The obtained DDHMONs have a double-shelled structure with aninorganic-organic hybrid framework, a uniform outer layer (~320 nm) and inner layer (~180 nm), ordered mesochannels (~2.21 nm), and a large specific surface area (~1233 m2/g). In vitro toxicity tests show that the DDHMONs have excellent biocompatibility when coincubated with human breast cancer cells. In addition, the anticancer substance doxorubicin (DOX) can be highly loaded in DDHMONs (~335 μg/mg). The results from flow cytometry together with confocal laser scanning microscopy show that DOX can be efficiently delivered into MCF-7 cells by DDHMONs, thus improving chemotherapeutic efficiency and demonstrating that DDHMONs have potential nanomedicine applications as anticancer agents.
Multishelled hollow structures have drawn increasing interest because of their peculiar compartmentation environments and physicochemical properties. In this work, deformable double-shelled hollow mesoporous organosilica nanocapsules (DDHMONs) were successfully synthesized by a multi-interfacial etching strategy. The obtained DDHMONs have a double-shelled structure with aninorganic-organic hybrid framework, a uniform outer layer (~320 nm) and inner layer (~180 nm), ordered mesochannels (~2.21 nm), and a large specific surface area (~1233 m2/g). In vitro toxicity tests show that the DDHMONs have excellent biocompatibility when coincubated with human breast cancer cells. In addition, the anticancer substance doxorubicin (DOX) can be highly loaded in DDHMONs (~335 μg/mg). The results from flow cytometry together with confocal laser scanning microscopy show that DOX can be efficiently delivered into MCF-7 cells by DDHMONs, thus improving chemotherapeutic efficiency and demonstrating that DDHMONs have potential nanomedicine applications as anticancer agents.
2021, 32(3): 1106-1110
doi: 10.1016/j.cclet.2020.08.024
Abstract:
Constructing 3D multifunctional conductive framework as stable sulfur cathode contributes to develop advanced lithium-sulfur (Li-S) batteries. Herein, a freestanding electrode with nickel foam framework and nitrogen doped porous carbon (PC) network is presented to encapsulate active sulfur for Li-S batteries. In such a mutually embedded architecture with high stability, the interconnected carbon network and nickel foam matrix can expedite ionic/electronic transport and sustain volume variations of sulfur. Furthermore, rationally designed porous structures provide sufficient internal space and large surface area for high active sulfur loading and polar polysulfides anchoring. Benefiting from the synergistic superiority, the Ni/PC-S cathode exhibits a high initial capacity of around 1200 mAh/g at 0.2 C, excellent rate performance, and high cycling stability with a low decay rate of 0.059% per cycle after 500 cycles. This work provides a useful strategy to exploit freestanding porous framework for diverse applications.
Constructing 3D multifunctional conductive framework as stable sulfur cathode contributes to develop advanced lithium-sulfur (Li-S) batteries. Herein, a freestanding electrode with nickel foam framework and nitrogen doped porous carbon (PC) network is presented to encapsulate active sulfur for Li-S batteries. In such a mutually embedded architecture with high stability, the interconnected carbon network and nickel foam matrix can expedite ionic/electronic transport and sustain volume variations of sulfur. Furthermore, rationally designed porous structures provide sufficient internal space and large surface area for high active sulfur loading and polar polysulfides anchoring. Benefiting from the synergistic superiority, the Ni/PC-S cathode exhibits a high initial capacity of around 1200 mAh/g at 0.2 C, excellent rate performance, and high cycling stability with a low decay rate of 0.059% per cycle after 500 cycles. This work provides a useful strategy to exploit freestanding porous framework for diverse applications.
2021, 32(3): 1111-1116
doi: 10.1016/j.cclet.2020.08.026
Abstract:
A template-free carbonization-activation route is developed to fabricate sub-nanopore-containing porous carbon by using a novel polypyrrole (PPy) hydrogel as a precursor. This design of PPy hydrogel precursor containing molecular-scale grids (diameter ~2.0 nm) allows for homogeneous N, O-codoping into the porous carbon scaffold during the pyrolysis process. A subsequent activation step produces activated porous carbons (APCs) with tailored pore structures, which renders the APCs abundant sub-nanopores on their surface to increase the specific capacitance as extra capacitance sites. Coupled with large specific surface area and abundant heteroatoms, the optimized APC4/1 displays excellent specific capacitance of 379 F/g for liquid-state supercapacitor and 230 F/g for solid-state supercapacitor. The solid-state supercapacitor shows a high energy density of 22.99 Wh/kg at power density of 420 W/kg, which is higher than most reported porous carbon materials and satisfy the urgent requirements of elementary power source for electric vehicles. Moreover, this method can be easily modified to fabricate sub-nanopore-containing porous carbons with preferred structures and compositions for many applications.
A template-free carbonization-activation route is developed to fabricate sub-nanopore-containing porous carbon by using a novel polypyrrole (PPy) hydrogel as a precursor. This design of PPy hydrogel precursor containing molecular-scale grids (diameter ~2.0 nm) allows for homogeneous N, O-codoping into the porous carbon scaffold during the pyrolysis process. A subsequent activation step produces activated porous carbons (APCs) with tailored pore structures, which renders the APCs abundant sub-nanopores on their surface to increase the specific capacitance as extra capacitance sites. Coupled with large specific surface area and abundant heteroatoms, the optimized APC4/1 displays excellent specific capacitance of 379 F/g for liquid-state supercapacitor and 230 F/g for solid-state supercapacitor. The solid-state supercapacitor shows a high energy density of 22.99 Wh/kg at power density of 420 W/kg, which is higher than most reported porous carbon materials and satisfy the urgent requirements of elementary power source for electric vehicles. Moreover, this method can be easily modified to fabricate sub-nanopore-containing porous carbons with preferred structures and compositions for many applications.
2021, 32(3): 1117-1120
doi: 10.1016/j.cclet.2020.08.030
Abstract:
The potassium-ion batteries (PIBs) have become the promising energy storage devices due to their relatively moderate cost and plenteous potassium resources. Whereas, the main drawback of PIBs is unsatisfactory electrochemical performance induced by the larger ionic radius of potassium ion. Herein, we report a well-designed, uniform-dispersed, and morphology-controllable zinc sulfide (ZnS) quantum dots loading on graphene as an anode in the PIBs. The directed uniform dispersion of the in-situ growing ZnS quantum dots (~2.8 nm in size) on graphene can mitigate the volume effect during the insertion-extraction process and shorten the migration path of potassium ions. As a result, the battery exhibits superior cycling stability (350.4 mAh/g over 200 cycles at 0.1 A/g) and rate performance (98.8 mAh/g at 2.0 A/g). We believe the design of active material with quantum dot-minimized size provides a novel route into PIBs and contributes to eliminating the major electrode failure issues of the system.
The potassium-ion batteries (PIBs) have become the promising energy storage devices due to their relatively moderate cost and plenteous potassium resources. Whereas, the main drawback of PIBs is unsatisfactory electrochemical performance induced by the larger ionic radius of potassium ion. Herein, we report a well-designed, uniform-dispersed, and morphology-controllable zinc sulfide (ZnS) quantum dots loading on graphene as an anode in the PIBs. The directed uniform dispersion of the in-situ growing ZnS quantum dots (~2.8 nm in size) on graphene can mitigate the volume effect during the insertion-extraction process and shorten the migration path of potassium ions. As a result, the battery exhibits superior cycling stability (350.4 mAh/g over 200 cycles at 0.1 A/g) and rate performance (98.8 mAh/g at 2.0 A/g). We believe the design of active material with quantum dot-minimized size provides a novel route into PIBs and contributes to eliminating the major electrode failure issues of the system.
2021, 32(3): 1121-1126
doi: 10.1016/j.cclet.2020.08.029
Abstract:
Catalytic oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) have garnered great attention as the key character in metal-air batteries. Herein, we developed a superior nonprecious bifunctional oxygen electrocatalyst, fabricated through spatial confinement of Fe/Fe3C nanocrystals in pyridinic N and Fe-Nx rich carbon nanotubes (Fe/Fe3C-N-CNTs). During ORR, the resultant electrocatalyst exhibits positive onset potential of 1.0 V (vs. RHE), large half-wave potentials of 0.88 V (vs. RHE), which is more positive than Pt/C (0.98 V and 0.83 V, respectively). Remarkably, Fe/Fe3C-N-CNTs exhibits outstanding durability and great methanol tolerance, exceeding Pt/C and most reported nonprecious metal-based oxygen reduction electrocatalysts. Moreover, Fe/Fe3C-N-CNTs show a markedly low potential at j =10 mA/cm2, small Tafel slopes and extremely high stability for OER. Impressively, the Fe/Fe3C-N-CNTs-based Zn-air batteries demonstrate high power density of 183 mW/cm2 and robust charge/discharge stability. It is revealed that the spatial confinement effect can impede the aggregation and corrosion of Fe/Fe3C nanocrystals. Meanwhile, Fe/Fe3C and Fe-Nx play synergistic effect on boosting the ORR/OER activity, which provides an important guideline for construction of inexpensive nonprecious metal-carbon hybrid nanomaterials.
Catalytic oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) have garnered great attention as the key character in metal-air batteries. Herein, we developed a superior nonprecious bifunctional oxygen electrocatalyst, fabricated through spatial confinement of Fe/Fe3C nanocrystals in pyridinic N and Fe-Nx rich carbon nanotubes (Fe/Fe3C-N-CNTs). During ORR, the resultant electrocatalyst exhibits positive onset potential of 1.0 V (vs. RHE), large half-wave potentials of 0.88 V (vs. RHE), which is more positive than Pt/C (0.98 V and 0.83 V, respectively). Remarkably, Fe/Fe3C-N-CNTs exhibits outstanding durability and great methanol tolerance, exceeding Pt/C and most reported nonprecious metal-based oxygen reduction electrocatalysts. Moreover, Fe/Fe3C-N-CNTs show a markedly low potential at j =10 mA/cm2, small Tafel slopes and extremely high stability for OER. Impressively, the Fe/Fe3C-N-CNTs-based Zn-air batteries demonstrate high power density of 183 mW/cm2 and robust charge/discharge stability. It is revealed that the spatial confinement effect can impede the aggregation and corrosion of Fe/Fe3C nanocrystals. Meanwhile, Fe/Fe3C and Fe-Nx play synergistic effect on boosting the ORR/OER activity, which provides an important guideline for construction of inexpensive nonprecious metal-carbon hybrid nanomaterials.
2021, 32(3): 1127-1130
doi: 10.1016/j.cclet.2020.08.033
Abstract:
CO oxidation at ceria surfaces has been studied for decades, and many efforts have been devoted to understanding the effect of surface reduction on the catalytic activity. In this work, we theoretically studied the CO oxidation on the clean and reduced CeO2(111) surfaces using different surface cells to determine the relationships between the reduction degrees and calculated reaction energetics. It is found that the calculated barrier for the direct reaction between CO and surface lattice O drastically decreases with the increase of surface reduction degree. From electronic analysis, we found that the surface reduction can lead to the occurrence of localized electrons at the surface Ce, which affects the charge distribution at surface O. As the result, the surface O becomes more negatively charged and therefore more active in reacting with CO. This work then suggests that the localized 4f electron reservoir of Ce can act as the "pseudo-anion" at reduced CeO2 surfaces to activate surface lattice O for catalytic oxidative reactions.
CO oxidation at ceria surfaces has been studied for decades, and many efforts have been devoted to understanding the effect of surface reduction on the catalytic activity. In this work, we theoretically studied the CO oxidation on the clean and reduced CeO2(111) surfaces using different surface cells to determine the relationships between the reduction degrees and calculated reaction energetics. It is found that the calculated barrier for the direct reaction between CO and surface lattice O drastically decreases with the increase of surface reduction degree. From electronic analysis, we found that the surface reduction can lead to the occurrence of localized electrons at the surface Ce, which affects the charge distribution at surface O. As the result, the surface O becomes more negatively charged and therefore more active in reacting with CO. This work then suggests that the localized 4f electron reservoir of Ce can act as the "pseudo-anion" at reduced CeO2 surfaces to activate surface lattice O for catalytic oxidative reactions.
2021, 32(3): 1131-1134
doi: 10.1016/j.cclet.2020.09.039
Abstract:
Size-controlled flow synthesis of nanoporous particles are of considerable interest for future industrial applications, however, is facing challenges due to lack of in-situ method for size-characterization in fluidic environment. We present that ultraviolet-visible (UV–vis) absorption spectroscopy can be integrated into a flow-synthesis system which was produced by femtosecond laser micromachining. The shift of the absorption peak position of the ex-situ and in-situ UV–vis spectra correlates to variation of size of porous metal-organic frameworks crystals. ZIF-67 crystals with a size in the range from 200 nm to 1025 nm are fabricated with the assistance of tri-ethylamine under monitoring of in-situ UV–vis spectra. The ZIF-67 crystals are converted into nanoporous carbons particles with controlled sizes. These materials show size-dependent performance in Na-ion battery and size-independent performance in metal/H2O seawater battery.
Size-controlled flow synthesis of nanoporous particles are of considerable interest for future industrial applications, however, is facing challenges due to lack of in-situ method for size-characterization in fluidic environment. We present that ultraviolet-visible (UV–vis) absorption spectroscopy can be integrated into a flow-synthesis system which was produced by femtosecond laser micromachining. The shift of the absorption peak position of the ex-situ and in-situ UV–vis spectra correlates to variation of size of porous metal-organic frameworks crystals. ZIF-67 crystals with a size in the range from 200 nm to 1025 nm are fabricated with the assistance of tri-ethylamine under monitoring of in-situ UV–vis spectra. The ZIF-67 crystals are converted into nanoporous carbons particles with controlled sizes. These materials show size-dependent performance in Na-ion battery and size-independent performance in metal/H2O seawater battery.
2021, 32(3): 1135-1138
doi: 10.1016/j.cclet.2020.08.043
Abstract:
Doping and increasing specific surface area by forming highly porous structures are two effective ways to enhance the photocatalytic performances of TiO2 particles. Here for the first time, we report a new facile method to prepare the macroporous-mesoporous C-, S-, N-doped TiO2 (C/S/N-TiO2) microspheres via polyHIPE microspheres as templates. The chemical and crystalline structures of these hierarchical porous TiO2 microspheres are analyzed with FTIR, XPS, EDS, and XRD. The macroporous-mesoporous structures are confirmed with SEM observation and BET analysis. UV–vis DRS spectra analysis shows that the band gaps of C doped TiO2, C/N doped TiO2, C/S doped TiO2 and C/S/N doped TiO2 are estimated to be 3.07, 3.01, 2.94 and 2.81 eV, respectively, which are significantly narrower than that of TiO2 nanoparticles (3.23 eV). Photoluminescence spectra demonstrate that the recombination of electrons and holes in these macroporous-mesoporous TiO2 microspheres is also suppressed. The hierarchical porous C/S/N-TiO2 microspheres show high visible-light catalytic efficiency and excellent cycling stability to degrade RhB dye.
Doping and increasing specific surface area by forming highly porous structures are two effective ways to enhance the photocatalytic performances of TiO2 particles. Here for the first time, we report a new facile method to prepare the macroporous-mesoporous C-, S-, N-doped TiO2 (C/S/N-TiO2) microspheres via polyHIPE microspheres as templates. The chemical and crystalline structures of these hierarchical porous TiO2 microspheres are analyzed with FTIR, XPS, EDS, and XRD. The macroporous-mesoporous structures are confirmed with SEM observation and BET analysis. UV–vis DRS spectra analysis shows that the band gaps of C doped TiO2, C/N doped TiO2, C/S doped TiO2 and C/S/N doped TiO2 are estimated to be 3.07, 3.01, 2.94 and 2.81 eV, respectively, which are significantly narrower than that of TiO2 nanoparticles (3.23 eV). Photoluminescence spectra demonstrate that the recombination of electrons and holes in these macroporous-mesoporous TiO2 microspheres is also suppressed. The hierarchical porous C/S/N-TiO2 microspheres show high visible-light catalytic efficiency and excellent cycling stability to degrade RhB dye.
2021, 32(3): 1139-1143
doi: 10.1016/j.cclet.2020.09.008
Abstract:
Stable solid electrolyte interphase (SEI) has been well established to be critical for the reversible operation of Li (ion) batteries, yet our understanding of its mechanical properties currently remains incomplete. Here, we used an electrochemical quartz crystal microbalance combined with dissipation monitoring (EQCM-D) to investigate SEI formation. By quantitatively estimating in-situ, the change in mass, shear modulus, and viscosity of the SEI, we show that the SEI formation in propylene carbonate (PC)- and ethylene carbonate/diethyl carbonate (EC/DEC)-based electrolytes involves the growth of a rigid layer followed by a viscoelastic layer, whereas a distinct "one-layer" rigid model is applicable to the SEI formulated in tetraethylene glycol dimethyl ether (TEGDME)-based electrolyte. With the continuous formation of the SEI, its shear modulus decreases accompanied by an increase in viscosity. In TEGDME, the lightest/thinnest SEI (mass lower than in PC by a factor of nine) yet having the greatest stiffness (more than five times that in PC) is obtained. We attribute this behavior to differences in the chemical composition of the SEIs, which have been revealed by tracking the mass-change-per-mole-of-electron-transferred using EQCM-D and further confirmed by X-ray photoelectron spectroscopy.
Stable solid electrolyte interphase (SEI) has been well established to be critical for the reversible operation of Li (ion) batteries, yet our understanding of its mechanical properties currently remains incomplete. Here, we used an electrochemical quartz crystal microbalance combined with dissipation monitoring (EQCM-D) to investigate SEI formation. By quantitatively estimating in-situ, the change in mass, shear modulus, and viscosity of the SEI, we show that the SEI formation in propylene carbonate (PC)- and ethylene carbonate/diethyl carbonate (EC/DEC)-based electrolytes involves the growth of a rigid layer followed by a viscoelastic layer, whereas a distinct "one-layer" rigid model is applicable to the SEI formulated in tetraethylene glycol dimethyl ether (TEGDME)-based electrolyte. With the continuous formation of the SEI, its shear modulus decreases accompanied by an increase in viscosity. In TEGDME, the lightest/thinnest SEI (mass lower than in PC by a factor of nine) yet having the greatest stiffness (more than five times that in PC) is obtained. We attribute this behavior to differences in the chemical composition of the SEIs, which have been revealed by tracking the mass-change-per-mole-of-electron-transferred using EQCM-D and further confirmed by X-ray photoelectron spectroscopy.
2021, 32(3): 1144-1148
doi: 10.1016/j.cclet.2020.09.006
Abstract:
The development of novel anode materials, with superior rate capability, is of utmost significance for the successful realization of sodium-ion batteries (SIBs). Herein, we present a nanocomposite of Nb2O5 and reduced graphene oxide (rGO) by using hydrothermal-assisted microemulsion route. The water-in-oil microemulsion formed nanoreactors, which restrained the particle size of Nb2O5 and shortened the diffusion length of ions. Moreover, the rGO network prevented agglomeration of Nb2O5 nanoparticles and improved electronic conductivity. Consequently, Nb2O5@rGO nanocomposite is employed as anode material in SIBs, delivering a capacity of 195 mAh/g after 200 charge/discharge cycles at 0.2 A/g. Moreover, owing to conductive rGO network, the Nb2O5@rGO electrode rendered a specific capacity of 76 mAh/g at high current density of 10 A/g and maintained 98 mAh/g after 1000 charge/discharge cycles at 2 A/g. The Nb2O5@rGO electrode material prepared by microemulsion method shows promising possibilities for application of SIBs.
The development of novel anode materials, with superior rate capability, is of utmost significance for the successful realization of sodium-ion batteries (SIBs). Herein, we present a nanocomposite of Nb2O5 and reduced graphene oxide (rGO) by using hydrothermal-assisted microemulsion route. The water-in-oil microemulsion formed nanoreactors, which restrained the particle size of Nb2O5 and shortened the diffusion length of ions. Moreover, the rGO network prevented agglomeration of Nb2O5 nanoparticles and improved electronic conductivity. Consequently, Nb2O5@rGO nanocomposite is employed as anode material in SIBs, delivering a capacity of 195 mAh/g after 200 charge/discharge cycles at 0.2 A/g. Moreover, owing to conductive rGO network, the Nb2O5@rGO electrode rendered a specific capacity of 76 mAh/g at high current density of 10 A/g and maintained 98 mAh/g after 1000 charge/discharge cycles at 2 A/g. The Nb2O5@rGO electrode material prepared by microemulsion method shows promising possibilities for application of SIBs.
2021, 32(3): 1149-1152
doi: 10.1016/j.cclet.2020.09.016
Abstract:
Functional groups in the molecule play an important role in the molecular organization process. To reveal the influence of functional groups on the self-assembly at interface, herein, the self-assembly structures of three liquid crystal molecules, which only differ in the functional groups, are explicitly characterized by using scanning tunneling microscopy (STM). The high-resolution STM images demonstrate the difference between the supramolecular assembly structures of three liquid crystal molecules, which attribute to the hydrogen bonding interaction and π-π stacking interaction between different functional groups. The density functional theory (DFT) results also confirm the influence of these functional groups on the self-assemblies. The effort on the self-assembly of liquid crystal molecules at interface could enhance the understanding of the supramolecular assembly mechanism and benefit the further application of liquid crystals.
Functional groups in the molecule play an important role in the molecular organization process. To reveal the influence of functional groups on the self-assembly at interface, herein, the self-assembly structures of three liquid crystal molecules, which only differ in the functional groups, are explicitly characterized by using scanning tunneling microscopy (STM). The high-resolution STM images demonstrate the difference between the supramolecular assembly structures of three liquid crystal molecules, which attribute to the hydrogen bonding interaction and π-π stacking interaction between different functional groups. The density functional theory (DFT) results also confirm the influence of these functional groups on the self-assemblies. The effort on the self-assembly of liquid crystal molecules at interface could enhance the understanding of the supramolecular assembly mechanism and benefit the further application of liquid crystals.
2021, 32(3): 1153-1156
doi: 10.1016/j.cclet.2020.09.014
Abstract:
Selective separation of CO2/CH4 and C2H2/CH4 are promising for their high-purity industrial demand and scientific research on account of the similar molecular radius and physical properties. In this work, a unique 3D microporous MOF material [Cu(SiF6)(sdi)2] solvents (1, sdi = 1, 1'-sulfonyldiimidazole) was successfully constructed by cross-linking 1D coordination polymer chains. The dense functional active sites on the inner walls of the channel of 1a can provide strong binding affinities to CO2, C2H2, and thus effectively improve the gas separation performance of CO2/CH4 and C2H2/CH4.
Selective separation of CO2/CH4 and C2H2/CH4 are promising for their high-purity industrial demand and scientific research on account of the similar molecular radius and physical properties. In this work, a unique 3D microporous MOF material [Cu(SiF6)(sdi)2] solvents (1, sdi = 1, 1'-sulfonyldiimidazole) was successfully constructed by cross-linking 1D coordination polymer chains. The dense functional active sites on the inner walls of the channel of 1a can provide strong binding affinities to CO2, C2H2, and thus effectively improve the gas separation performance of CO2/CH4 and C2H2/CH4.
2021, 32(3): 1157-1160
doi: 10.1016/j.cclet.2020.09.022
Abstract:
Lithium sulfur batteries with high energy density are thought to be the most potential energy storage technology that can be commercialized. However, the shuttle effect of polysulfides deteriorates its electrochemical performance. Herein, a novel Co9S8 nanostructure derived from metal organic framework material (MOF) was explored by simple liquid phase reaction and heat vulcanization of 2-methylimidazole and Co(NO3)2·6H2O on the surface of the original PP separator. The Co9S8 nano-flower cluster array wall was vertically and closely arranged with the thickness of 200 nm, and the polysulfide can be adsorbed by its physical and chemical action to slow down the "shuttle effect". It is found that the cell with the modified separator can achieve an ideal discharge capacity of about 600 mAh/g at 1 C. The specific capacity is maintained at 500 mAh/g after 200 cycles, with only 0.11% of capacity decay per cycle. It provides a new way for the utilization of MOF material derivatives to modify the separator in order to improve the electrochemical performance of lithium-sulfur batteries.
Lithium sulfur batteries with high energy density are thought to be the most potential energy storage technology that can be commercialized. However, the shuttle effect of polysulfides deteriorates its electrochemical performance. Herein, a novel Co9S8 nanostructure derived from metal organic framework material (MOF) was explored by simple liquid phase reaction and heat vulcanization of 2-methylimidazole and Co(NO3)2·6H2O on the surface of the original PP separator. The Co9S8 nano-flower cluster array wall was vertically and closely arranged with the thickness of 200 nm, and the polysulfide can be adsorbed by its physical and chemical action to slow down the "shuttle effect". It is found that the cell with the modified separator can achieve an ideal discharge capacity of about 600 mAh/g at 1 C. The specific capacity is maintained at 500 mAh/g after 200 cycles, with only 0.11% of capacity decay per cycle. It provides a new way for the utilization of MOF material derivatives to modify the separator in order to improve the electrochemical performance of lithium-sulfur batteries.
2021, 32(3): 1161-1164
doi: 10.1016/j.cclet.2020.09.025
Abstract:
Potassium-ion batteries (PIBs) are attracted tremendous interest for large-scale energy storage systems (ESSs) owing to their economic merits. However, the main challenges of the PIBs are sluggish K-ion diffusion and large volume variations in the potassium repeated intercalation/deintercalation. Herein, mesoporous carbon nanosheet-assembled flowers (abbreviated as F-C) are designed as an original anode for superior-performance PIBs. Specifically, the F-C anode exhibits a high K-storage capacity (e.g., 381 mAh/g at 50 mA/g during the 2nd cycle), excellent rate performance (e.g., 101 mAh/g at 2.0 A/g) and superior long cycle capability. Such excellent K-ion storage property is largely benefited from the large surface area (~141 m2/g) and reasonable pore volume (0.465 cm3/g), which not only stimulates rapid K-ions diffusion and relieves the huge volume strain, but also exposes extensive active sites for K-ion capacitive storage.
Potassium-ion batteries (PIBs) are attracted tremendous interest for large-scale energy storage systems (ESSs) owing to their economic merits. However, the main challenges of the PIBs are sluggish K-ion diffusion and large volume variations in the potassium repeated intercalation/deintercalation. Herein, mesoporous carbon nanosheet-assembled flowers (abbreviated as F-C) are designed as an original anode for superior-performance PIBs. Specifically, the F-C anode exhibits a high K-storage capacity (e.g., 381 mAh/g at 50 mA/g during the 2nd cycle), excellent rate performance (e.g., 101 mAh/g at 2.0 A/g) and superior long cycle capability. Such excellent K-ion storage property is largely benefited from the large surface area (~141 m2/g) and reasonable pore volume (0.465 cm3/g), which not only stimulates rapid K-ions diffusion and relieves the huge volume strain, but also exposes extensive active sites for K-ion capacitive storage.
2021, 32(3): 1165-1168
doi: 10.1016/j.cclet.2020.09.037
Abstract:
Photoelectrochemical (PEC) water splitting is a promising approach for renewable hydrogen production. However, the practical PEC solar-to-fuel conversion efficiency is still low owing to poor light absorption and rapid recombination of charge carriers in photoelectrode. In this work, we report a ternary photoanode with simultaneously enhancement of light absorption and water oxidation efficiency by introducing copper phthalocyanine (CuPc) and nickel iron-layered double hydroxide (NiFe-LDH) on TiO2 (denoted as TiO2/CuPc/NiFe-LDH). An experimental study reveals that CuPc loading on TiO2 bring strong visible light absorption; NiFe-LDH as an oxygen evolution reaction catalyst efficiently accelerates the surface water oxidation reaction. This synergistic effect of CuPc and NiFe-LDH gives enhanced photocurrent density (2.10 mA/cm2 at 0.6 V vs. SCE) and excellent stability in the ternary TiO2/CuPc/NiFeLDH photoanode.
Photoelectrochemical (PEC) water splitting is a promising approach for renewable hydrogen production. However, the practical PEC solar-to-fuel conversion efficiency is still low owing to poor light absorption and rapid recombination of charge carriers in photoelectrode. In this work, we report a ternary photoanode with simultaneously enhancement of light absorption and water oxidation efficiency by introducing copper phthalocyanine (CuPc) and nickel iron-layered double hydroxide (NiFe-LDH) on TiO2 (denoted as TiO2/CuPc/NiFe-LDH). An experimental study reveals that CuPc loading on TiO2 bring strong visible light absorption; NiFe-LDH as an oxygen evolution reaction catalyst efficiently accelerates the surface water oxidation reaction. This synergistic effect of CuPc and NiFe-LDH gives enhanced photocurrent density (2.10 mA/cm2 at 0.6 V vs. SCE) and excellent stability in the ternary TiO2/CuPc/NiFeLDH photoanode.
2021, 32(3): 1169-1172
doi: 10.1016/j.cclet.2020.09.036
Abstract:
An unexpected in-situ hydrolysis reaction occurred during the solvothermal reaction of N, N'-bis(4-carboxy-2-methylphenyl)pyromellitic di-imide) and Ba(NO3)2, and a novel porous Ba-MOF, [H2N(CH3)2]0.5[Ba1.5(L)(DMA)]·1.5DMA·1.5H2O (UPC-70, H3L = 2-(4-carboxy-2-methylphenyl)-1, 3-dioxoisoin-doline-5, 6-dicarboxylic acid, DMA = N, N-dimethylacetamide), was obtained on the basis of the partial hydrolysate. The as-synthesized 3D network with 1D open channels of different sizes (24 Å and 10 Å) contains abundant open metal sites after removal of solvents, which is conducive to the preferential adsorption of CO2. The subsequent gas sorption measurement reveals the high separation selectivity of UPC-70 for CO2/CH4 (15) and CO2/N2 (32) at ambient conditions, and GCMC theoretical simulation provides good verification of the experimental results, indicating that UPC-70 is a potential candidate for CO2 capture from flue gas and natural gas.
An unexpected in-situ hydrolysis reaction occurred during the solvothermal reaction of N, N'-bis(4-carboxy-2-methylphenyl)pyromellitic di-imide) and Ba(NO3)2, and a novel porous Ba-MOF, [H2N(CH3)2]0.5[Ba1.5(L)(DMA)]·1.5DMA·1.5H2O (UPC-70, H3L = 2-(4-carboxy-2-methylphenyl)-1, 3-dioxoisoin-doline-5, 6-dicarboxylic acid, DMA = N, N-dimethylacetamide), was obtained on the basis of the partial hydrolysate. The as-synthesized 3D network with 1D open channels of different sizes (24 Å and 10 Å) contains abundant open metal sites after removal of solvents, which is conducive to the preferential adsorption of CO2. The subsequent gas sorption measurement reveals the high separation selectivity of UPC-70 for CO2/CH4 (15) and CO2/N2 (32) at ambient conditions, and GCMC theoretical simulation provides good verification of the experimental results, indicating that UPC-70 is a potential candidate for CO2 capture from flue gas and natural gas.
2021, 32(3): 1173-1176
doi: 10.1016/j.cclet.2020.07.037
Abstract:
Three novel polycyclic polyprenyled acylphloroglucinols, Hyperscabins A-C, were obtained from the aerial parts of Hypericum scabrum. They featured an unprecedented 5, 5-spiroketal subunit with the loss of C-2' carbonyl in the phloroglucinol ring. Their structures were characterized by extensive spectroscopic analyses, NMR calculations with DP4+ analysis, calculated electronic circular dichroism (ECD) spectra and the application of modified Mosher's methods. In the assay of [3H]-5-HT and [3H]-NE reuptake inhibition, compounds 1 and 2 showed good inhibitory activity (81.8% and 83.2%) in 10 μmol/L. In addition, compound 1 significantly increased cell viability in the experiment of oxygen and glucose deprivation/deoxygenation.
Three novel polycyclic polyprenyled acylphloroglucinols, Hyperscabins A-C, were obtained from the aerial parts of Hypericum scabrum. They featured an unprecedented 5, 5-spiroketal subunit with the loss of C-2' carbonyl in the phloroglucinol ring. Their structures were characterized by extensive spectroscopic analyses, NMR calculations with DP4+ analysis, calculated electronic circular dichroism (ECD) spectra and the application of modified Mosher's methods. In the assay of [3H]-5-HT and [3H]-NE reuptake inhibition, compounds 1 and 2 showed good inhibitory activity (81.8% and 83.2%) in 10 μmol/L. In addition, compound 1 significantly increased cell viability in the experiment of oxygen and glucose deprivation/deoxygenation.
2021, 32(3): 1177-1180
doi: 10.1016/j.cclet.2020.09.002
Abstract:
The development of a practical synthetic method to functionalize hollow mesoporous silica with organic groups is of current interest for selective adsorption and energy storage applications. Herein, a facile and controllable one-pot approach for the synthesis of monodisperse amino-functionalized hollow mesoporous silica nanoparticles is presented. A novel solid-to-hollow structural transformation procedure of the silica nanoparticles is presented. The structural transformation is easily designed, as observed through transmission electron microscopy, by tailoring the HCl and N-lauroylsarcosine sodium molar ratio and the water content in the sol-gel. Ordered and radially oriented in situ amino-functionalized mesochannels were successfully introduced into the shells of the hollow silica nanoparticles. A formation mechanism for the hollow mesoporous silica materials is discussed.
The development of a practical synthetic method to functionalize hollow mesoporous silica with organic groups is of current interest for selective adsorption and energy storage applications. Herein, a facile and controllable one-pot approach for the synthesis of monodisperse amino-functionalized hollow mesoporous silica nanoparticles is presented. A novel solid-to-hollow structural transformation procedure of the silica nanoparticles is presented. The structural transformation is easily designed, as observed through transmission electron microscopy, by tailoring the HCl and N-lauroylsarcosine sodium molar ratio and the water content in the sol-gel. Ordered and radially oriented in situ amino-functionalized mesochannels were successfully introduced into the shells of the hollow silica nanoparticles. A formation mechanism for the hollow mesoporous silica materials is discussed.
2021, 32(3): 1181-1185
doi: 10.1016/j.cclet.2020.07.045
Abstract:
Non-enzymatic electrochemical sensors for the determination of hydrogen peroxide (H2O2) have attracted more and more concerns. A series of nickel and cobalt double oxides (NixCoy-DO) with the different ratios of Ni/Co have been prepared by a polyol-mediated solvothermal method for H2O2 detection. The obtained products exhibit honeycomb-like open porous microtubes constituted with the low-dimensional nanostructured NixCoy-DO blocks after the calcination treatment. Compared with nickel oxides, the introduced Co ions in NixCoy-DO can induce the production of surficial oxygen vacancies, and further enhance the electrode surface activity. In particular, the NiCo-DO sample (with an atomic ratio of Ni/Co = 4:3) shows the richest surficial oxygen vacancies and presents the highest H2O2 detection activity among all the as-prepared samples, demonstrating an excellent sensitivity of 698.60 μA L mmol-1 cm-2 (0 ~ 0.4 mmol/L), low detection limit (0.28 μmol/L, S/N = 3), as well as long stability, high selectivity and good reproducibility. This work lends a new impetus to the potential application of double metal oxides for the next generation of non-enzymatic sensors.
Non-enzymatic electrochemical sensors for the determination of hydrogen peroxide (H2O2) have attracted more and more concerns. A series of nickel and cobalt double oxides (NixCoy-DO) with the different ratios of Ni/Co have been prepared by a polyol-mediated solvothermal method for H2O2 detection. The obtained products exhibit honeycomb-like open porous microtubes constituted with the low-dimensional nanostructured NixCoy-DO blocks after the calcination treatment. Compared with nickel oxides, the introduced Co ions in NixCoy-DO can induce the production of surficial oxygen vacancies, and further enhance the electrode surface activity. In particular, the NiCo-DO sample (with an atomic ratio of Ni/Co = 4:3) shows the richest surficial oxygen vacancies and presents the highest H2O2 detection activity among all the as-prepared samples, demonstrating an excellent sensitivity of 698.60 μA L mmol-1 cm-2 (0 ~ 0.4 mmol/L), low detection limit (0.28 μmol/L, S/N = 3), as well as long stability, high selectivity and good reproducibility. This work lends a new impetus to the potential application of double metal oxides for the next generation of non-enzymatic sensors.
2021, 32(3): 1186-1190
doi: 10.1016/j.cclet.2020.07.044
Abstract:
Catalytic transfer hydrogenation (CTH) of furfural (FF) to furfuryl alcohol (FFA) has received great interest in recent years. Herein, Cu-Cs bimetallic supported catalyst, CuCs(2)-MCM, was developed for the CTH of FF to FFA using formic as hydrogen donor. CuCs(2)-MCM achieved a 99.6% FFA yield at an optimized reaction conditions of 170 ℃, 1 h. Cu species in CuCs(2)-MCM had dual functions in catalytically decomposing formic acid to generate hydrogen and hydrogenating FF to FFA. The doping of Cs made the size of Cu particles smaller and improved the dispersion of the Cu active sites. Importantly, the Cs species played a favorable role in enhancing the hydrogenation activity as a promoter by adjusting the surface acidity of Cu species to an appropriate level. Correlation analysis showed that surface acidity is the primary factor to affect the catalytic activity of CuCs(2)-MCM.
Catalytic transfer hydrogenation (CTH) of furfural (FF) to furfuryl alcohol (FFA) has received great interest in recent years. Herein, Cu-Cs bimetallic supported catalyst, CuCs(2)-MCM, was developed for the CTH of FF to FFA using formic as hydrogen donor. CuCs(2)-MCM achieved a 99.6% FFA yield at an optimized reaction conditions of 170 ℃, 1 h. Cu species in CuCs(2)-MCM had dual functions in catalytically decomposing formic acid to generate hydrogen and hydrogenating FF to FFA. The doping of Cs made the size of Cu particles smaller and improved the dispersion of the Cu active sites. Importantly, the Cs species played a favorable role in enhancing the hydrogenation activity as a promoter by adjusting the surface acidity of Cu species to an appropriate level. Correlation analysis showed that surface acidity is the primary factor to affect the catalytic activity of CuCs(2)-MCM.
2021, 32(3): 1191-1196
doi: 10.1016/j.cclet.2020.08.005
Abstract:
MoS2 has emerged for catalyzing the hydrogen evolution reaction. Various notable strategies have been developed to downsize the MoS2 particles and expose more active edges. However, the restacking issue, which reduces the exposure degree, has rarely been taken into account. Herein, we report on a facile proton-induced fast hydrothermal approach to produce size-controllable MoS2 nanocatalysts and demonstrate that along the varying of sheet sizes, there is a trade-off between the intrinsic catalytic activity (mainly determined by the unsaturated sulfur on the sheet edges) and the active edge accessibility (influenced by the assembly structure). The size-optimized catalyst delivers a high performance of a low overpotential of ~200 mV at 10 mA/cm2, a Tafel slope of 46.3 mV/dec, and a stable working state, which is comparable to the recent notable works. Our findings will provide a pathway for its large-scale application and enhance the water electrolysis performance.
MoS2 has emerged for catalyzing the hydrogen evolution reaction. Various notable strategies have been developed to downsize the MoS2 particles and expose more active edges. However, the restacking issue, which reduces the exposure degree, has rarely been taken into account. Herein, we report on a facile proton-induced fast hydrothermal approach to produce size-controllable MoS2 nanocatalysts and demonstrate that along the varying of sheet sizes, there is a trade-off between the intrinsic catalytic activity (mainly determined by the unsaturated sulfur on the sheet edges) and the active edge accessibility (influenced by the assembly structure). The size-optimized catalyst delivers a high performance of a low overpotential of ~200 mV at 10 mA/cm2, a Tafel slope of 46.3 mV/dec, and a stable working state, which is comparable to the recent notable works. Our findings will provide a pathway for its large-scale application and enhance the water electrolysis performance.
2021, 32(3): 1197-1201
doi: 10.1016/j.cclet.2020.08.049
Abstract:
Radiotherapy is commonly used to treat advanced pancreatic cancers and can improve survival by 2 months in combination with gemcitabine. However, prognosis and survival improvement remain unsatisfactory, and effective therapies are urgently needed. Piperlongumine has been demonstrated to have therapeutic potentials against various cancers. In this study, we synthesized a series of piperlongumine derivatives and provided evidence that piperlongumine derivatives could be used as effective radiosensitizers in pancreatic cancer. Two compounds enhanced the radiosensitivity of Panc-1 and SW1990 cells. In a pancreatic bi-flank xenograft tumor model, they significantly inhibited tumor growth. Piperlongumine derivatives could induce reactive oxygen species (ROS) expression and regulate the Keap1-Nrf2 protective pathway with enhancement of radiation-induced DNA damage, G2/M-phase cell cycle arrest, and apoptosis. Collectively, our data offer a proof of concept for the use of piperlongumine derivatives as a novel class of radiosensitizers for the treatment of pancreatic cancer.
Radiotherapy is commonly used to treat advanced pancreatic cancers and can improve survival by 2 months in combination with gemcitabine. However, prognosis and survival improvement remain unsatisfactory, and effective therapies are urgently needed. Piperlongumine has been demonstrated to have therapeutic potentials against various cancers. In this study, we synthesized a series of piperlongumine derivatives and provided evidence that piperlongumine derivatives could be used as effective radiosensitizers in pancreatic cancer. Two compounds enhanced the radiosensitivity of Panc-1 and SW1990 cells. In a pancreatic bi-flank xenograft tumor model, they significantly inhibited tumor growth. Piperlongumine derivatives could induce reactive oxygen species (ROS) expression and regulate the Keap1-Nrf2 protective pathway with enhancement of radiation-induced DNA damage, G2/M-phase cell cycle arrest, and apoptosis. Collectively, our data offer a proof of concept for the use of piperlongumine derivatives as a novel class of radiosensitizers for the treatment of pancreatic cancer.
2021, 32(3): 1202-1205
doi: 10.1016/j.cclet.2020.08.050
Abstract:
Tsaokols A (1) and B (2), two complicated flavanol-monoterpenoid hybrids, were isolated from the dried fruits of Amomum tsao-ko under the guidance of LCMS and bioassay. Their structures were determined by extensive spectroscopic analyses and electronic circular dichroism (ECD) calculations. Compounds 1 and 2 shared a flavanol backbone fused with 5/7 and 5/6 bicyclic monoterpenoid scaffolds, which were biogenetically condensed by Michael addition and acetalization. Compounds 1 and 2 exhibited significant α-glucosidase inhibitory activity with IC50 values of 18.8 and 38.6 μmol/L (acarbose, IC50 = 213 μmol/L). Docking study supported the strong interactions of 1 and 2 bonding with enzyme by mainly hydrophobic and hydrogen-bond effects. Compounds 1 and 2 could be fast distinguished by the diagnostic ions at m/z 289 and 313 in negative MS2 experiments.
Tsaokols A (1) and B (2), two complicated flavanol-monoterpenoid hybrids, were isolated from the dried fruits of Amomum tsao-ko under the guidance of LCMS and bioassay. Their structures were determined by extensive spectroscopic analyses and electronic circular dichroism (ECD) calculations. Compounds 1 and 2 shared a flavanol backbone fused with 5/7 and 5/6 bicyclic monoterpenoid scaffolds, which were biogenetically condensed by Michael addition and acetalization. Compounds 1 and 2 exhibited significant α-glucosidase inhibitory activity with IC50 values of 18.8 and 38.6 μmol/L (acarbose, IC50 = 213 μmol/L). Docking study supported the strong interactions of 1 and 2 bonding with enzyme by mainly hydrophobic and hydrogen-bond effects. Compounds 1 and 2 could be fast distinguished by the diagnostic ions at m/z 289 and 313 in negative MS2 experiments.
2021, 32(3): 1206-1209
doi: 10.1016/j.cclet.2020.09.001
Abstract:
To date, investigations onto the regulation of reactants mass transfer has been paid much less attention in environmental catalysis. Herein, we demonstrated that by rationally designing the adsorption sites of multi-reactants, the pollutant destruction efficiency, product selectivity, reaction stability and secondary pollution have been all affected in the catalytic chlorobenzene oxidation (CBCO). Experimental results revealed that the co-adsorption of chlorobenzene (CB) and gaseous O2 at the oxygen vacancies of CeO2 led to remarkably high CO2 generation, owning to their short mass transfer distance on the catalyst surface, while their separated adsorptions at Brönsted HZSM-5 and CeO2 vacancies resulted in a much lower CO2 generation, and produced significant polychlorinated byproducts in the off-gas. However, this separated adsorption model yielded superior long-term stability for the CeO2/HZSM-5 catalyst, owning to the protection of CeO2 oxygen vacancies from Cl poisoning by the preferential adsorption of CB on the Brönsted acidic sites. This work unveils that design of environmental catalysts needs to consider both of the catalyst intrinsic property and reactant mass transfer; investigations of the latter could pave a new way for the development of highly efficient catalysts towards environmental pollution control.
To date, investigations onto the regulation of reactants mass transfer has been paid much less attention in environmental catalysis. Herein, we demonstrated that by rationally designing the adsorption sites of multi-reactants, the pollutant destruction efficiency, product selectivity, reaction stability and secondary pollution have been all affected in the catalytic chlorobenzene oxidation (CBCO). Experimental results revealed that the co-adsorption of chlorobenzene (CB) and gaseous O2 at the oxygen vacancies of CeO2 led to remarkably high CO2 generation, owning to their short mass transfer distance on the catalyst surface, while their separated adsorptions at Brönsted HZSM-5 and CeO2 vacancies resulted in a much lower CO2 generation, and produced significant polychlorinated byproducts in the off-gas. However, this separated adsorption model yielded superior long-term stability for the CeO2/HZSM-5 catalyst, owning to the protection of CeO2 oxygen vacancies from Cl poisoning by the preferential adsorption of CB on the Brönsted acidic sites. This work unveils that design of environmental catalysts needs to consider both of the catalyst intrinsic property and reactant mass transfer; investigations of the latter could pave a new way for the development of highly efficient catalysts towards environmental pollution control.
2021, 32(3): 1210-1214
doi: 10.1016/j.cclet.2020.09.030
Abstract:
Developing highly efficient nickel or iron based hydroxide electrocatalysts is primary essential but challenging for oxygen evolution reaction (OER) at ultra-high current densities. Herein, we developed a facile method to prepare nitrogen and iron doped nickel(Ⅱ) hydroxide nanosheets on self-supported conductive nickel foam (denoted as Fe, N-Ni(OH)2/NF) through ammonia hydrothermal and impregnation methods. Owing to the optimization of the electronic structure by nitrogen doping and the strong synergistic effect between Fe and Ni(OH)2, the three-dimensional (3D) Fe, N-Ni(OH)2/NF nanosheets delivered superior electrocatalytic OER performances in basic solution with low potentials of 1.57V and 1.59V under 500mA/cm2 and 1000mA/cm2 respectively and robust operation for 10 h with ignored activity decay, comparing well with the potentials of previously reported NiFe based electrocatalysts as well as the benchmark commercial Ir/C/NF. In-situ Raman spectroscopy revealed that the main active species were NiOOH during the OER process. The present results are expected to provide new insights into the study of OER process towards ultra-high current densities.
Developing highly efficient nickel or iron based hydroxide electrocatalysts is primary essential but challenging for oxygen evolution reaction (OER) at ultra-high current densities. Herein, we developed a facile method to prepare nitrogen and iron doped nickel(Ⅱ) hydroxide nanosheets on self-supported conductive nickel foam (denoted as Fe, N-Ni(OH)2/NF) through ammonia hydrothermal and impregnation methods. Owing to the optimization of the electronic structure by nitrogen doping and the strong synergistic effect between Fe and Ni(OH)2, the three-dimensional (3D) Fe, N-Ni(OH)2/NF nanosheets delivered superior electrocatalytic OER performances in basic solution with low potentials of 1.57V and 1.59V under 500mA/cm2 and 1000mA/cm2 respectively and robust operation for 10 h with ignored activity decay, comparing well with the potentials of previously reported NiFe based electrocatalysts as well as the benchmark commercial Ir/C/NF. In-situ Raman spectroscopy revealed that the main active species were NiOOH during the OER process. The present results are expected to provide new insights into the study of OER process towards ultra-high current densities.
2021, 32(3): 1215-1219
doi: 10.1016/j.cclet.2020.09.013
Abstract:
A multifunctional nanocomposite of AgNPs@GQDs is prepared by synergistic in-situ growth of silver nanoparticles (AgNPs) on the complex of tannic acid (TA) and graphene quantum dots (GQDs) for the construction of dual-mode biosensing platform and cancer theranostics. The nanocomposite exhibits a hydrogen peroxide (H2O2)-responsive degradation, in which Ag0 is oxidized to Ag+ along with the release of oxidized TA and GQDs. The degradation induces the decreased absorbance and enhanced fluorescence (FL) intensity due to the suppression of Förster resonance energy transfer (FRET) in AgNPs@GQDs, which is employed for colorimetric/fluorescence dual-mode sensing of H2O2. The intrinsic peroxidase-like activity of GQDs nanozyme can effectively catalyze the oxidation reaction, enhancing the detection sensitivity significantly. Based on the generation of H2O2 from the oxidation of glucose with the catalysis of glucose oxidase (GOx), this nanoprobe is versatilely used for the determination of glucose in human serum. Further, through combining the H2O2-responsive degradation of AgNPs@GQDs with high H2O2 level in cancer cells, the nanocomposites exhibit good performance in cancer cell recognition and therapy, in which the synergistic anticancer effect of Ag+ and oxidized TA contribute to effective cell death, and the liberated GQDs are used to monitor the therapeutic effect by cell imaging.
A multifunctional nanocomposite of AgNPs@GQDs is prepared by synergistic in-situ growth of silver nanoparticles (AgNPs) on the complex of tannic acid (TA) and graphene quantum dots (GQDs) for the construction of dual-mode biosensing platform and cancer theranostics. The nanocomposite exhibits a hydrogen peroxide (H2O2)-responsive degradation, in which Ag0 is oxidized to Ag+ along with the release of oxidized TA and GQDs. The degradation induces the decreased absorbance and enhanced fluorescence (FL) intensity due to the suppression of Förster resonance energy transfer (FRET) in AgNPs@GQDs, which is employed for colorimetric/fluorescence dual-mode sensing of H2O2. The intrinsic peroxidase-like activity of GQDs nanozyme can effectively catalyze the oxidation reaction, enhancing the detection sensitivity significantly. Based on the generation of H2O2 from the oxidation of glucose with the catalysis of glucose oxidase (GOx), this nanoprobe is versatilely used for the determination of glucose in human serum. Further, through combining the H2O2-responsive degradation of AgNPs@GQDs with high H2O2 level in cancer cells, the nanocomposites exhibit good performance in cancer cell recognition and therapy, in which the synergistic anticancer effect of Ag+ and oxidized TA contribute to effective cell death, and the liberated GQDs are used to monitor the therapeutic effect by cell imaging.
2021, 32(3): 1220-1223
doi: 10.1016/j.cclet.2020.09.003
Abstract:
In this study, we prepared mitochondrion targeting peptide-grafted magnetic graphene oxide (GO) nanocarriers for efficient impairment of the tumor mitochondria. The two-dimensional GOMNP-MitP nanosheets were synthesized by grafting magnetic γ-Fe2O3 to the surface of GO, followed by covalent modification of mitochondrion targeting peptide (MitP). GOMNP-MitP exhibited the high capacity of loading the anticancer drug mitoxantrone (MTX), and preferentially targeted the tumor mitochondria. With the aid of alternating magnetic field (AMF), the MTX-loading GOMNP-MitP released MTX to the mitochondria, severely impairing mitochondrial functions, including attenuation of ATP production, decrease in mitochondrial membrane potential (MMP), and further leading to activation of apoptosis. This study realized high-efficient mitochondrion-targeting drug delivery for anticancer therapy by two-dimensional nanoplatforms.
In this study, we prepared mitochondrion targeting peptide-grafted magnetic graphene oxide (GO) nanocarriers for efficient impairment of the tumor mitochondria. The two-dimensional GOMNP-MitP nanosheets were synthesized by grafting magnetic γ-Fe2O3 to the surface of GO, followed by covalent modification of mitochondrion targeting peptide (MitP). GOMNP-MitP exhibited the high capacity of loading the anticancer drug mitoxantrone (MTX), and preferentially targeted the tumor mitochondria. With the aid of alternating magnetic field (AMF), the MTX-loading GOMNP-MitP released MTX to the mitochondria, severely impairing mitochondrial functions, including attenuation of ATP production, decrease in mitochondrial membrane potential (MMP), and further leading to activation of apoptosis. This study realized high-efficient mitochondrion-targeting drug delivery for anticancer therapy by two-dimensional nanoplatforms.
2021, 32(3): 1224-1228
doi: 10.1016/j.cclet.2020.09.031
Abstract:
In this work, various Co3O4-ZSM-5 catalysts were prepared by the microwave hydrothermal method (MH-Co3O4@ZSM-5), dynamic hydrothermal method (DH-Co3O4@ZSM-5), and conventional hydrothermal method (CH-Co3O4/ZSM-5). Their catalytic oxidation of dichloromethane (DCM) was analyzed. Detailed characterizations such as X-ray diffractometer (XRD), scanning microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET), H2 temperature-programmed reduction (H2-TPR), temperature-programmed desorption of O2 (O2-TPD), temperature-programmed desorption of NH3 (NH3-TPD), diffuse reflectance infrared Fourier-transform spectra with NH3 molecules (NH3-DRIFT), and temperature-programmed surface reaction (TPSR) were performed. Results showed that with the assistance of microwave, MH-Co3O4@ZSM-5 formed a uniform core-shell structure, while the other two samples did not. MH-Co3O4@ZSM-5 possessed rich surface adsorbed oxygen species, higher ratio of Co3+/Co2+, strong acidity, high reducibility, and oxygen mobility among the three Co3O4-ZSM-5 catalysts, which was beneficial for the improvement of DCM oxidation. In the oxidation of dichloromethane, MH-Co3O4@ZSM-5 presented the best activity and mineralization, which was consistent with the characterizations results. Meanwhile, according to the TPSR test, HCl or Cl2 removal from the catalyst surface was also promoted in MH-Co3O4@ZSM-5 by their abundant Brønsted acid sites and the promotion of Deacon reaction by Co3O4 or the synergistic effect of Co3O4 and ZSM-5. According to the results of in situ DRIFT studies, a possible reaction pathway of DCM oxidation was proposed over the MH-Co3O4@ZSM-5 catalysts.
In this work, various Co3O4-ZSM-5 catalysts were prepared by the microwave hydrothermal method (MH-Co3O4@ZSM-5), dynamic hydrothermal method (DH-Co3O4@ZSM-5), and conventional hydrothermal method (CH-Co3O4/ZSM-5). Their catalytic oxidation of dichloromethane (DCM) was analyzed. Detailed characterizations such as X-ray diffractometer (XRD), scanning microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET), H2 temperature-programmed reduction (H2-TPR), temperature-programmed desorption of O2 (O2-TPD), temperature-programmed desorption of NH3 (NH3-TPD), diffuse reflectance infrared Fourier-transform spectra with NH3 molecules (NH3-DRIFT), and temperature-programmed surface reaction (TPSR) were performed. Results showed that with the assistance of microwave, MH-Co3O4@ZSM-5 formed a uniform core-shell structure, while the other two samples did not. MH-Co3O4@ZSM-5 possessed rich surface adsorbed oxygen species, higher ratio of Co3+/Co2+, strong acidity, high reducibility, and oxygen mobility among the three Co3O4-ZSM-5 catalysts, which was beneficial for the improvement of DCM oxidation. In the oxidation of dichloromethane, MH-Co3O4@ZSM-5 presented the best activity and mineralization, which was consistent with the characterizations results. Meanwhile, according to the TPSR test, HCl or Cl2 removal from the catalyst surface was also promoted in MH-Co3O4@ZSM-5 by their abundant Brønsted acid sites and the promotion of Deacon reaction by Co3O4 or the synergistic effect of Co3O4 and ZSM-5. According to the results of in situ DRIFT studies, a possible reaction pathway of DCM oxidation was proposed over the MH-Co3O4@ZSM-5 catalysts.
2021, 32(3): 1229-1232
doi: 10.1016/j.cclet.2020.08.013
Abstract:
A simple and efficient visible-light-induced photoredox-catalyzed diarylation of N-methacryloyl-2-arylbenzoimidazoles with aryl diazonium salts was developed. The reaction provides a convenient access to a variety of benzimidazoisoquinolinones through the construction of two CC bonds in one step under mild reaction conditions.
A simple and efficient visible-light-induced photoredox-catalyzed diarylation of N-methacryloyl-2-arylbenzoimidazoles with aryl diazonium salts was developed. The reaction provides a convenient access to a variety of benzimidazoisoquinolinones through the construction of two CC bonds in one step under mild reaction conditions.
2021, 32(3): 1233-1236
doi: 10.1016/j.cclet.2020.08.028
Abstract:
High-mobility and strong luminescent materials are essential as an important component of organic photodiodes, having received extensive attention in the field of organic optoelectronics. Beyond the conventional chemical synthesis of new molecules, pressure technology, as a flexible and efficient method, can tune the electronic and optical properties reversibly. However, the mechanism in organic materials has not been systematically revealed. Here, we theoretically predicted the pressure-depended luminescence and charge transport properties of high-performance organic optoelectronic semiconductors, 2, 6-diphenylanthracene (DPA), by first-principle and multi-scale theoretical calculation methods. The dispersion-corrected density functional theory (DFT-D) and hybrid quantum mechanics/molecular mechanics (QM/MM) method were used to get the electronic structures and vibration properties under pressure. Furthermore, the charge transport and luminescence properties were calculated with the quantum tunneling method and thermal vibration correlation function. We found that the pressure could significantly improve the charge transport performance of the DPA single crystal. When the applied pressure increased to 1.86GPa, the hole mobility could be doubled. At the same time, due to the weak exciton coupling effect and the rigid flat structure, there is neither fluorescence quenching nor obvious emission enhancement phenomenon. The DPA single crystal possesses a slightly higher fluorescence quantum yield ~ 0.47 under pressure. Our work systematically explored the pressure-dependence photoelectric properties and explained the inside mechanism. Also, we proposed that the external pressure would be an effective way to improve the photoelectric performance of organic semiconductors.
High-mobility and strong luminescent materials are essential as an important component of organic photodiodes, having received extensive attention in the field of organic optoelectronics. Beyond the conventional chemical synthesis of new molecules, pressure technology, as a flexible and efficient method, can tune the electronic and optical properties reversibly. However, the mechanism in organic materials has not been systematically revealed. Here, we theoretically predicted the pressure-depended luminescence and charge transport properties of high-performance organic optoelectronic semiconductors, 2, 6-diphenylanthracene (DPA), by first-principle and multi-scale theoretical calculation methods. The dispersion-corrected density functional theory (DFT-D) and hybrid quantum mechanics/molecular mechanics (QM/MM) method were used to get the electronic structures and vibration properties under pressure. Furthermore, the charge transport and luminescence properties were calculated with the quantum tunneling method and thermal vibration correlation function. We found that the pressure could significantly improve the charge transport performance of the DPA single crystal. When the applied pressure increased to 1.86GPa, the hole mobility could be doubled. At the same time, due to the weak exciton coupling effect and the rigid flat structure, there is neither fluorescence quenching nor obvious emission enhancement phenomenon. The DPA single crystal possesses a slightly higher fluorescence quantum yield ~ 0.47 under pressure. Our work systematically explored the pressure-dependence photoelectric properties and explained the inside mechanism. Also, we proposed that the external pressure would be an effective way to improve the photoelectric performance of organic semiconductors.
2021, 32(3): 1237-1240
doi: 10.1016/j.cclet.2020.08.034
Abstract:
A nickel(Ⅱ)-catalyzed asymmetric alkylation of acyclic oxocarbenium ions generated in situ from corresponding acetals with carboxylic acid derivatives to prepare β-alkoxyl carbonyl moieties with diverse α-substituents has been disclosed. The method exhibited broad scope of acetals and carboxylic acid derivatives with excellent enantioselectivity and good functional group compatibility, and can be conducted in a gram-scale without obvious loss of efficiency.
A nickel(Ⅱ)-catalyzed asymmetric alkylation of acyclic oxocarbenium ions generated in situ from corresponding acetals with carboxylic acid derivatives to prepare β-alkoxyl carbonyl moieties with diverse α-substituents has been disclosed. The method exhibited broad scope of acetals and carboxylic acid derivatives with excellent enantioselectivity and good functional group compatibility, and can be conducted in a gram-scale without obvious loss of efficiency.
2021, 32(3): 1241-1244
doi: 10.1016/j.cclet.2020.09.011
Abstract:
A chiral cobalt pincer complex, when combined with an achiral electron-rich mono-phosphine ligand, catalyzes efficient asymmetric hydrogenation of a wide range of aryl ketones, affording chiral alcohols with high yields and moderate to excellent enantioselectivities (29 examples, up to 93% ee). Notably, the achiral mono-phosphine ligand shows a remarkable effect on the enantioselectivity of the reaction.
A chiral cobalt pincer complex, when combined with an achiral electron-rich mono-phosphine ligand, catalyzes efficient asymmetric hydrogenation of a wide range of aryl ketones, affording chiral alcohols with high yields and moderate to excellent enantioselectivities (29 examples, up to 93% ee). Notably, the achiral mono-phosphine ligand shows a remarkable effect on the enantioselectivity of the reaction.
2021, 32(3): 1245-1248
doi: 10.1016/j.cclet.2020.08.045
Abstract:
Charge transfer via electron hopping from an electron donor (D) to an acceptor (A) in nanoscale, plays a crucial role in optoelectronic materials, such as organic light-emitting diodes (OLEDs) and organic photovoltaic cells (OPVs). Here, we propose a strategy for binding D/A units in space, where intramolecular charge-transfer can take place. The resulted material DM-Me-B is able to give bright emission in this molecular architecture because of the good control of D/A interaction and conformational rigidity. Moreover, DM-Me-B presents small singlet-triplet splitting energy, enabling thermally activated delayed fluorescence. Therefore, the DM-Me-B exhibits ~20% maximum external quantum efficiency and low efficiency roll-off at 1000cd/m2, certifying an effective strategy in controlling D/A blocks through space.
Charge transfer via electron hopping from an electron donor (D) to an acceptor (A) in nanoscale, plays a crucial role in optoelectronic materials, such as organic light-emitting diodes (OLEDs) and organic photovoltaic cells (OPVs). Here, we propose a strategy for binding D/A units in space, where intramolecular charge-transfer can take place. The resulted material DM-Me-B is able to give bright emission in this molecular architecture because of the good control of D/A interaction and conformational rigidity. Moreover, DM-Me-B presents small singlet-triplet splitting energy, enabling thermally activated delayed fluorescence. Therefore, the DM-Me-B exhibits ~20% maximum external quantum efficiency and low efficiency roll-off at 1000cd/m2, certifying an effective strategy in controlling D/A blocks through space.
2021, 32(3): 1249-1252
doi: 10.1016/j.cclet.2020.08.047
Abstract:
The 1D microwires based on π-extended azaBODIPY were successfully prepared and characterized for the first time. The bisphenanthrene-fused azaBPP-12C with four hydrophobic chains was prepared through de novo synthesis method involving the Suzuki reaction and subsequent oxidative ring-fused coupling. The microwires and aggregation behavior were studied using SEM, XRD and absorption spectroscopy. Finally, an H-type aggregation was confirmed in the solution process.
The 1D microwires based on π-extended azaBODIPY were successfully prepared and characterized for the first time. The bisphenanthrene-fused azaBPP-12C with four hydrophobic chains was prepared through de novo synthesis method involving the Suzuki reaction and subsequent oxidative ring-fused coupling. The microwires and aggregation behavior were studied using SEM, XRD and absorption spectroscopy. Finally, an H-type aggregation was confirmed in the solution process.
2021, 32(3): 1253-1256
doi: 10.1016/j.cclet.2020.08.052
Abstract:
p-TsOH catalyzed Diels-Alder reaction of 3-(indol-3-yl)maleimides with 3-phenacylideneoxindoles in toluene at 80 ℃ for two hours afforded cis/trans isomers of 3a', 4′, 6′, 10c'-tetrahydrospiro[indoline-3, 5′-pyrrolo[3, 4-c]carbazoles] in nearly comparable yields, which could be easily converted to the corresponding 4′, 6′-dihydrospiro[indoline-3, 5′-pyrrolo[3, 4-c]carbazole] in high yields and with high diastereoselectivity by further DDQ oxidation., the similar reaction of 3-(indol-3-yl)maAdditionallyleimides with 2-arylidene-1, 3-indanediones in toluene 80 ℃ and sequential DDQ oxidation afforded functionalized dihydrospiro[indene-2, 5′-pyrrolo[3, 4-c]carbazoles] as major products.
p-TsOH catalyzed Diels-Alder reaction of 3-(indol-3-yl)maleimides with 3-phenacylideneoxindoles in toluene at 80 ℃ for two hours afforded cis/trans isomers of 3a', 4′, 6′, 10c'-tetrahydrospiro[indoline-3, 5′-pyrrolo[3, 4-c]carbazoles] in nearly comparable yields, which could be easily converted to the corresponding 4′, 6′-dihydrospiro[indoline-3, 5′-pyrrolo[3, 4-c]carbazole] in high yields and with high diastereoselectivity by further DDQ oxidation., the similar reaction of 3-(indol-3-yl)maAdditionallyleimides with 2-arylidene-1, 3-indanediones in toluene 80 ℃ and sequential DDQ oxidation afforded functionalized dihydrospiro[indene-2, 5′-pyrrolo[3, 4-c]carbazoles] as major products.
2021, 32(3): 1257-1262
doi: 10.1016/j.cclet.2020.08.051
Abstract:
Indacenodithiophene (IDT) derivatives are kinds of the most representative and widely used cores of small molecule acceptors (SMAs) in organic solar cells (OSCs). Here we systematically investigate the influence of end-group fluorination density and position on the photovoltaic properties of the IDT-based SMAs IDIC-nF (n=0, 2, 4). The absorption edge of IDIC-nF red-shifts with the π-π stacking and crystallinity improvement, and their electronic energy levels downshift with increasing n. Due to the advantages of Jsc and FF as well as acceptable Voc, the difluorinated IDIC-2F acceptor based OSCs achieve the highest power conversion efficiency (PCE) of 13%, better than the OSC devices based on IDIC and IDIC-4F as acceptors. And the photovoltaic performance of the PTQ10: IDIC-2F OSCs is insensitive to the active layer thickness: PCE still keep high values of 12.00% and 11.46% for the devices with active layer thickness of 80 and 354nm, respectively. This work verifies that fine and delicate modulation of the SMAs molecular structure could optimize photovoltaic performance of the corresponding OSCs. Meanwhile, the thickness-insensitivity property of the OSCs has potential for large-scale and printable fabrication technology.
Indacenodithiophene (IDT) derivatives are kinds of the most representative and widely used cores of small molecule acceptors (SMAs) in organic solar cells (OSCs). Here we systematically investigate the influence of end-group fluorination density and position on the photovoltaic properties of the IDT-based SMAs IDIC-nF (n=0, 2, 4). The absorption edge of IDIC-nF red-shifts with the π-π stacking and crystallinity improvement, and their electronic energy levels downshift with increasing n. Due to the advantages of Jsc and FF as well as acceptable Voc, the difluorinated IDIC-2F acceptor based OSCs achieve the highest power conversion efficiency (PCE) of 13%, better than the OSC devices based on IDIC and IDIC-4F as acceptors. And the photovoltaic performance of the PTQ10: IDIC-2F OSCs is insensitive to the active layer thickness: PCE still keep high values of 12.00% and 11.46% for the devices with active layer thickness of 80 and 354nm, respectively. This work verifies that fine and delicate modulation of the SMAs molecular structure could optimize photovoltaic performance of the corresponding OSCs. Meanwhile, the thickness-insensitivity property of the OSCs has potential for large-scale and printable fabrication technology.
2021, 32(3): 1263-1266
doi: 10.1016/j.cclet.2020.09.020
Abstract:
A highly novel and direct synthesis of benzoxazinones was developed via Cp*Co(Ⅲ)-catalyzed C–H activation and [3+3] annulation between sulfoxonium ylides and dioxazolones. The reaction is conducted under base-free conditions and tolerates various functional groups. Starting from diverse readily available sulfoxonium ylides and dioxazolones, a variety of benzoxazinones could be synthesized in one step in 32%-75% yields.
A highly novel and direct synthesis of benzoxazinones was developed via Cp*Co(Ⅲ)-catalyzed C–H activation and [3+3] annulation between sulfoxonium ylides and dioxazolones. The reaction is conducted under base-free conditions and tolerates various functional groups. Starting from diverse readily available sulfoxonium ylides and dioxazolones, a variety of benzoxazinones could be synthesized in one step in 32%-75% yields.
