2019 Volume 30 Issue 6
2019, 30(6): 1133-1136
doi: 10.1016/j.cclet.2019.02.022
Abstract:
Arsenic being one of the most toxic heavy metals has long been a focus of concern due to its gravest threats to human health and environment. Herein, we employ a new method named ring-opening click reaction to synthesize thiol-and amino-bifunctionalized SBA-15 (denoted as bi-SBA-15) for directly remove As(Ⅲ) without preoxidation As(Ⅲ) to As(Ⅴ) from contaminated water. Quite different from commonly modified with trialkoxysilanes, ring-opening click reaction is substantially faster (0.5-2 h at 25 ℃) and more efficient. The synthesized bi-SBA-15 exhibits excellent adsorption performance of As(Ⅲ) and As(Ⅴ) in an aqueous solution with a great adsorption capacity (33.70 mg/g and 42.66 mg/g, respectively), a very short equilibrium time (< 30 min), which is much faster than those of other adsorbents reported previously. The excellent adsorption performance of bi-SBA-15 can be maintained with a wide pH range (3-8), various anions and natural organic matter, which provides an effective approach and a new insight to clean arsenic-contaminated water.
Arsenic being one of the most toxic heavy metals has long been a focus of concern due to its gravest threats to human health and environment. Herein, we employ a new method named ring-opening click reaction to synthesize thiol-and amino-bifunctionalized SBA-15 (denoted as bi-SBA-15) for directly remove As(Ⅲ) without preoxidation As(Ⅲ) to As(Ⅴ) from contaminated water. Quite different from commonly modified with trialkoxysilanes, ring-opening click reaction is substantially faster (0.5-2 h at 25 ℃) and more efficient. The synthesized bi-SBA-15 exhibits excellent adsorption performance of As(Ⅲ) and As(Ⅴ) in an aqueous solution with a great adsorption capacity (33.70 mg/g and 42.66 mg/g, respectively), a very short equilibrium time (< 30 min), which is much faster than those of other adsorbents reported previously. The excellent adsorption performance of bi-SBA-15 can be maintained with a wide pH range (3-8), various anions and natural organic matter, which provides an effective approach and a new insight to clean arsenic-contaminated water.
2019, 30(6): 1137-1140
doi: 10.1016/j.cclet.2019.02.007
Abstract:
A novel supercapacitor based on ultralight and elastic three-dimensional (3D) porous melamine foam (MF)-derived macroporous carbon (3DPMFDMC)/reduced graphene oxide (rGO)/polyaniline (PANI) nanocomposites (denoted as 3DPMFDMC/rGO/PANI) were fabricated. By high temperature carbonization, the commercial MF soaked in GO solution was prepared into ultralight and elastic 3DPMFDMC, the rGO were uniformly distributed into 3DPMFDMC to obtain 3DPMFDMC/rGO, and finally PANI was grown on the 3DPMFDMC/rGO by using in situ chemical oxidation polymerization method. The obtained 3DPMFDMC/rGO/PANI nanocomposites were characterized by SEM, FT-IR and Raman. The results showed the uniform distribution of rGO connected the broken fibers of 3DPMFDMC produced in the high temperature carbonization to improve the electrical conductivity and also enlarged the specific surface area of nanocomposites greatly. Lots of PANI were vertically arrayed on the surface of 3DPMFDMC/rGO. 3DPMFDMC/rGO/PANI exhibited a rapid electron/mass transport. Owing to its special structures and nanocomposites, the supercapacitor showed good electrical performance with a specific capacitance of 1870 F/g at the current density of 1 A/g. Moreover, the specific capacitance remained 95.4% after 1000 charging/discharging cycles at a current density of 5 A/g.
A novel supercapacitor based on ultralight and elastic three-dimensional (3D) porous melamine foam (MF)-derived macroporous carbon (3DPMFDMC)/reduced graphene oxide (rGO)/polyaniline (PANI) nanocomposites (denoted as 3DPMFDMC/rGO/PANI) were fabricated. By high temperature carbonization, the commercial MF soaked in GO solution was prepared into ultralight and elastic 3DPMFDMC, the rGO were uniformly distributed into 3DPMFDMC to obtain 3DPMFDMC/rGO, and finally PANI was grown on the 3DPMFDMC/rGO by using in situ chemical oxidation polymerization method. The obtained 3DPMFDMC/rGO/PANI nanocomposites were characterized by SEM, FT-IR and Raman. The results showed the uniform distribution of rGO connected the broken fibers of 3DPMFDMC produced in the high temperature carbonization to improve the electrical conductivity and also enlarged the specific surface area of nanocomposites greatly. Lots of PANI were vertically arrayed on the surface of 3DPMFDMC/rGO. 3DPMFDMC/rGO/PANI exhibited a rapid electron/mass transport. Owing to its special structures and nanocomposites, the supercapacitor showed good electrical performance with a specific capacitance of 1870 F/g at the current density of 1 A/g. Moreover, the specific capacitance remained 95.4% after 1000 charging/discharging cycles at a current density of 5 A/g.
2019, 30(6): 1141-1146
doi: 10.1016/j.cclet.2019.03.031
Abstract:
With the objective to develop catalysts having application potential for oxidative coupling of methane (OCM) at relatively lower temperature. A series of Ln2Zr2O7 compounds with varied rare earth A sites have been prepared by a co-precipitation method. XRD and Raman have proved that pure Ln2Zr2O7 compounds have been successfully prepared for all the catalysts. By decreasing the rA/rB ratio, their crystalline structure transform from an ordered pyrochlore (La2Zr2O7) to a less ordered pyrochlore (Pr2Zr2O7 and Sm2Zr2O7) and eventually to a defective cubic fluorite phase (Y2Zr2O7). H2-TPR, O2-TPD and XPS have testified that the amount of surface active O2- species follows the order of La2Zr2O7 > Pr2Zr2O7 > Sm2Zr2O7 > Y2Zr2O7, which is well consistent with the reaction performance, indicating that the abundance of surface O2- sites is a critical factor influencing the reaction performance. CO2-TPD has demonstrated that a better catalyst generally possesses a larger amount of surface moderate alkaline sites, which is another factor to affect the reaction performance. It is concluded that the concerted interaction between the two types of surface active sites controls the reaction performance of the Ln2Zr2O7 catalysts. In comparison with the state-of-the art Mn/Na2WO4/SiO2, La2Zr2O7, the best catalyst, exhibits much improved reaction performance below 750℃.
With the objective to develop catalysts having application potential for oxidative coupling of methane (OCM) at relatively lower temperature. A series of Ln2Zr2O7 compounds with varied rare earth A sites have been prepared by a co-precipitation method. XRD and Raman have proved that pure Ln2Zr2O7 compounds have been successfully prepared for all the catalysts. By decreasing the rA/rB ratio, their crystalline structure transform from an ordered pyrochlore (La2Zr2O7) to a less ordered pyrochlore (Pr2Zr2O7 and Sm2Zr2O7) and eventually to a defective cubic fluorite phase (Y2Zr2O7). H2-TPR, O2-TPD and XPS have testified that the amount of surface active O2- species follows the order of La2Zr2O7 > Pr2Zr2O7 > Sm2Zr2O7 > Y2Zr2O7, which is well consistent with the reaction performance, indicating that the abundance of surface O2- sites is a critical factor influencing the reaction performance. CO2-TPD has demonstrated that a better catalyst generally possesses a larger amount of surface moderate alkaline sites, which is another factor to affect the reaction performance. It is concluded that the concerted interaction between the two types of surface active sites controls the reaction performance of the Ln2Zr2O7 catalysts. In comparison with the state-of-the art Mn/Na2WO4/SiO2, La2Zr2O7, the best catalyst, exhibits much improved reaction performance below 750℃.
2019, 30(6): 1147-1152
doi: 10.1016/j.cclet.2019.03.047
Abstract:
The density functional theory was employed to investigate the adsorption of Nin (n=1-4) on the perfect and O-defect CuAl2O4 surfaces. The computational results show that for single Ni atom on the perfect spinel (100) surface, the adsorption energy is -5.30 eV, much larger than Ni on other CuAl2O4 surfaces. The adsorption of Nin (n=1-4) absorbed on the O-defect CuAl2O4 (100) surface is less stable than on the perfect CuAl2O4 (100) surface. However, the adsorption energy for Nin (n=1-4) on the O-defect CuAl2O4 (110) surface is close to on the perfect CuAl2O4 (110) surface. Bader charge and partial density of states (PDOS) analysis revel that the adsorption of Ni on the CuAl2O4 spinel surface is accompanied by charge transfer from the metal to the support. The growth and aggregations analysis show that the general growth and aggregation ability for Nin clusters follow the order:gas phase > γ-Al2O3 (110) > CuAl2O4 (110) > CuAl2O4 (100). This result can give reasonable explanations for the experimental phenomenon that Ni supported on the CuAl2O4 spinel performs much better stability than on the γ-Al2O3.
The density functional theory was employed to investigate the adsorption of Nin (n=1-4) on the perfect and O-defect CuAl2O4 surfaces. The computational results show that for single Ni atom on the perfect spinel (100) surface, the adsorption energy is -5.30 eV, much larger than Ni on other CuAl2O4 surfaces. The adsorption of Nin (n=1-4) absorbed on the O-defect CuAl2O4 (100) surface is less stable than on the perfect CuAl2O4 (100) surface. However, the adsorption energy for Nin (n=1-4) on the O-defect CuAl2O4 (110) surface is close to on the perfect CuAl2O4 (110) surface. Bader charge and partial density of states (PDOS) analysis revel that the adsorption of Ni on the CuAl2O4 spinel surface is accompanied by charge transfer from the metal to the support. The growth and aggregations analysis show that the general growth and aggregation ability for Nin clusters follow the order:gas phase > γ-Al2O3 (110) > CuAl2O4 (110) > CuAl2O4 (100). This result can give reasonable explanations for the experimental phenomenon that Ni supported on the CuAl2O4 spinel performs much better stability than on the γ-Al2O3.
2019, 30(6): 1153-1156
doi: 10.1016/j.cclet.2019.03.030
Abstract:
The content of noble metal loading and the reduction process of the catalysts are important factors influence the economic indicator and catalytic performance for industrial catalysis. In the present work, Pd/CeO2NT (Pd supported on the CeO2 nanotubes) catalysts are prepared with the hydrothermal synthesized CeO2NTand glutathione (GSH) reduced Pd nanoparticles via impregnation. The content of Pd loading as well as the catalysts reduction temperature are optimized to the CO oxidation reduction. Our results show that the best Pd loading is 1.5%Pd/CeO2NT. The catalysts reduced at 350℃ for 2 h prior to catalytic reaction perform the best toward CO oxidation, which reaches completely CO conversion at 70℃. The XRD, Raman, H2-TPR, TEM, BET and XPS characterization reveal that the excellent catalytic performance of 350℃ 1.5%Pd/CeO2NT sample can be attributed the high Pd0 species and oxygen vacancy in the sample, which are important factors influence the activity of the catalysts.
The content of noble metal loading and the reduction process of the catalysts are important factors influence the economic indicator and catalytic performance for industrial catalysis. In the present work, Pd/CeO2NT (Pd supported on the CeO2 nanotubes) catalysts are prepared with the hydrothermal synthesized CeO2NTand glutathione (GSH) reduced Pd nanoparticles via impregnation. The content of Pd loading as well as the catalysts reduction temperature are optimized to the CO oxidation reduction. Our results show that the best Pd loading is 1.5%Pd/CeO2NT. The catalysts reduced at 350℃ for 2 h prior to catalytic reaction perform the best toward CO oxidation, which reaches completely CO conversion at 70℃. The XRD, Raman, H2-TPR, TEM, BET and XPS characterization reveal that the excellent catalytic performance of 350℃ 1.5%Pd/CeO2NT sample can be attributed the high Pd0 species and oxygen vacancy in the sample, which are important factors influence the activity of the catalysts.
2019, 30(6): 1157-1160
doi: 10.1016/j.cclet.2019.04.009
Abstract:
Nanocomposite of Co3O4 and multiwalled carbon nanotube (MCNT) was synthesised using one step solvothermal method, and an electrochemical non-enzymatic glucose sensor (Co3O4-MCNT/GCE) was successfully constructed by a dropping method. The obtained Co3O4 and Co3O4- MCNT were characterized and investigated by transmission electron microscopy (TEM) and energy dispersive Xray spectroscopy (EDS). Quantitative analysis of glucose was performed using the amperometric (i-t) method, and plot of current difference versus concentration of glucose was linear in the range of 1.0-122 μmol/L, with a linear correlation coefficient (R2) of 0.9983 and limit of detection (LOD) of 0.28 μmol/L. Sensitivity of this sensor was evaluated as 2550 μA L mmol-1 cm-2. This new sensor produced satisfactory reproducibility and stability and was applied to monitor trace amounts of glucose in human serum samples.
Nanocomposite of Co3O4 and multiwalled carbon nanotube (MCNT) was synthesised using one step solvothermal method, and an electrochemical non-enzymatic glucose sensor (Co3O4-MCNT/GCE) was successfully constructed by a dropping method. The obtained Co3O4 and Co3O4- MCNT were characterized and investigated by transmission electron microscopy (TEM) and energy dispersive Xray spectroscopy (EDS). Quantitative analysis of glucose was performed using the amperometric (i-t) method, and plot of current difference versus concentration of glucose was linear in the range of 1.0-122 μmol/L, with a linear correlation coefficient (R2) of 0.9983 and limit of detection (LOD) of 0.28 μmol/L. Sensitivity of this sensor was evaluated as 2550 μA L mmol-1 cm-2. This new sensor produced satisfactory reproducibility and stability and was applied to monitor trace amounts of glucose in human serum samples.
2019, 30(6): 1161-1167
doi: 10.1016/j.cclet.2019.04.029
Abstract:
In this study, a series of random conjugated polymers (PBDB-TBTn) as donors were designed and synthesized. In these polymers, benzodithiophene unit with thiophene conjugated side chains (BDT) are donor part, and two different content of benzo[1, 2-c:4, 5-c']dithiophene-4, 8-dione (BDD) and difluorobenzothiadizole (BT) linked alkylthiophene are acceptor unit. Polymer solar cells (PSCs) were fabricated with ITIC as an acceptor, and over the power conversion efficiency (PCE) of 9% was obtained, with open circuit voltage (Voc) of 0.86 V, short-circuit current density (Jsc) of 16.84 mA/cm2, and fill factor (FF) of 62.5%. These random conjugated polymers based solar cells are insensitive to solvent additives and thermal annealing. The performance of the device decreases gradually with the increasing of the proportion of fluorinated acceptor unit. The declining efficiency is due to the excessive fluorinated acceptor unit, which leads to over aggregated topography, destroys the effective charge transport pathways, and affects phase separation domain size between the donor and the acceptor. The phenomena are explained by the charge carrier recombination, atomic force microscope (AFM), and transmission electron microscope (TEM). These results indicate that proper addition of fluorinated acceptor units to build random copolymers can enhance the efficiency of organic photovoltaics toward additive-free and thermal annealing-free PSCs.
In this study, a series of random conjugated polymers (PBDB-TBTn) as donors were designed and synthesized. In these polymers, benzodithiophene unit with thiophene conjugated side chains (BDT) are donor part, and two different content of benzo[1, 2-c:4, 5-c']dithiophene-4, 8-dione (BDD) and difluorobenzothiadizole (BT) linked alkylthiophene are acceptor unit. Polymer solar cells (PSCs) were fabricated with ITIC as an acceptor, and over the power conversion efficiency (PCE) of 9% was obtained, with open circuit voltage (Voc) of 0.86 V, short-circuit current density (Jsc) of 16.84 mA/cm2, and fill factor (FF) of 62.5%. These random conjugated polymers based solar cells are insensitive to solvent additives and thermal annealing. The performance of the device decreases gradually with the increasing of the proportion of fluorinated acceptor unit. The declining efficiency is due to the excessive fluorinated acceptor unit, which leads to over aggregated topography, destroys the effective charge transport pathways, and affects phase separation domain size between the donor and the acceptor. The phenomena are explained by the charge carrier recombination, atomic force microscope (AFM), and transmission electron microscope (TEM). These results indicate that proper addition of fluorinated acceptor units to build random copolymers can enhance the efficiency of organic photovoltaics toward additive-free and thermal annealing-free PSCs.
2019, 30(6): 1168-1172
doi: 10.1016/j.cclet.2019.04.054
Abstract:
The underpotential adsorption of hydrogen (HUPD) is one of the most attractive fields in surface electrochemistry and electrocatalysis. In this work, the hydrogen adsorption on polycrystalline platinum electrode experimentally as well as on single crystal Pt(110) and Pt(100) electrode theoretically were studied. The effect of forced convection on the adsorption and desorption process of hydrogen was studied through adjusting the sampling rate of the microporous sampler closing to the surface of the platinum electrode immersed in dilute sulfuric acid solution. The relationship between HUPD and surface structure sensitivity was built quantitively. The DFT simulation shows that the adsorption strength of hydrogen on Pt(100), due to the lower adsorption energy, is weaker than that on Pt(110). Moreover, the bridged position of hydrogen on Pt(100) and the short-range bridged position on Pt(110) were found to be the optimal adsorption sites. The study of forced convection on the electrode surface promotes the HUPD research from static process to a convective mode and also provides a new strategy to investigate the hydrogen adsorption in solution.
The underpotential adsorption of hydrogen (HUPD) is one of the most attractive fields in surface electrochemistry and electrocatalysis. In this work, the hydrogen adsorption on polycrystalline platinum electrode experimentally as well as on single crystal Pt(110) and Pt(100) electrode theoretically were studied. The effect of forced convection on the adsorption and desorption process of hydrogen was studied through adjusting the sampling rate of the microporous sampler closing to the surface of the platinum electrode immersed in dilute sulfuric acid solution. The relationship between HUPD and surface structure sensitivity was built quantitively. The DFT simulation shows that the adsorption strength of hydrogen on Pt(100), due to the lower adsorption energy, is weaker than that on Pt(110). Moreover, the bridged position of hydrogen on Pt(100) and the short-range bridged position on Pt(110) were found to be the optimal adsorption sites. The study of forced convection on the electrode surface promotes the HUPD research from static process to a convective mode and also provides a new strategy to investigate the hydrogen adsorption in solution.
2019, 30(6): 1173-1177
doi: 10.1016/j.cclet.2019.04.053
Abstract:
A metal-free cross coupling between common CH2Cl2 and carboxylic acids has been achieved with K2CO3 as the sole additive. This simple protocol is a convenient and cost-effective route to synthesize methylene diesters from a wide scope of carboxylic acids substrates with good functional group tolerance. Several gram-scale reactions have been performed to evaluate the effectiveness and practicality of this protocol.
A metal-free cross coupling between common CH2Cl2 and carboxylic acids has been achieved with K2CO3 as the sole additive. This simple protocol is a convenient and cost-effective route to synthesize methylene diesters from a wide scope of carboxylic acids substrates with good functional group tolerance. Several gram-scale reactions have been performed to evaluate the effectiveness and practicality of this protocol.
2019, 30(6): 1178-1181
doi: 10.1016/j.cclet.2019.04.061
Abstract:
Black fungus derived carbonaceous aerogel (BFA) was prepared via a convenient and energy efficient ultrasonic disposal process. The adsorption experiments of atmospheric pollutants demonstrated the superior adsorbability of black fungus aerogel on PM2.5, PM10 and formaldehyde. More importantly, black fungus aerogel (BFA) exhibited intriguing double-faced properties. We explored properties of each side of the black fungus from three aspects:water contact angle measurements, liquid selective absorption capacity and air pollutant adsorption abilities. The subsequent modification of ZnO nanosheets endowed the prepared black fungus aerogel with several valuable properties, including broad-spectrum antibacterial capability and high-efficient adsorption ability. These valuable characters implied the BFA to be a promising bacteriostat and cleaner for air and water pollution treatment.
Black fungus derived carbonaceous aerogel (BFA) was prepared via a convenient and energy efficient ultrasonic disposal process. The adsorption experiments of atmospheric pollutants demonstrated the superior adsorbability of black fungus aerogel on PM2.5, PM10 and formaldehyde. More importantly, black fungus aerogel (BFA) exhibited intriguing double-faced properties. We explored properties of each side of the black fungus from three aspects:water contact angle measurements, liquid selective absorption capacity and air pollutant adsorption abilities. The subsequent modification of ZnO nanosheets endowed the prepared black fungus aerogel with several valuable properties, including broad-spectrum antibacterial capability and high-efficient adsorption ability. These valuable characters implied the BFA to be a promising bacteriostat and cleaner for air and water pollution treatment.
DES-Fe3O4 composite for rapid extraction of residual plant growth regulators in edible vegetable oil
2019, 30(6): 1182-1185
doi: 10.1016/j.cclet.2019.03.057
Abstract:
A rapid DES-Fe3O4 microextraction coupled with liquid chromatography method was ingeniously developed for simultaneous control of five typical plant growth regulators in a planting cycle including indole-3-acetic acid, abscisic acid, thidiazuron, 1-naphthylacetic acid and forchlorfenuron. The experiments were carried out with one type of carboxylic acid-assisted deep eutectic solvent (nChCl:nacetic acid=1:3) as extractant, coupled with ultrasonic wave extraction for 30 min at bath temperature at 50 C. Under the optimum conditions, good extraction performances of linearities for five plant growth regulators were achieved separately in the range of 0.10-50 mg/L of indole-3-acetic acid, 0.06-50 mg/L of abscisic acid, 0.20-50 mg/L of thidiazuron, 0.50-50 mg/L of 1-naphthylacetic acid and 0.06-50 mg/L of forchlorfenuron and recoveries were ranged from 70.4% to 102.2%. Meanwhile, Fe3O4 was preferentially combined with DES in the oil matrix, the advantage of which was pointed to rapid and efficient separation of targeted plant growth regulators from complicated oil matrix. The proposed approach achieved satisfied results and met the monitoring requirements of plant growth regulators control in edible vegetable oil samples.
A rapid DES-Fe3O4 microextraction coupled with liquid chromatography method was ingeniously developed for simultaneous control of five typical plant growth regulators in a planting cycle including indole-3-acetic acid, abscisic acid, thidiazuron, 1-naphthylacetic acid and forchlorfenuron. The experiments were carried out with one type of carboxylic acid-assisted deep eutectic solvent (nChCl:nacetic acid=1:3) as extractant, coupled with ultrasonic wave extraction for 30 min at bath temperature at 50 C. Under the optimum conditions, good extraction performances of linearities for five plant growth regulators were achieved separately in the range of 0.10-50 mg/L of indole-3-acetic acid, 0.06-50 mg/L of abscisic acid, 0.20-50 mg/L of thidiazuron, 0.50-50 mg/L of 1-naphthylacetic acid and 0.06-50 mg/L of forchlorfenuron and recoveries were ranged from 70.4% to 102.2%. Meanwhile, Fe3O4 was preferentially combined with DES in the oil matrix, the advantage of which was pointed to rapid and efficient separation of targeted plant growth regulators from complicated oil matrix. The proposed approach achieved satisfied results and met the monitoring requirements of plant growth regulators control in edible vegetable oil samples.
2019, 30(6): 1198-1203
doi: 10.1016/j.cclet.2019.01.021
Abstract:
A series of spinel ferrites magnetic nanoparticles NiFe2O4 were synthesized as the heterogeneous Fentonlike catalyst by hydrothermal method and then NiFe2O4@SiO2 catalysts were obtained by the modification of NiFe2O4 via micro emulsion method. XRD, VSM, FTIR, SEM, TEM, BET and XPS were carried to analyze the difference between the above two catalysts. NiFe2O4@SiO2 catalyst exhibited the higher catalytic activity than NiFe2O4 for the degradation of Rhodamine B owe to the outer SiO2 layers surface, the more important is both of them showed the better catalytic performance when at neutral pH environment.
A series of spinel ferrites magnetic nanoparticles NiFe2O4 were synthesized as the heterogeneous Fentonlike catalyst by hydrothermal method and then NiFe2O4@SiO2 catalysts were obtained by the modification of NiFe2O4 via micro emulsion method. XRD, VSM, FTIR, SEM, TEM, BET and XPS were carried to analyze the difference between the above two catalysts. NiFe2O4@SiO2 catalyst exhibited the higher catalytic activity than NiFe2O4 for the degradation of Rhodamine B owe to the outer SiO2 layers surface, the more important is both of them showed the better catalytic performance when at neutral pH environment.
2019, 30(6): 1204-1206
doi: 10.1016/j.cclet.2019.01.016
Abstract:
LTA (Linde Type A) molecular sieve has widely used in adsorption and separation due to its regular pore structure, high thermal stability and chemical stability. Copper-exchanged LTA (Cu-LTA) zeolite membranes with enhanced water flux of ethanol dehydration were developed through copper ion exchange of Na-LTA zeolite membrane. In the first step, a thin and well intergrown Na-LTA zeolite membrane was prepared on macroporous α-Al2O3 tube which was modified by 3-aminopropyltriethoxysilane (APTES). Afterwards, copper exchange of the as-synthesized Na-LTA zeolite membranes was done to prepare Cu-LTA zeolite membrane. According to characterizations of XRD, FESEM, and XPS, both the morphology and structure of the Cu-LTA zeolite membranes are identical to those of the Na-LTA zeolite membranes, and there are no cracks and pinholes are found in the membrane layer. Attributing to a wider pore diameter because two sodium ions of Na-LTA framework are replaced by one copper ion, the Cu-LTA zeolite membrane displays a higher water flux in the separation of ethanol/water mixture than Na-LTA membranes. At 75℃, the water flux of the Cu-LTA zeolite membrane is 3.52 kg m-2 h-1 with water/ethanol separation factor of 3591, while the water flux of the Na-LTA zeolite membrane is only 1.65 kg m-2 h-1 with water/ethanol separation factor of 4082.
LTA (Linde Type A) molecular sieve has widely used in adsorption and separation due to its regular pore structure, high thermal stability and chemical stability. Copper-exchanged LTA (Cu-LTA) zeolite membranes with enhanced water flux of ethanol dehydration were developed through copper ion exchange of Na-LTA zeolite membrane. In the first step, a thin and well intergrown Na-LTA zeolite membrane was prepared on macroporous α-Al2O3 tube which was modified by 3-aminopropyltriethoxysilane (APTES). Afterwards, copper exchange of the as-synthesized Na-LTA zeolite membranes was done to prepare Cu-LTA zeolite membrane. According to characterizations of XRD, FESEM, and XPS, both the morphology and structure of the Cu-LTA zeolite membranes are identical to those of the Na-LTA zeolite membranes, and there are no cracks and pinholes are found in the membrane layer. Attributing to a wider pore diameter because two sodium ions of Na-LTA framework are replaced by one copper ion, the Cu-LTA zeolite membrane displays a higher water flux in the separation of ethanol/water mixture than Na-LTA membranes. At 75℃, the water flux of the Cu-LTA zeolite membrane is 3.52 kg m-2 h-1 with water/ethanol separation factor of 3591, while the water flux of the Na-LTA zeolite membrane is only 1.65 kg m-2 h-1 with water/ethanol separation factor of 4082.
2019, 30(6): 1207-1213
doi: 10.1016/j.cclet.2019.02.033
Abstract:
To explore new skeleton with nematicidal activity, a series of novel 1,2,3-benzotriazin-4-one derivatives containing piperazine as linker were synthesized and varied fragments were also introduced to increase structure diversity of the new skeleton. Their inhibitory activities in vivo were evaluated against Meloidogyne incognita. The newly prepared compounds A6, A8, A21, A28 and A38 exhibited more than 50% inhibition at the concentration of 20 mg/L. Especially compound A6 displayed 71.4% inhibition against Meloidogyne incognita at the concentration of 20 mg/L. The nematicidal activities varied significantly depending on the types and positions of the substituents, which provided guidance for further structure modification.
To explore new skeleton with nematicidal activity, a series of novel 1,2,3-benzotriazin-4-one derivatives containing piperazine as linker were synthesized and varied fragments were also introduced to increase structure diversity of the new skeleton. Their inhibitory activities in vivo were evaluated against Meloidogyne incognita. The newly prepared compounds A6, A8, A21, A28 and A38 exhibited more than 50% inhibition at the concentration of 20 mg/L. Especially compound A6 displayed 71.4% inhibition against Meloidogyne incognita at the concentration of 20 mg/L. The nematicidal activities varied significantly depending on the types and positions of the substituents, which provided guidance for further structure modification.
2019, 30(6): 1214-1218
doi: 10.1016/j.cclet.2019.03.002
Abstract:
A novel carbon quantum dots modified potassium titanate nanotubes (CQDs/K2Ti6O13) composite photocatalyst was synthesized by hydrothermal treatment combined with calcination. X-ray diffraction (XRD) pattern and transmission electron microscopy (TEM) indicated formation of potassium titanate nanotubes and successful deposition of CQDs onto K2Ti6O13. The photocatalytic performance of CQDs/K2Ti6O13 composite was evaluated by degradation of amoxicillin (AMX) under the irradiation of visible light and lights with the wavelengths of 365, 385, 420, 450, 485, 520, 595 and 630 nm. The results showed that the photocatalytic activity of CQDs/K2Ti6O13 hybrid material was greatly enhanced compared with the neat K2Ti6O13 calcined at 300 ℃. The narrowed band gap energy (Eg) and transfer of photo-excited electron by CQDs inhibited the immediate combination of electron-hole pairs, thus promoting photocatalytic activity. Moreover, CQDs/K2Ti6O13 exhibited a broad spectrum of photocatalytic ability and it was interesting that the photocatalytic activity decreased with the increase of the irradiation wavelength. Reactive oxygen species (ROS) quenching tests suggested the hole (h+) and hydroxyl radical (·OH) played the primary roles in photocatalytic degradation of AMX. Moreover, CQDs/K2Ti6O13 showed good reusability for AMX photocatalytic degradation after five successive runs. This study proposed an available method for titanate nanomaterials modification, and the developed novel CQDs/K2Ti6O13 hybrid material is promising for potential application on antibiotics removal from water and wastewater.
A novel carbon quantum dots modified potassium titanate nanotubes (CQDs/K2Ti6O13) composite photocatalyst was synthesized by hydrothermal treatment combined with calcination. X-ray diffraction (XRD) pattern and transmission electron microscopy (TEM) indicated formation of potassium titanate nanotubes and successful deposition of CQDs onto K2Ti6O13. The photocatalytic performance of CQDs/K2Ti6O13 composite was evaluated by degradation of amoxicillin (AMX) under the irradiation of visible light and lights with the wavelengths of 365, 385, 420, 450, 485, 520, 595 and 630 nm. The results showed that the photocatalytic activity of CQDs/K2Ti6O13 hybrid material was greatly enhanced compared with the neat K2Ti6O13 calcined at 300 ℃. The narrowed band gap energy (Eg) and transfer of photo-excited electron by CQDs inhibited the immediate combination of electron-hole pairs, thus promoting photocatalytic activity. Moreover, CQDs/K2Ti6O13 exhibited a broad spectrum of photocatalytic ability and it was interesting that the photocatalytic activity decreased with the increase of the irradiation wavelength. Reactive oxygen species (ROS) quenching tests suggested the hole (h+) and hydroxyl radical (·OH) played the primary roles in photocatalytic degradation of AMX. Moreover, CQDs/K2Ti6O13 showed good reusability for AMX photocatalytic degradation after five successive runs. This study proposed an available method for titanate nanomaterials modification, and the developed novel CQDs/K2Ti6O13 hybrid material is promising for potential application on antibiotics removal from water and wastewater.
2019, 30(6): 1219-1223
doi: 10.1016/j.cclet.2019.03.018
Abstract:
Although the degradation mechanism of straw anaerobic digestion is still obscure, lower temperature thermophysical pretreatment might be a feasible way to improve biogas fermentation efficiency and net energy production in whole slurry. In this study, the performances of rice straw (RS) degradation and biogas production were examined at different pretreatment temperatures from 90℃ to 130℃ to identify the optimal process. With increasing pretreatment temperature, the change in cellulose and hemicellulose degradation in all the tests was directly related to volatile fatty acids (VFAs) content, but did not correspond to the variation in cumulative methane production. Both 100℃ and 130℃ presented similar ideal digestion performances with highest methane yields of 127.6 and 124.6 mL/g TS, respectively, which were 22.80% and 19.83% higher than that noted in the control. Although test at 100℃ pretreatment, which achieved 12.8% higher net energy production from RS than that observed in the control, could be considered as the optimal choice, the surplus biogas could only meet 75.9% of energy requirement for pretreated water temperature shift. Nevertheless, mesophilic or thermophilic fermentation, lower pretreatment water input, and reuse of excess heat are recommended as feasible working conditions for improving net biogas production.
Although the degradation mechanism of straw anaerobic digestion is still obscure, lower temperature thermophysical pretreatment might be a feasible way to improve biogas fermentation efficiency and net energy production in whole slurry. In this study, the performances of rice straw (RS) degradation and biogas production were examined at different pretreatment temperatures from 90℃ to 130℃ to identify the optimal process. With increasing pretreatment temperature, the change in cellulose and hemicellulose degradation in all the tests was directly related to volatile fatty acids (VFAs) content, but did not correspond to the variation in cumulative methane production. Both 100℃ and 130℃ presented similar ideal digestion performances with highest methane yields of 127.6 and 124.6 mL/g TS, respectively, which were 22.80% and 19.83% higher than that noted in the control. Although test at 100℃ pretreatment, which achieved 12.8% higher net energy production from RS than that observed in the control, could be considered as the optimal choice, the surplus biogas could only meet 75.9% of energy requirement for pretreated water temperature shift. Nevertheless, mesophilic or thermophilic fermentation, lower pretreatment water input, and reuse of excess heat are recommended as feasible working conditions for improving net biogas production.
2019, 30(6): 1224-1228
doi: 10.1016/j.cclet.2019.03.042
Abstract:
Recently we found that multi-walled carbon nanotube (MWCNT) exposure alters the mRNA levels of endoplasmic reticulum (ER) stress/autophagic genes, but the impact of biological molecules on this response is unclear. Herein, we compared the different actions of carboxylated MWCNTs (c-MWCNTs) pre-incubated with bovine serum albumin (BSA) or BSA-complexed free fatty acid (denoted as FFA) on macrophages derived from THP-1 monocytes (denoted as THP-1 macrophages). C-MWCNTs exhibited increased diameter and hydrodynamic size as well as decreased absolute zeta potential value after preincubation with BSA or FFA, which suggested a coating effect. Cytotoxicity or oxidative stress were not significantly induced after exposure to BSA-or FFA-coated c-MWCNTs. BSA-pre-incubated c-MWCNTs significantly enhanced the expression of the ER stress gene, DDIT3 and the autophagic genes, ATG5, BECN1, and PLIN2, but the mRNA levels of these genes was significantly decreased by FFA-pre-incubated c-MWCNTs. FFA-pre-incubated c-MWCNTs induced significantly higher lipid accumulation and interleukin-6 (IL-6) protein level compared with BSA-pre-incubated c-MWCNTs, which suggested that FFA-pre-incubated c-MWCNTs may more effectively induce the formation of macrophage foam cells. Collectively, our data indicated that pre-incubation with FFA may influence c-MWCNT-induced ER stress/autophagic gene expression and foam cell formation in THP-1 macrophages.
Recently we found that multi-walled carbon nanotube (MWCNT) exposure alters the mRNA levels of endoplasmic reticulum (ER) stress/autophagic genes, but the impact of biological molecules on this response is unclear. Herein, we compared the different actions of carboxylated MWCNTs (c-MWCNTs) pre-incubated with bovine serum albumin (BSA) or BSA-complexed free fatty acid (denoted as FFA) on macrophages derived from THP-1 monocytes (denoted as THP-1 macrophages). C-MWCNTs exhibited increased diameter and hydrodynamic size as well as decreased absolute zeta potential value after preincubation with BSA or FFA, which suggested a coating effect. Cytotoxicity or oxidative stress were not significantly induced after exposure to BSA-or FFA-coated c-MWCNTs. BSA-pre-incubated c-MWCNTs significantly enhanced the expression of the ER stress gene, DDIT3 and the autophagic genes, ATG5, BECN1, and PLIN2, but the mRNA levels of these genes was significantly decreased by FFA-pre-incubated c-MWCNTs. FFA-pre-incubated c-MWCNTs induced significantly higher lipid accumulation and interleukin-6 (IL-6) protein level compared with BSA-pre-incubated c-MWCNTs, which suggested that FFA-pre-incubated c-MWCNTs may more effectively induce the formation of macrophage foam cells. Collectively, our data indicated that pre-incubation with FFA may influence c-MWCNT-induced ER stress/autophagic gene expression and foam cell formation in THP-1 macrophages.
2019, 30(6): 1229-1232
doi: 10.1016/j.cclet.2019.03.028
Abstract:
Virus spread is closely related to pathogenesis. Traditional research methods of virus spread do not distinguish cell-to-cell spread from cell-free spread. The uncertainty of virus induced plaque and virus spread direction makes it difficult to track the spread of virus in situ. Herein, the cellular network was fabricated on the basis of PEG modification and soft lithography. Therein, cell numbers and spatial distributions were precisely controlled, e.g., cellular networks like "WHU" can be achieved. Furthermore, a micro-injector was combined with the cellular network for virus spread on the fixed point, in which virus spread direction was limited in one dimension. The results suggested that controllable and flexible cellular network can be constructed on the PEG pattern. The synergia of micro-injector and cellular network provides an advanced tool to investigate virus cell-to-cell spread at the initial infection stage.
Virus spread is closely related to pathogenesis. Traditional research methods of virus spread do not distinguish cell-to-cell spread from cell-free spread. The uncertainty of virus induced plaque and virus spread direction makes it difficult to track the spread of virus in situ. Herein, the cellular network was fabricated on the basis of PEG modification and soft lithography. Therein, cell numbers and spatial distributions were precisely controlled, e.g., cellular networks like "WHU" can be achieved. Furthermore, a micro-injector was combined with the cellular network for virus spread on the fixed point, in which virus spread direction was limited in one dimension. The results suggested that controllable and flexible cellular network can be constructed on the PEG pattern. The synergia of micro-injector and cellular network provides an advanced tool to investigate virus cell-to-cell spread at the initial infection stage.
2019, 30(6): 1233-1236
doi: 10.1016/j.cclet.2019.03.029
Abstract:
Multiple histone deacetylase inhibitors (HDACi) and DNA methyltransferase inhibitors (DNMTi) have been developed for cancer therapy. However, the research on their mechanisms of action is not sophisticated enough. In this study, we reported a dual HDAC and DNMT inhibitor 208 and found it induced G1 cell cycle arrest and apoptosis in U937 cells. Proteome and bioinformatic analyses revealed that the combined inhibition of DNMT1 and HDAC by 208 affected the expression of a series of proteins involved in many biological processes. We observed that several proteins associated with G1 cell cycle arrest and apoptosis were down regulated after 208 treatment, including p85α, MEK, and CDK4, suggesting that 208 induces cell cycle arrest and apoptosis through the p85α/MEK-mediated pathway in U937 cells. Moreover, biological function analysis showed that the combined epigenetic inhibition influenced various processes, including the synthesis and processing of RNA, translation, protein transport, and DNA repair. These findings provide novel insight into the potential mechanisms of multifunctional epigenetic inhibitors, which supports their further improvement and development.
Multiple histone deacetylase inhibitors (HDACi) and DNA methyltransferase inhibitors (DNMTi) have been developed for cancer therapy. However, the research on their mechanisms of action is not sophisticated enough. In this study, we reported a dual HDAC and DNMT inhibitor 208 and found it induced G1 cell cycle arrest and apoptosis in U937 cells. Proteome and bioinformatic analyses revealed that the combined inhibition of DNMT1 and HDAC by 208 affected the expression of a series of proteins involved in many biological processes. We observed that several proteins associated with G1 cell cycle arrest and apoptosis were down regulated after 208 treatment, including p85α, MEK, and CDK4, suggesting that 208 induces cell cycle arrest and apoptosis through the p85α/MEK-mediated pathway in U937 cells. Moreover, biological function analysis showed that the combined epigenetic inhibition influenced various processes, including the synthesis and processing of RNA, translation, protein transport, and DNA repair. These findings provide novel insight into the potential mechanisms of multifunctional epigenetic inhibitors, which supports their further improvement and development.
2019, 30(6): 1237-1240
doi: 10.1016/j.cclet.2019.04.033
Abstract:
Most organic reactions require the usage of volatile organic compounds in the synthesis, work-up and purification processes, thus resulting in major environmental pollution and high manufacturing cost. By using cheap biomass lactic acid as the reaction media and catalyst, a sustainable protocol for the synthesis of Z-3-selenocyanatoacrylates and analogues through green selenocyanation of activated alkynes has been achieved. A principal advantage of this protocol is that the usage of organic volatile compounds can be avoided entirely, as the conversion of substrate is almost quantitative or quantitative with a minimal amount of lactic acid employed as reaction media, and the pure products can be conveniently collected through water precipitation.
Most organic reactions require the usage of volatile organic compounds in the synthesis, work-up and purification processes, thus resulting in major environmental pollution and high manufacturing cost. By using cheap biomass lactic acid as the reaction media and catalyst, a sustainable protocol for the synthesis of Z-3-selenocyanatoacrylates and analogues through green selenocyanation of activated alkynes has been achieved. A principal advantage of this protocol is that the usage of organic volatile compounds can be avoided entirely, as the conversion of substrate is almost quantitative or quantitative with a minimal amount of lactic acid employed as reaction media, and the pure products can be conveniently collected through water precipitation.
2019, 30(6): 1241-1243
doi: 10.1016/j.cclet.2019.03.019
Abstract:
Current studies on the oxidative C-H functionalization of benzylic ethers for C-C forging process dominantly focus on primary ethers. The corresponding reaction of secondary ethers remains underdeveloped. Herein, a practical and efficient oxidative C-H cyanation of secondary benzylic ethers with TMSCN in the presence of DDQ is described. The metal-free process is well tolerated with a wide variety of electronically varied α-monosubstituted isochromans, facilely furnishing a library of isochromans bearing α-aryl α-cyano substituent patterns for further diversification and bioactive small molecule identification.
Current studies on the oxidative C-H functionalization of benzylic ethers for C-C forging process dominantly focus on primary ethers. The corresponding reaction of secondary ethers remains underdeveloped. Herein, a practical and efficient oxidative C-H cyanation of secondary benzylic ethers with TMSCN in the presence of DDQ is described. The metal-free process is well tolerated with a wide variety of electronically varied α-monosubstituted isochromans, facilely furnishing a library of isochromans bearing α-aryl α-cyano substituent patterns for further diversification and bioactive small molecule identification.
2019, 30(6): 1244-1248
doi: 10.1016/j.cclet.2019.03.049
Abstract:
MCM-41 material was modified by polyethyleneimine (PEI) using ultrasonic assisted impregnation method with different PEI loading (P-MCM-x, x=0-15 wt%). The synthesised P-MCM-x materials and corresponding Zn/P-MCM-x catalysts were characterised by FTIR, XRD, TEM, BET, XPS, TG and H2-TPR, as well as their catalytic performance in the hydration of acetylene was investigated. The results showed that the modified materials retained the mesoporous structure with good thermostability, and the corresponding Zn/P-MCM-x displayed the higher catalytic performance than that of Zn/MCM-41 catalyst, especially for the Zn/P-MCM-12 catalyst with about 88% C2H2 conversion and 85% selectivity, and the optimal content of PEI is 12 wt%. More importantly, the introduction of PEI enhanced metal-support interaction to make the better metal dispersion and more active sites, and the charge transfer from N atom to Zn species. These all would be responsible for the high activity of the modified Zn catalysts in the acetylene hydration.
MCM-41 material was modified by polyethyleneimine (PEI) using ultrasonic assisted impregnation method with different PEI loading (P-MCM-x, x=0-15 wt%). The synthesised P-MCM-x materials and corresponding Zn/P-MCM-x catalysts were characterised by FTIR, XRD, TEM, BET, XPS, TG and H2-TPR, as well as their catalytic performance in the hydration of acetylene was investigated. The results showed that the modified materials retained the mesoporous structure with good thermostability, and the corresponding Zn/P-MCM-x displayed the higher catalytic performance than that of Zn/MCM-41 catalyst, especially for the Zn/P-MCM-12 catalyst with about 88% C2H2 conversion and 85% selectivity, and the optimal content of PEI is 12 wt%. More importantly, the introduction of PEI enhanced metal-support interaction to make the better metal dispersion and more active sites, and the charge transfer from N atom to Zn species. These all would be responsible for the high activity of the modified Zn catalysts in the acetylene hydration.
2019, 30(6): 1249-1252
doi: 10.1016/j.cclet.2019.03.055
Abstract:
Adenosine triphosphate plays a crucial role in regulation of many biological pathways and has been used as an indicator for many diseases. In this paper, based on the fact that β-cyclodextrin polymer (polyβ-CD) could significantly enhance pyrene fluorescence through supramolecular assembly (host-gest interaction), a sensitive and facile method for adenosine triphosphate detection has been developed. A 3'-pyrene-labelled ATP-binding aptamer was employed as the fluorescence probe, which could be digested by exonuclease Ⅰ to obtain mononucleotides, with pyrene attached on. The pyrene attached on mononucleotides could easily enter the hydrophobic cavity of polyβ-CD, accompanied with prominent fluorescence enhancement. While ATP was introduced, ATP and its aptamer could combine together and the obtained hairpin complex could not be cleaved by exonuclease Ⅰ. The pyrene labelled on the probe could not enter the cavity of polyβ-CD belong to the complex' steric hindrance, accompanied with the weak pyrene' fluorescence. So we could quantify the concentration of adenosine triphosphate facilely by measuring the fluorescence intensity of the system. The detection limit of this method for adenosine triphosphate was 11 μmol/L (S/N=3). The developed method showed sufficient selectivity and could successfully assay adenosine triphosphate in biological samples. The developed method provides a potential platform for biological micromoles assay.
Adenosine triphosphate plays a crucial role in regulation of many biological pathways and has been used as an indicator for many diseases. In this paper, based on the fact that β-cyclodextrin polymer (polyβ-CD) could significantly enhance pyrene fluorescence through supramolecular assembly (host-gest interaction), a sensitive and facile method for adenosine triphosphate detection has been developed. A 3'-pyrene-labelled ATP-binding aptamer was employed as the fluorescence probe, which could be digested by exonuclease Ⅰ to obtain mononucleotides, with pyrene attached on. The pyrene attached on mononucleotides could easily enter the hydrophobic cavity of polyβ-CD, accompanied with prominent fluorescence enhancement. While ATP was introduced, ATP and its aptamer could combine together and the obtained hairpin complex could not be cleaved by exonuclease Ⅰ. The pyrene labelled on the probe could not enter the cavity of polyβ-CD belong to the complex' steric hindrance, accompanied with the weak pyrene' fluorescence. So we could quantify the concentration of adenosine triphosphate facilely by measuring the fluorescence intensity of the system. The detection limit of this method for adenosine triphosphate was 11 μmol/L (S/N=3). The developed method showed sufficient selectivity and could successfully assay adenosine triphosphate in biological samples. The developed method provides a potential platform for biological micromoles assay.
2019, 30(6): 1253-1260
doi: 10.1016/j.cclet.2019.02.009
Abstract:
A novel three-dimensional (3D) layered MoS2@graphene functionalized with nitrogen-doped graphene quantum dots (MoS2@N-GQDs-GR) composites as an enhanced electrochemical hydrogen evolution catalyst. The few layered MoS2 nanoflowers supported on N-GQDs-GR surface were elaborately fabricated by one-pot hydrothermal method, which MoS2 and N-GQDs-GR exist in a bonding manner of Mo-N. In addition, due to the layered MoS2 sheet edge exposes more hydrogen evolution active sites and N-GQDs-GR have high conductivity, the composites exhibit prominent electrocatalytic activity with a low overpotential 99 mV, a small Tafel slope 49.3 mV/dec. Therefore, that the current work will develop HER catalysts may replace Pt.
A novel three-dimensional (3D) layered MoS2@graphene functionalized with nitrogen-doped graphene quantum dots (MoS2@N-GQDs-GR) composites as an enhanced electrochemical hydrogen evolution catalyst. The few layered MoS2 nanoflowers supported on N-GQDs-GR surface were elaborately fabricated by one-pot hydrothermal method, which MoS2 and N-GQDs-GR exist in a bonding manner of Mo-N. In addition, due to the layered MoS2 sheet edge exposes more hydrogen evolution active sites and N-GQDs-GR have high conductivity, the composites exhibit prominent electrocatalytic activity with a low overpotential 99 mV, a small Tafel slope 49.3 mV/dec. Therefore, that the current work will develop HER catalysts may replace Pt.
2019, 30(6): 1261-1265
doi: 10.1016/j.cclet.2018.12.030
Abstract:
The exposed crystal facet of TiO2 is a crucial factor influencing the gas sensing properties. TiO2 with highenergy {001} crystal facets that have higher surface energy and reactivity is expected to exhibit excellent gas-sensing properties. In this paper, TiO2 nanoplates with defective {001} facets were synthesized by chemical etching via one-step hydrothermal method. We carefully explored the gas-sensing performance of TiO2 nanoplates with defective and complete {001} facets towards acetone. The results show that the sensing response of TiO2 nanoplates with complete {001} facets is 70% higher than that of defective TiO2 nanoplates, which proves that the {001} facets plays a vital role in improving the gas sensing performance of TiO2. It is speculated that the poor gas sensitivity of defective TiO2 can be contributed to fewer adsorption sites and blocked electron transfer. This work presents a more direct evidence for explaining the important role of the complete {001} crystal facets in high sensitivity of TiO2 and also provides a new insight for preparing high sensitivity sensing materials.
The exposed crystal facet of TiO2 is a crucial factor influencing the gas sensing properties. TiO2 with highenergy {001} crystal facets that have higher surface energy and reactivity is expected to exhibit excellent gas-sensing properties. In this paper, TiO2 nanoplates with defective {001} facets were synthesized by chemical etching via one-step hydrothermal method. We carefully explored the gas-sensing performance of TiO2 nanoplates with defective and complete {001} facets towards acetone. The results show that the sensing response of TiO2 nanoplates with complete {001} facets is 70% higher than that of defective TiO2 nanoplates, which proves that the {001} facets plays a vital role in improving the gas sensing performance of TiO2. It is speculated that the poor gas sensitivity of defective TiO2 can be contributed to fewer adsorption sites and blocked electron transfer. This work presents a more direct evidence for explaining the important role of the complete {001} crystal facets in high sensitivity of TiO2 and also provides a new insight for preparing high sensitivity sensing materials.
2019, 30(6): 1266-1268
doi: 10.1016/j.cclet.2019.01.002
Abstract:
In this paper, we exploited a unique procedure for obtaining thorny gold nanoparticles (Au NPs) with controllable length of thorns without using seeds and surfactants. A larger number of Ag+ ions was added into the reaction system containing with HAuCl4 and NH2OH·HCl, so as to forming colloidal AgCl. AgCl could induce the growth of thorny Au NPs. The morphology of Au NPs changed from short-thorns, long-thorns to no-thorns, as the amount of AgNO3 increased. The obtained Au NPs exhibited shape-determined surface-enhanced Raman spectroscopy (SERS) activity toward rhodamine 6G (R6G), indicating their potential for use in SERS-based detections and analysis.
In this paper, we exploited a unique procedure for obtaining thorny gold nanoparticles (Au NPs) with controllable length of thorns without using seeds and surfactants. A larger number of Ag+ ions was added into the reaction system containing with HAuCl4 and NH2OH·HCl, so as to forming colloidal AgCl. AgCl could induce the growth of thorny Au NPs. The morphology of Au NPs changed from short-thorns, long-thorns to no-thorns, as the amount of AgNO3 increased. The obtained Au NPs exhibited shape-determined surface-enhanced Raman spectroscopy (SERS) activity toward rhodamine 6G (R6G), indicating their potential for use in SERS-based detections and analysis.
2019, 30(6): 1269-1272
doi: 10.1016/j.cclet.2019.01.007
Abstract:
The smallest cyclic ammonium salt reported to date, N, N-dimethylpyrrolidinium tetrafluoroborate (P11-BF4), was successively synthesized using a synthesis route without metal ions and halogen ions, then investigated as the electrolyte with Propylene carbonate in EDLCs. The electrochemical characteristics of EDLCs assembled by 1 mol/L P11-BF4/PC paired with activated carbon electrodes were compared to traditional electrolytes. P11-BF4 has proven to have superior voltage resistance by using cyclic voltammetry and constant current charge-discharge testing. Moreover, P11-BF4 exhibits a more brilliant rate performance due to its high conductivity. These results demonstrate that P11-BF4 is an ideal electrolyte to improve the energy density and power density of supercapacitors.
The smallest cyclic ammonium salt reported to date, N, N-dimethylpyrrolidinium tetrafluoroborate (P11-BF4), was successively synthesized using a synthesis route without metal ions and halogen ions, then investigated as the electrolyte with Propylene carbonate in EDLCs. The electrochemical characteristics of EDLCs assembled by 1 mol/L P11-BF4/PC paired with activated carbon electrodes were compared to traditional electrolytes. P11-BF4 has proven to have superior voltage resistance by using cyclic voltammetry and constant current charge-discharge testing. Moreover, P11-BF4 exhibits a more brilliant rate performance due to its high conductivity. These results demonstrate that P11-BF4 is an ideal electrolyte to improve the energy density and power density of supercapacitors.
2019, 30(6): 1273-1276
doi: 10.1016/j.cclet.2019.01.024
Abstract:
A high-nuclear Co-V-O cluster was firstly isolated by lacunary polyoxoanion, resulting in the high-nuclear mixed metal-oxo cluster-containing polyoxometalate (POM), K4Na28[{Co4(O-H)3(VO4)}4(SiW9O34)4]·66H2O (1). In 1, the {Co4(O-H)3(VO4)}4 {Co16-V4} core, composed of a {Co4O4} cubane, four {Co4(OH)3} qusi-cubanes and four VO4 units, was stabilized by four lacunary A-α-{SiW9O34} units. Photocatalytic study reveals that 1 exhibits excellent photocatalytic activity for CO2-to-CO conversion with high selectivity under visible light irradiation. The turnover number (TON) and turnover frequency (TOF) reaches as high as 10492 and 0.29 s-1, respectively. Compound 1 represents the first high nuclear TM cluster-containing POM (TM=transition-metal) with efficient visible light catalytic activity for CO2 reduction, and its photocatalytic activity is much higher than those of most reported molecular catalysts. Photoluminescence spectroscopy study reveals that photoexcitation of Ru-photosensitizer is followed by an efficient electron transfer to POMs to reduce CO2.
A high-nuclear Co-V-O cluster was firstly isolated by lacunary polyoxoanion, resulting in the high-nuclear mixed metal-oxo cluster-containing polyoxometalate (POM), K4Na28[{Co4(O-H)3(VO4)}4(SiW9O34)4]·66H2O (1). In 1, the {Co4(O-H)3(VO4)}4 {Co16-V4} core, composed of a {Co4O4} cubane, four {Co4(OH)3} qusi-cubanes and four VO4 units, was stabilized by four lacunary A-α-{SiW9O34} units. Photocatalytic study reveals that 1 exhibits excellent photocatalytic activity for CO2-to-CO conversion with high selectivity under visible light irradiation. The turnover number (TON) and turnover frequency (TOF) reaches as high as 10492 and 0.29 s-1, respectively. Compound 1 represents the first high nuclear TM cluster-containing POM (TM=transition-metal) with efficient visible light catalytic activity for CO2 reduction, and its photocatalytic activity is much higher than those of most reported molecular catalysts. Photoluminescence spectroscopy study reveals that photoexcitation of Ru-photosensitizer is followed by an efficient electron transfer to POMs to reduce CO2.
2019, 30(6): 1277-1281
doi: 10.1016/j.cclet.2019.01.010
Abstract:
Poly(3-hexylthiophene) (P3HT) is a low-cost polymer donor for organic solar cells (OSCs). However, the P3HT-based OSCs usually give low power conversion efficiencies (PCEs) due to the wide bandgap and the high-lying energy levels of P3HT. To solve this problem, in this work, we design and synthesize a new A-D-A type non-fullerene acceptor, DFPCBR, which owns an electron-donating (D) core constructed by linking a 2, 5-difluorobenzene ring with two cyclopentadithiophene moieties, and two electronaccepting (A) end-groups of benzo[c] [1, 2, 5]thiadiazole connected with 3-ethyl-2-thioxothiazolidin-4-one. Because of the strong electron-donating ability and large conjugation effect of D core, DFPCBR shows appropriate energy levels and a narrow bandgap matching well with those of P3HT. Therefore, with P3HT as the donor and DFPCBR as the acceptor, the OSCs possess broad absorption range from 350 nm to 780 nm and the reduced energy loss (Eloss) of 0.79 eV (compared with~1.40 eV for the P3HT:PC61BM device), providing a good PCE of 5.34% with a high open-circuit voltage (VOC) of 0.80 V. Besides, we observe that the photovoltaic performances of these devices are insensitive to the thickness of the active layers:even if the active layer is as thick as 320 nm, ~80% of the best PCE is maintained, which is rarely reported for fullerene-free P3HT-based OSCs, suggesting that DFPCBR has the potential application in commercial OSCs in the future.
Poly(3-hexylthiophene) (P3HT) is a low-cost polymer donor for organic solar cells (OSCs). However, the P3HT-based OSCs usually give low power conversion efficiencies (PCEs) due to the wide bandgap and the high-lying energy levels of P3HT. To solve this problem, in this work, we design and synthesize a new A-D-A type non-fullerene acceptor, DFPCBR, which owns an electron-donating (D) core constructed by linking a 2, 5-difluorobenzene ring with two cyclopentadithiophene moieties, and two electronaccepting (A) end-groups of benzo[c] [1, 2, 5]thiadiazole connected with 3-ethyl-2-thioxothiazolidin-4-one. Because of the strong electron-donating ability and large conjugation effect of D core, DFPCBR shows appropriate energy levels and a narrow bandgap matching well with those of P3HT. Therefore, with P3HT as the donor and DFPCBR as the acceptor, the OSCs possess broad absorption range from 350 nm to 780 nm and the reduced energy loss (Eloss) of 0.79 eV (compared with~1.40 eV for the P3HT:PC61BM device), providing a good PCE of 5.34% with a high open-circuit voltage (VOC) of 0.80 V. Besides, we observe that the photovoltaic performances of these devices are insensitive to the thickness of the active layers:even if the active layer is as thick as 320 nm, ~80% of the best PCE is maintained, which is rarely reported for fullerene-free P3HT-based OSCs, suggesting that DFPCBR has the potential application in commercial OSCs in the future.
2019, 30(6): 1282-1288
doi: 10.1016/j.cclet.2019.02.032
Abstract:
Flexible electrochemical power sources are attracting increasing attentions for their unique advantages like flexibility, shape diversity, light weight and excellent mechanical properties. In this research, we discover that the current collector can dramatically affect the performance of flexible electrochemical power sources with large size. For flexible air-breathing proton exchange membrane fuel cell (PEMFC), the performance could have more than 8 times increase by only adjusting the directions of current collectors. The different performances of different current collection types are mainly attributed to the diverse lengths of the electron transfer pathways. In addition, the conductivity of current collector can dramatically affect the capability of flexible PEMFCs with large-size. The flexible PEMFCs with thicker carbon nanotube membrane as current collector (low electric resistance) show higher ability. A mathematic model is successfully built in this work to further understand the performance. Moreover, the model and simulation are also applicable to other flexible power sources, such as flexible Li-ion battery and supercapacitor.
Flexible electrochemical power sources are attracting increasing attentions for their unique advantages like flexibility, shape diversity, light weight and excellent mechanical properties. In this research, we discover that the current collector can dramatically affect the performance of flexible electrochemical power sources with large size. For flexible air-breathing proton exchange membrane fuel cell (PEMFC), the performance could have more than 8 times increase by only adjusting the directions of current collectors. The different performances of different current collection types are mainly attributed to the diverse lengths of the electron transfer pathways. In addition, the conductivity of current collector can dramatically affect the capability of flexible PEMFCs with large-size. The flexible PEMFCs with thicker carbon nanotube membrane as current collector (low electric resistance) show higher ability. A mathematic model is successfully built in this work to further understand the performance. Moreover, the model and simulation are also applicable to other flexible power sources, such as flexible Li-ion battery and supercapacitor.
2019, 30(6): 1289-1292
doi: 10.1016/j.cclet.2019.02.027
Abstract:
Organic ionic plastic crystals (OIPCs) composed of 1-ethyl-1-methyl pyrrolidinium bis(fluorosulfonyl) imide (P12FSI) and lithium bis(fluorosulfonyl)imide (LiFSI) was used as electrolyte for lithium-oxygen batteries. Since P12FSI-LiFSI electrolyte exhibited high ionic conductivity, good chemical stability and wide electrochemical window, the battery showed good rate capability, excellent cycling stability and can be operated stably for 320 cycles under a fixed capacity of 500 mAh/gcarbon. The use of OIPCs electrolyte could provide a new avenue for the development of high-performance Li-O2 batteries.
Organic ionic plastic crystals (OIPCs) composed of 1-ethyl-1-methyl pyrrolidinium bis(fluorosulfonyl) imide (P12FSI) and lithium bis(fluorosulfonyl)imide (LiFSI) was used as electrolyte for lithium-oxygen batteries. Since P12FSI-LiFSI electrolyte exhibited high ionic conductivity, good chemical stability and wide electrochemical window, the battery showed good rate capability, excellent cycling stability and can be operated stably for 320 cycles under a fixed capacity of 500 mAh/gcarbon. The use of OIPCs electrolyte could provide a new avenue for the development of high-performance Li-O2 batteries.
2019, 30(6): 1293-1296
doi: 10.1016/j.cclet.2019.03.032
Abstract:
Photodynamic therapy (PDT) is an attractive clinical technique for cancer treatment. However, the poor solubility and weak cellular internalization of the molecule-photosensitizers, as well as the exceedingly short lifetime and limited diffusion distance of the generated reactive oxygen species (ROS) in cytoplasm directly restricted the therapeutic efficiency of conventional PDT. In this study, we proposed a facile strategy for improving PDT of cancer based on a mitochondria-targeted nanophotosensitizer. The molecule-photosensitizer chlorin e6 was covalently attached on the internal and external surfaces of the mesoporous silica nanoparticles. Then, the triphenylphosphonium was anchored on the nanoparticles for selectively targeting mitochondria. When irradiated with laser, the nanophotosensitizer can generate a large amount of ROS in mitochondria, thus causing the mitochondrial dysfunction and irreversible cell apoptosis. In vitro and in vivo studies demonstrated that the nanophotosensitizer could boost the treatment efficiency against cancer cells and xenograft tumor models.
Photodynamic therapy (PDT) is an attractive clinical technique for cancer treatment. However, the poor solubility and weak cellular internalization of the molecule-photosensitizers, as well as the exceedingly short lifetime and limited diffusion distance of the generated reactive oxygen species (ROS) in cytoplasm directly restricted the therapeutic efficiency of conventional PDT. In this study, we proposed a facile strategy for improving PDT of cancer based on a mitochondria-targeted nanophotosensitizer. The molecule-photosensitizer chlorin e6 was covalently attached on the internal and external surfaces of the mesoporous silica nanoparticles. Then, the triphenylphosphonium was anchored on the nanoparticles for selectively targeting mitochondria. When irradiated with laser, the nanophotosensitizer can generate a large amount of ROS in mitochondria, thus causing the mitochondrial dysfunction and irreversible cell apoptosis. In vitro and in vivo studies demonstrated that the nanophotosensitizer could boost the treatment efficiency against cancer cells and xenograft tumor models.
Structural tuning of coordination polymers by 4-connecting metal node and secondary building process
2019, 30(6): 1297-1301
doi: 10.1016/j.cclet.2019.02.001
Abstract:
Five transition metal coordination polymers, {[Cu(4-pmntd)2(NO3)2]·2CHCl3}n(1), {[Cu(4-pmntd)2(NO3)2]·3C7H8}n (2), {[Cu(4-pmntd)2(CF3SO3)(H2O)]·CF3SO3·H2O·CH3OH}n (3), [Cd(4-pmntd)2]n·nSiF6·x(CH3OH)·y(CHCl3) (4)and[Zn(4-pmntd)2(CF3SO3)2]n·χ(solvent) (5), have been obtained from a ditopic ligand, N, N'-bis(4-pyridylmethyl)naphthalene diimide (4-pmntd). Either sql-or dia-structures are generated from four connecting coordination nodes of the metal centers. While delicate interpenetration and structural tuning in these complexes is achieved by the different conformations and spatially extending geometries adopted by the ligand and "secondary building process" induced by pillar-like anions.
Five transition metal coordination polymers, {[Cu(4-pmntd)2(NO3)2]·2CHCl3}n(1), {[Cu(4-pmntd)2(NO3)2]·3C7H8}n (2), {[Cu(4-pmntd)2(CF3SO3)(H2O)]·CF3SO3·H2O·CH3OH}n (3), [Cd(4-pmntd)2]n·nSiF6·x(CH3OH)·y(CHCl3) (4)and[Zn(4-pmntd)2(CF3SO3)2]n·χ(solvent) (5), have been obtained from a ditopic ligand, N, N'-bis(4-pyridylmethyl)naphthalene diimide (4-pmntd). Either sql-or dia-structures are generated from four connecting coordination nodes of the metal centers. While delicate interpenetration and structural tuning in these complexes is achieved by the different conformations and spatially extending geometries adopted by the ligand and "secondary building process" induced by pillar-like anions.
2019, 30(6): 1302-1306
doi: 10.1016/j.cclet.2019.02.023
Abstract:
The secondary structural changes of bovine serum albumin (BSA) aqueous solutions with and without calcium cations were investigated by attenuated total reflection-Fourier transform infrared (ATR-FTIR) technology. The spectra of BSA solution and BSA dry powder were mainly reflected the formation of hydrogen bonds between water and BSA. Further investigation indicated that the concentrations of calcium cations in BSA aqueous solution also affected the secondary structural change of the protein. Amide I band was red shifted and amide Ⅱ band was blue shifted in aqueous environment compared with the dry BSA powder, and the addition of calcium cations further changed the amide bands position, which led to the change of the secondary structure. The result was coinciding with the Raman spectroscopy.
The secondary structural changes of bovine serum albumin (BSA) aqueous solutions with and without calcium cations were investigated by attenuated total reflection-Fourier transform infrared (ATR-FTIR) technology. The spectra of BSA solution and BSA dry powder were mainly reflected the formation of hydrogen bonds between water and BSA. Further investigation indicated that the concentrations of calcium cations in BSA aqueous solution also affected the secondary structural change of the protein. Amide I band was red shifted and amide Ⅱ band was blue shifted in aqueous environment compared with the dry BSA powder, and the addition of calcium cations further changed the amide bands position, which led to the change of the secondary structure. The result was coinciding with the Raman spectroscopy.
2019, 30(6): 1307-1309
doi: 10.1016/j.cclet.2019.02.026
Abstract:
A modified ELISA realizing fluorescent and colorimetric immunoassay of nuclear matrix protein 22 (NMP 22) was developed based on porous Pd nanoparticles. The unique structure and excellent enzyme mimetic activity of porous Pd nanoparticles favor to oxidize o-phenylenediamine (OPD) into 2, 3-phenazinediamine (oxOPD) by H2O2, producing colorimetric and fluorescence dual-readout signal for the detection of NMP 22. The developed immunoassay method will offer great potential in clinical research and diagnostic applications.
A modified ELISA realizing fluorescent and colorimetric immunoassay of nuclear matrix protein 22 (NMP 22) was developed based on porous Pd nanoparticles. The unique structure and excellent enzyme mimetic activity of porous Pd nanoparticles favor to oxidize o-phenylenediamine (OPD) into 2, 3-phenazinediamine (oxOPD) by H2O2, producing colorimetric and fluorescence dual-readout signal for the detection of NMP 22. The developed immunoassay method will offer great potential in clinical research and diagnostic applications.
2019, 30(6): 1310-1314
doi: 10.1016/j.cclet.2019.02.029
Abstract:
A copper-centred metal-organic framework material MOF-101 with 2-bromine terephthalic acid as ligands was synthesized by solvothermal method at 70℃ and modified by loading Ag+ to improve the selective adsorption performance. The MOF-101 and Ag+/MOF-101 prepared were characterised by powder X-ray diffraction, X-ray fluorescence, Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis. The adsorptive desulphurisation was quantified by adsorbing dibenzothiophene (DBT) from model oils. The loading of Ag+ enhanced the deep adsorptive desulfurization capacity for DBTand significantly weaken the adsorption competitiveness of toluene. As a result, the DBT concentration of model oil was reduced from 50 ppmS to 10.2 ppmS. Possible understandings were put forward to explain the adsorption performance of Ag+/MOF-101. The kinetics and isotherm data can be well-described by the pseudo-second-order kinetic model and the Langmuir model.
A copper-centred metal-organic framework material MOF-101 with 2-bromine terephthalic acid as ligands was synthesized by solvothermal method at 70℃ and modified by loading Ag+ to improve the selective adsorption performance. The MOF-101 and Ag+/MOF-101 prepared were characterised by powder X-ray diffraction, X-ray fluorescence, Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis. The adsorptive desulphurisation was quantified by adsorbing dibenzothiophene (DBT) from model oils. The loading of Ag+ enhanced the deep adsorptive desulfurization capacity for DBTand significantly weaken the adsorption competitiveness of toluene. As a result, the DBT concentration of model oil was reduced from 50 ppmS to 10.2 ppmS. Possible understandings were put forward to explain the adsorption performance of Ag+/MOF-101. The kinetics and isotherm data can be well-described by the pseudo-second-order kinetic model and the Langmuir model.
2019, 30(6): 1315-1319
doi: 10.1016/j.cclet.2019.02.031
Abstract:
Renewable biomass-derived activated carbons have attracted attentions for supercapacitor applications. Rice husk is a kind of abundant biomass, which has been studied for the preparation of hierarchical activated carbons. Rice husk is rich in silica. Silica in rice husk affects the formation of pore structure in the KOH activation process, which further affects the electrochemical performance of the resultant activated carbon for supercapacitors. In this paper, the effects of silica in rice husk on the activation process were investigated. When the silica in rice husk is not removed, KOH preferentially reacts with silica to produce silicate, which hinders the formation and enlargement of mesopores; the obtained activated carbon exhibits high microporous ratio, high specific area (up to 3263 m2/g), high specific capacitance (315 F/g at 0.5 A/g), but poor rate capability (51.7% capacitance retention with increasing the current density from 0.5 A/g to 20 A/g). When the silica in rice husk is removed, the pores produced by the removal of silica are etched to mesopores in activation process; the obtained activated carbon exhibits high mesoporous ratio, relative high specific surface area of 2804 m2/g and relative high capacitance of 278 F/g at 0.5 A/g with excellent rate capability (76.6% capacitance retention with increasing the current density from 0.5 A/g to 20 A/g).
Renewable biomass-derived activated carbons have attracted attentions for supercapacitor applications. Rice husk is a kind of abundant biomass, which has been studied for the preparation of hierarchical activated carbons. Rice husk is rich in silica. Silica in rice husk affects the formation of pore structure in the KOH activation process, which further affects the electrochemical performance of the resultant activated carbon for supercapacitors. In this paper, the effects of silica in rice husk on the activation process were investigated. When the silica in rice husk is not removed, KOH preferentially reacts with silica to produce silicate, which hinders the formation and enlargement of mesopores; the obtained activated carbon exhibits high microporous ratio, high specific area (up to 3263 m2/g), high specific capacitance (315 F/g at 0.5 A/g), but poor rate capability (51.7% capacitance retention with increasing the current density from 0.5 A/g to 20 A/g). When the silica in rice husk is removed, the pores produced by the removal of silica are etched to mesopores in activation process; the obtained activated carbon exhibits high mesoporous ratio, relative high specific surface area of 2804 m2/g and relative high capacitance of 278 F/g at 0.5 A/g with excellent rate capability (76.6% capacitance retention with increasing the current density from 0.5 A/g to 20 A/g).
2019, 30(6): 1320-1324
doi: 10.1016/j.cclet.2019.03.001
Abstract:
Cy5.5-MSA-G250 nanoparticles (CMGNPs) had been proved to have unique advantages for cancer treatment, including excellent photothermal performance, tumor cell-selective cytotoxicity, direct visualization, and good biocompatibility. However, to cellular systems, the CMGNPs are considered as foreign invaders, and the effect of CMGNPs on immunity system is still unknown. Therefore, more efforts are needed to understand the role of CMGNPs on the immunity system. In this study, we attempted to screen the pro-inflammatory responses on RAW264.7 macrophages after treated with the CMGNPs. In vitro experiments clearly showed that CMGNPs not only enhances phagocytosis capacity of RAW264.7 cells, but also promotes M1 polarization, associated with changes in cell morphology and increased expression of inflammatory cytokines. This ability to induce M1 polarization may be beneficial to CMGNPs to achieve better anticancer effects in clinical trials. Moreover, the observed M1 macrophages' polarization triggered by CMGNPs can be abolished after adding TLR4 inhibitor, CLI095, suggesting that TLR4 is involved in CMGNP-induced inflammation.
Cy5.5-MSA-G250 nanoparticles (CMGNPs) had been proved to have unique advantages for cancer treatment, including excellent photothermal performance, tumor cell-selective cytotoxicity, direct visualization, and good biocompatibility. However, to cellular systems, the CMGNPs are considered as foreign invaders, and the effect of CMGNPs on immunity system is still unknown. Therefore, more efforts are needed to understand the role of CMGNPs on the immunity system. In this study, we attempted to screen the pro-inflammatory responses on RAW264.7 macrophages after treated with the CMGNPs. In vitro experiments clearly showed that CMGNPs not only enhances phagocytosis capacity of RAW264.7 cells, but also promotes M1 polarization, associated with changes in cell morphology and increased expression of inflammatory cytokines. This ability to induce M1 polarization may be beneficial to CMGNPs to achieve better anticancer effects in clinical trials. Moreover, the observed M1 macrophages' polarization triggered by CMGNPs can be abolished after adding TLR4 inhibitor, CLI095, suggesting that TLR4 is involved in CMGNP-induced inflammation.
2019, 30(6): 1325-1328
doi: 10.1016/j.cclet.2019.03.006
Abstract:
An efficient solution-processable route employing Pb(Ac)2 as lead source and anti-solvent treatment to achieve fully covered and homogenous perovskite films is reported. The effect of different solution methods and device architectures on the morphologies of perovskite films were systematically investigated. Our results show that the planar perovskite layer fabricated by one-step solution method achieved fully covered and pinhole-free films. Further anti-solvent treatment using chlorobenzene (CB) promoted a perovskite film with highly smooth surfaces and enlarged grain sizes. Device fabricated from CB treated perovskite film achieved a best PCE of 15.80%, in comparison with 14.02% for the untreated device. These results evidently suggest a feasible route towards controlling the crystallization and morphology of planar heterojunction (PHJ) PSCs for improved efficiency.
An efficient solution-processable route employing Pb(Ac)2 as lead source and anti-solvent treatment to achieve fully covered and homogenous perovskite films is reported. The effect of different solution methods and device architectures on the morphologies of perovskite films were systematically investigated. Our results show that the planar perovskite layer fabricated by one-step solution method achieved fully covered and pinhole-free films. Further anti-solvent treatment using chlorobenzene (CB) promoted a perovskite film with highly smooth surfaces and enlarged grain sizes. Device fabricated from CB treated perovskite film achieved a best PCE of 15.80%, in comparison with 14.02% for the untreated device. These results evidently suggest a feasible route towards controlling the crystallization and morphology of planar heterojunction (PHJ) PSCs for improved efficiency.
2019, 30(6): 1329-1334
doi: 10.1016/j.cclet.2019.01.026
Abstract:
Supercapacitors with high energy density and high power density have attracted numerous attentions. Here, we successfully synthesized Ni6MnO8 material by a fast, facile, and cost-effective method, which the area specific capacitance was found to be as high as 1113 mF/cm2 at a current density of 1 mA/cm2. Further, the asymmetric supercapacitor was assembled by using Ni6MnO8 as the positive electrode and graphene as the negative electrode with an operation potential from 0 to 1.4 V. It exhibited an area specific capacitance of 69.1m F/cm2 at 0.5 mA/cm2 and stable cycling performance which presented about 80% capacitance retention after 5000 cycles at 5 mA/cm2. The energy density of graphene//Ni6MnO8 supercapacitors was calculated to be 18.81 mWh/cm2 at a power density of 350.1 mW/cm2 and still remained 5.8 mWh/cm2 at a power density of 6990.7 mW/cm2, meaning that the asymmetric supercapacitor combine excellent power density and energy density.
Supercapacitors with high energy density and high power density have attracted numerous attentions. Here, we successfully synthesized Ni6MnO8 material by a fast, facile, and cost-effective method, which the area specific capacitance was found to be as high as 1113 mF/cm2 at a current density of 1 mA/cm2. Further, the asymmetric supercapacitor was assembled by using Ni6MnO8 as the positive electrode and graphene as the negative electrode with an operation potential from 0 to 1.4 V. It exhibited an area specific capacitance of 69.1m F/cm2 at 0.5 mA/cm2 and stable cycling performance which presented about 80% capacitance retention after 5000 cycles at 5 mA/cm2. The energy density of graphene//Ni6MnO8 supercapacitors was calculated to be 18.81 mWh/cm2 at a power density of 350.1 mW/cm2 and still remained 5.8 mWh/cm2 at a power density of 6990.7 mW/cm2, meaning that the asymmetric supercapacitor combine excellent power density and energy density.
2019, 30(6): 1335-1340
doi: 10.1016/j.cclet.2019.02.019
Abstract:
Gold-based nanomaterials with plasmonic properties exhibit various potentials for biomedical applications. In this work, gold nanoprisms (GNPs) was synthesized and then modified with LyP-1, a tumor-homing peptide, to improve the affinity of the GNPs to tumor cells, thus, to improve the efficacy of tumor-targeted photothermal therapy. The introduction of NIR dye IR780 not only enabled the GNPsbased nanosystem with the surface-enhanced resonant Raman scattering (SERRS) property, but also enhanced the plasmonic photothermal property which delivering therapeutic heating by 660 nm laser irradiation. The obtained GNPs/IR780-LyP-1 presented significantly increased of photothermal conversion in vitro and in vivo, which resulted in enhanced tumor-targeting photothermal therapeutic efficacy after laser irradiation. Hence, the GNPs/IR780-LyP-1 prepared in this study can be served as a Raman-encoded molecular imaging candidate and photothermal therapy agents for future cancer treatment.
Gold-based nanomaterials with plasmonic properties exhibit various potentials for biomedical applications. In this work, gold nanoprisms (GNPs) was synthesized and then modified with LyP-1, a tumor-homing peptide, to improve the affinity of the GNPs to tumor cells, thus, to improve the efficacy of tumor-targeted photothermal therapy. The introduction of NIR dye IR780 not only enabled the GNPsbased nanosystem with the surface-enhanced resonant Raman scattering (SERRS) property, but also enhanced the plasmonic photothermal property which delivering therapeutic heating by 660 nm laser irradiation. The obtained GNPs/IR780-LyP-1 presented significantly increased of photothermal conversion in vitro and in vivo, which resulted in enhanced tumor-targeting photothermal therapeutic efficacy after laser irradiation. Hence, the GNPs/IR780-LyP-1 prepared in this study can be served as a Raman-encoded molecular imaging candidate and photothermal therapy agents for future cancer treatment.
2019, 30(6): 1341-1345
doi: 10.1016/j.cclet.2019.03.005
Abstract:
Alloyed-type anode materials with high-energy density for lithium and sodium ion batteries attracted much attention of the researchers. However, substantial volume expansion of these materials in the devices during repeated electrochemical process leads to fast capacity fading and hinders their further practical application. Nanotechnology could act as a useful tool to effectively address the issue. Herein, lotus-stalk Bi4Ge3O12 nanosheets vertically grown on the nickel foam (denoted as Bi4Ge3O12 NSs@NF) were prepared via a straight-forward solvothermal method. Benefiting from their three dimensional (3D) conductive framework and two dimensional (2D) lotus-stalk Bi4Ge3O12 nanosheet structure, as anode materials of lithium-ion batteries (LIBs) and sodium-ion batteries (NIBs), the electrochemical performances of Bi4Ge3O12 NSs@NF were greatly enhanced as a result of mitigating the huge volume variations during cycles. The Bi4Ge3O12 NSs@NF electrodes delivered a high reversible capacity of 1033.1 mAh/g for the first cycle and exhibited 68.6% capacity retention of after 88 cycles at 0.10 A/g in the voltage window of 0.01~3.0 V versus Li/Li+. In the test of NIBs, the lotus-stalk Bi4Ge3O12 composite electrodes still stored Na+ as high as 332.3 mAh/g at 0.10 A/g over 100 sodiation/desodiation repeating cycles.
Alloyed-type anode materials with high-energy density for lithium and sodium ion batteries attracted much attention of the researchers. However, substantial volume expansion of these materials in the devices during repeated electrochemical process leads to fast capacity fading and hinders their further practical application. Nanotechnology could act as a useful tool to effectively address the issue. Herein, lotus-stalk Bi4Ge3O12 nanosheets vertically grown on the nickel foam (denoted as Bi4Ge3O12 NSs@NF) were prepared via a straight-forward solvothermal method. Benefiting from their three dimensional (3D) conductive framework and two dimensional (2D) lotus-stalk Bi4Ge3O12 nanosheet structure, as anode materials of lithium-ion batteries (LIBs) and sodium-ion batteries (NIBs), the electrochemical performances of Bi4Ge3O12 NSs@NF were greatly enhanced as a result of mitigating the huge volume variations during cycles. The Bi4Ge3O12 NSs@NF electrodes delivered a high reversible capacity of 1033.1 mAh/g for the first cycle and exhibited 68.6% capacity retention of after 88 cycles at 0.10 A/g in the voltage window of 0.01~3.0 V versus Li/Li+. In the test of NIBs, the lotus-stalk Bi4Ge3O12 composite electrodes still stored Na+ as high as 332.3 mAh/g at 0.10 A/g over 100 sodiation/desodiation repeating cycles.
2019, 30(6): 1346-1350
doi: 10.1016/j.cclet.2018.12.025
Abstract:
Heterogeneous catalysis is of tremendous importance to modern industries. Exposed atoms of heterogeneous catalysts are heavily involved in surface processes such as the adsorption, activation, diffusion and reaction of substrate molecules. Surfaces of metal or metal oxide based catalysts are usually taken as hard templates that only undergo limited relaxation during catalytic reactions, especially in theoretical simulations. In this work, by using genetic algorithm (GA) aided density functional theory (DFT) calculations, we studied the surface processes involved in CO oxidation on the Au(100) surface. The use of GA greatly improves the capacity of DFT calculations in locating the potential energy surface (PES) of the surface reactions, and surprisingly, it has been found that the Au(100) surface can undergo drastic reconstruction under the influence of O adsorption and the adapted partially oxidized Au surface exhibits unique activities for subsequent adsorptions and reactions. This work depicts the kinetic nature of the Au (100) surface in its catalyzed reactions and also significantly expands our understanding of how surface atoms act in heterogeneous catalysis.
Heterogeneous catalysis is of tremendous importance to modern industries. Exposed atoms of heterogeneous catalysts are heavily involved in surface processes such as the adsorption, activation, diffusion and reaction of substrate molecules. Surfaces of metal or metal oxide based catalysts are usually taken as hard templates that only undergo limited relaxation during catalytic reactions, especially in theoretical simulations. In this work, by using genetic algorithm (GA) aided density functional theory (DFT) calculations, we studied the surface processes involved in CO oxidation on the Au(100) surface. The use of GA greatly improves the capacity of DFT calculations in locating the potential energy surface (PES) of the surface reactions, and surprisingly, it has been found that the Au(100) surface can undergo drastic reconstruction under the influence of O adsorption and the adapted partially oxidized Au surface exhibits unique activities for subsequent adsorptions and reactions. This work depicts the kinetic nature of the Au (100) surface in its catalyzed reactions and also significantly expands our understanding of how surface atoms act in heterogeneous catalysis.
2019, 30(6): 1186-1189
doi: 10.1016/j.cclet.2019.02.020
Abstract:
Since the commercialization of the fuel cell electric vehicles (FCEVs), the polymer electrolyte membrane fuel cell system has been actively improved as a powertrain for ultimate environment-friendly vehicle. During the FCEV operation, various transient conditions such as start-up/shut-down and fuel starvation occur irregularly, which deteriorates the durability of the membrane electrode assembly. In particular, when fuel starvation occurs, the carbon support in the anode is oxidized within few minutes, thus the mitigation of this phenomenon is essential for securing the durability. This short review introduces the concept of reversal tolerant anode (RTA), which is a mitigation method using an oxygen evolution catalyst and reviews some previous reports. In addition, new approach for RTA suggested by authors recently, which is the replacement of Pt anode catalyst by multifunctional IrRu alloy catalyst that simultaneously exhibits the activities for the hydrogen oxidation reaction and the oxygen evolution reaction is introduced.
Since the commercialization of the fuel cell electric vehicles (FCEVs), the polymer electrolyte membrane fuel cell system has been actively improved as a powertrain for ultimate environment-friendly vehicle. During the FCEV operation, various transient conditions such as start-up/shut-down and fuel starvation occur irregularly, which deteriorates the durability of the membrane electrode assembly. In particular, when fuel starvation occurs, the carbon support in the anode is oxidized within few minutes, thus the mitigation of this phenomenon is essential for securing the durability. This short review introduces the concept of reversal tolerant anode (RTA), which is a mitigation method using an oxygen evolution catalyst and reviews some previous reports. In addition, new approach for RTA suggested by authors recently, which is the replacement of Pt anode catalyst by multifunctional IrRu alloy catalyst that simultaneously exhibits the activities for the hydrogen oxidation reaction and the oxygen evolution reaction is introduced.
2019, 30(6): 1190-1197
doi: 10.1016/j.cclet.2019.03.035
Abstract:
Calixarenes and pillararenes are cyclic oligomers containing repeating units of phenol and methane. The modification of ionized groups bring calixarenes and pillararenes derivates both good water solubility and strong binding affinities towards various organic/inorganic/biological guest molecules in both water and the solid state. Meanwhile, the pre-organized structures of these compounds are indispensable in constructing of stimuli-responsive supramolecular assembly. With these properties, the supramolecular selective binding and molecular assembly based on calixarene/pillararene are widely used in enzyme tandem assay, stimuli-responsive nanostructure, drug delivery, organelle fluorescent imaging, photocontrolled morphological change, organic and inorganic hybrid material, solid tunable photoluminescence and so on. This review summarized the recent research progresses on the calixarene/pillararene-based supramolecular systems and discussed the expectation of the future development.
Calixarenes and pillararenes are cyclic oligomers containing repeating units of phenol and methane. The modification of ionized groups bring calixarenes and pillararenes derivates both good water solubility and strong binding affinities towards various organic/inorganic/biological guest molecules in both water and the solid state. Meanwhile, the pre-organized structures of these compounds are indispensable in constructing of stimuli-responsive supramolecular assembly. With these properties, the supramolecular selective binding and molecular assembly based on calixarene/pillararene are widely used in enzyme tandem assay, stimuli-responsive nanostructure, drug delivery, organelle fluorescent imaging, photocontrolled morphological change, organic and inorganic hybrid material, solid tunable photoluminescence and so on. This review summarized the recent research progresses on the calixarene/pillararene-based supramolecular systems and discussed the expectation of the future development.