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2024 Volume 40 Issue 8
2024, 40(8): 1425-1441
doi: 10.11862/CJIC.20240088
Abstract:
Magic-size clusters (MSCs) have attracted much attention in recent years due to their atomically precise and specialized structures; and their unique electronic and optical properties. They play an important role in the formation and growth of semiconductor nanocrystals. An in-depth understanding of the precise chemical composition, atomic structures, and growth mechanisms of MSCs is essential for researchers to explore their properties from the molecular to the macroscopic level. This review details the formation and growth mechanisms of semiconductor MSCs and explores effective strategies to regulate the morphology of these clusters. At the same time, this paper also combs through the current research status of non-stoichiometric and stoichiometric MSCs. On this basis, the review summarizes the main technical tools currently used to characterize MSCs and discusses potential non-destructive detection techniques. Finally, the paper also outlines the applications of MSCs in various fields and looks forward to future research directions.
Magic-size clusters (MSCs) have attracted much attention in recent years due to their atomically precise and specialized structures; and their unique electronic and optical properties. They play an important role in the formation and growth of semiconductor nanocrystals. An in-depth understanding of the precise chemical composition, atomic structures, and growth mechanisms of MSCs is essential for researchers to explore their properties from the molecular to the macroscopic level. This review details the formation and growth mechanisms of semiconductor MSCs and explores effective strategies to regulate the morphology of these clusters. At the same time, this paper also combs through the current research status of non-stoichiometric and stoichiometric MSCs. On this basis, the review summarizes the main technical tools currently used to characterize MSCs and discusses potential non-destructive detection techniques. Finally, the paper also outlines the applications of MSCs in various fields and looks forward to future research directions.
2024, 40(8): 1442-1451
doi: 10.11862/CJIC.20240114
Abstract:
Abstract: Five dinuclear complexes [Ln(2-pyterpy)(NO3)2(μ-OCH3)]2 (Ln-2-pyterpy, Ln=Pr, Sm, Eu, Dy, Er) were synthesized by solvothermal method using 4′-(2-pyridyl)-2, 2′∶6′, 2″-terpyridine (2-pyterpy) as ligand. Single crystal X-ray diffraction analysis showed that complexes Pr-2-pyterpy and Sm-2-pyterpy are isomorphic and crystallize in monoclinic system, space group P21 with a=0.956 43(19) nm, b=1.965 4(4) nm, c=1.193 5(2) nm, β=90.41(3)°. Complex Er-2-pyterpy crystallizes in monoclinic system, space group C2/c with a=2.838 8(6) nm, b=1.204 8(2) nm, c=1.520 6(3) nm, β=121.70(3)°. Powder X-ray diffraction results showed that complexes Ln-2-pyterpy (Ln=Eu, Dy) are isomorphic and have the same structure as the reported complexes [Ln(2-pyterpy)(NO3)2(μ-OCH3)]2 (Ln=Tb, Dy), crystallizing in monoclinic crystal system, space group P21/n. The lanthanide contraction effect plays an important role in adjusting the structure of this series of complexes. The solid complexes Ln-2-pyterpy (Ln=Pr, Sm, Eu, Dy) emitted the characteristic fluorescence of Ln(Ⅲ) ions. At 300 K, the χMT experimental values of complexes Ln-2-pyterpy (Ln=Pr, Sm, Eu, Dy) were consistent with the theoretical values of two corresponding isolated Ln(Ⅲ) ions. According to the χMT experimental value at 2 K, the weak antiferromagnetic and ferromagnetic coupling effects between the Ln(Ⅲ) ions of the complexes Sm-2-pyterpy and Eu-2-pyterpy are transmitted by methoxy-bridge, respectively. CCDC: 2333490, Pr-2-pyterpy; 2333491, Sm-2-pyterpy; 2333483, Er-2-pyterpy.
Abstract: Five dinuclear complexes [Ln(2-pyterpy)(NO3)2(μ-OCH3)]2 (Ln-2-pyterpy, Ln=Pr, Sm, Eu, Dy, Er) were synthesized by solvothermal method using 4′-(2-pyridyl)-2, 2′∶6′, 2″-terpyridine (2-pyterpy) as ligand. Single crystal X-ray diffraction analysis showed that complexes Pr-2-pyterpy and Sm-2-pyterpy are isomorphic and crystallize in monoclinic system, space group P21 with a=0.956 43(19) nm, b=1.965 4(4) nm, c=1.193 5(2) nm, β=90.41(3)°. Complex Er-2-pyterpy crystallizes in monoclinic system, space group C2/c with a=2.838 8(6) nm, b=1.204 8(2) nm, c=1.520 6(3) nm, β=121.70(3)°. Powder X-ray diffraction results showed that complexes Ln-2-pyterpy (Ln=Eu, Dy) are isomorphic and have the same structure as the reported complexes [Ln(2-pyterpy)(NO3)2(μ-OCH3)]2 (Ln=Tb, Dy), crystallizing in monoclinic crystal system, space group P21/n. The lanthanide contraction effect plays an important role in adjusting the structure of this series of complexes. The solid complexes Ln-2-pyterpy (Ln=Pr, Sm, Eu, Dy) emitted the characteristic fluorescence of Ln(Ⅲ) ions. At 300 K, the χMT experimental values of complexes Ln-2-pyterpy (Ln=Pr, Sm, Eu, Dy) were consistent with the theoretical values of two corresponding isolated Ln(Ⅲ) ions. According to the χMT experimental value at 2 K, the weak antiferromagnetic and ferromagnetic coupling effects between the Ln(Ⅲ) ions of the complexes Sm-2-pyterpy and Eu-2-pyterpy are transmitted by methoxy-bridge, respectively. CCDC: 2333490, Pr-2-pyterpy; 2333491, Sm-2-pyterpy; 2333483, Er-2-pyterpy.
2024, 40(8): 1452-1460
doi: 10.11862/CJIC.20240191
Abstract:
Abstract: Here, we propose a green and self-crosslinking strategy to in-situ prepare a sodium carboxymethylcellulose (CMC) and sodium alginate (SA) layer on the Zn electrode (Zn@SA+CMC) via the superionic bonds between the carboxylate groups and Zn2+. Scanning electron microscopy (SEM) images confirm a porous structure of the SA+CMC layer. The functional effects of the gel layer are as follows. Firstly, the layer is rich in hydroxyl groups, which can be tightly adsorbed onto the Zn anode surface to form a protective layer and separate the Zn anode from the electrolyte. Secondly, the protective layer is a gel film, making it mechanically flexible, which can accommodate the volume change during Zn plating. Thirdly, the SA+CMC gel layer possesses zincophilicity, reduces interfacial resistance, lowers the nucleation energy barrier, and increases ionic conductivity, thereby promoting uniform Zn deposition and effectively inhibiting dendritic growth. As a result, the Zn@SA+CMC symmetrical cell sustained over 890 h of long-term stability at a high current density of 3 mA·cm-2 and the Zn@SA+CMC half cell could provide as high a Coulombic efficiency of 99.8% over 3 700 h (1 850 cycles). Furthermore, the Zn@SA+CMC||MnO2 full cell delivered a specific capacity of 185.1 mAh·g-1 at 0.3 A·g-1, maintaining stability for over 1 200 cycles.
Abstract: Here, we propose a green and self-crosslinking strategy to in-situ prepare a sodium carboxymethylcellulose (CMC) and sodium alginate (SA) layer on the Zn electrode (Zn@SA+CMC) via the superionic bonds between the carboxylate groups and Zn2+. Scanning electron microscopy (SEM) images confirm a porous structure of the SA+CMC layer. The functional effects of the gel layer are as follows. Firstly, the layer is rich in hydroxyl groups, which can be tightly adsorbed onto the Zn anode surface to form a protective layer and separate the Zn anode from the electrolyte. Secondly, the protective layer is a gel film, making it mechanically flexible, which can accommodate the volume change during Zn plating. Thirdly, the SA+CMC gel layer possesses zincophilicity, reduces interfacial resistance, lowers the nucleation energy barrier, and increases ionic conductivity, thereby promoting uniform Zn deposition and effectively inhibiting dendritic growth. As a result, the Zn@SA+CMC symmetrical cell sustained over 890 h of long-term stability at a high current density of 3 mA·cm-2 and the Zn@SA+CMC half cell could provide as high a Coulombic efficiency of 99.8% over 3 700 h (1 850 cycles). Furthermore, the Zn@SA+CMC||MnO2 full cell delivered a specific capacity of 185.1 mAh·g-1 at 0.3 A·g-1, maintaining stability for over 1 200 cycles.
2024, 40(8): 1461-1473
doi: 10.11862/CJIC.20240189
Abstract:
The structural and interfacial instability of high-nickel layered cathode material (NCM811) were improved by the construction of inorganic-organic dual-coating. The dual-coating layer was composed of nano lithium metaluminate (LiAlO2, LAO) and cyclopolyacrylonitrile (cPAN). The LAO is a typical lithium-ion conductor, which can be used as a surface coating material to ensure rapid Li+ migration at the interface. In addition, the polyacrylonitrile (PAN) undergoes cross-linked cyclization reactions, resulting in the formation of a delocalized π bond and the formation of the cPAN with electronic conductivity after low-temperature heat treatment. The structure and composition of the dual-coating layer were carefully characterized, which indicates its uniform distribution on the surface of the NCM811 material. The as-obtained modified sample showed an electrochemical capacity retention of 84.8% after 150 cycles in the voltage range of 2.7-4.3 V (vs Li/Li+) at the current density of 1C (180 mA·g-1). Under the same test conditions, the capacity retention of pristine NCM811 was only 65.5%. The dual-coating layer can effectively protect the active material and could reduce the electrolyte decomposition on the material surface to a certain extent, leading to a decrease in interfacial impedance.
The structural and interfacial instability of high-nickel layered cathode material (NCM811) were improved by the construction of inorganic-organic dual-coating. The dual-coating layer was composed of nano lithium metaluminate (LiAlO2, LAO) and cyclopolyacrylonitrile (cPAN). The LAO is a typical lithium-ion conductor, which can be used as a surface coating material to ensure rapid Li+ migration at the interface. In addition, the polyacrylonitrile (PAN) undergoes cross-linked cyclization reactions, resulting in the formation of a delocalized π bond and the formation of the cPAN with electronic conductivity after low-temperature heat treatment. The structure and composition of the dual-coating layer were carefully characterized, which indicates its uniform distribution on the surface of the NCM811 material. The as-obtained modified sample showed an electrochemical capacity retention of 84.8% after 150 cycles in the voltage range of 2.7-4.3 V (vs Li/Li+) at the current density of 1C (180 mA·g-1). Under the same test conditions, the capacity retention of pristine NCM811 was only 65.5%. The dual-coating layer can effectively protect the active material and could reduce the electrolyte decomposition on the material surface to a certain extent, leading to a decrease in interfacial impedance.
2024, 40(8): 1474-1482
doi: 10.11862/CJIC.20240188
Abstract:
Two new trinuclear Ln-based complexes with the formula [Ln3(dbm)5(L)2(CH3OH)2]·CH2Cl2 (Ln=Pr (1), Ho (2); Hdbm=dibenzoylmethane) have been constructed via the solvothermal method by using a polydentate Schiff base ligand H2L (H2L=(E)-6-(hydroxymethyl)-N′-((6-methoxypyridin-2-yl)methylene)picolinohydrazide) reacting with Ln(dbm)3·2H2O. Single-crystal X-ray diffraction reveals that complexes 1 and 2 are isostructural, and their structures are mainly composed of three Ln(Ⅲ) ions, five dbm- ions, two L2- ions, two coordinated CH3OH molecules, and one lattice CH2Cl2 molecule. The three central Ln(Ⅲ) ions are connected by four μ2-O atoms forming a folded Ln3 core. Notably, complexes 1 and 2 show promising antibacterial activity and exhibit stronger bacteriostatic activities compared to their precursor components. Additionally, their interaction with calf thymus DNA (ctDNA) was studied using ultraviolet spectroscopy, cyclic voltammetry, and fluorescence spectroscopy, demonstrating their ability to bind to ctDNA mainly by intercalation.
Two new trinuclear Ln-based complexes with the formula [Ln3(dbm)5(L)2(CH3OH)2]·CH2Cl2 (Ln=Pr (1), Ho (2); Hdbm=dibenzoylmethane) have been constructed via the solvothermal method by using a polydentate Schiff base ligand H2L (H2L=(E)-6-(hydroxymethyl)-N′-((6-methoxypyridin-2-yl)methylene)picolinohydrazide) reacting with Ln(dbm)3·2H2O. Single-crystal X-ray diffraction reveals that complexes 1 and 2 are isostructural, and their structures are mainly composed of three Ln(Ⅲ) ions, five dbm- ions, two L2- ions, two coordinated CH3OH molecules, and one lattice CH2Cl2 molecule. The three central Ln(Ⅲ) ions are connected by four μ2-O atoms forming a folded Ln3 core. Notably, complexes 1 and 2 show promising antibacterial activity and exhibit stronger bacteriostatic activities compared to their precursor components. Additionally, their interaction with calf thymus DNA (ctDNA) was studied using ultraviolet spectroscopy, cyclic voltammetry, and fluorescence spectroscopy, demonstrating their ability to bind to ctDNA mainly by intercalation.
2024, 40(8): 1483-1490
doi: 10.11862/CJIC.20240093
Abstract:
Fluorescent magnetic gadolinium-doped carbon dots (Gd-CDs) were prepared using a high-temperature carbonization method. The prepared Gd-CDs emitted bright green fluorescence with a fluorescence quantum yield of 32.6% and a T1 relaxation efficiency of up to 9.02 L·mmol-1·s-1. By conjugating with the ovarian cancer-specific antibody Anti-HE4, the resulting Anti-HE4/Gd-CDs nanoprobes could perform specific fluorescent imaging and T1-weighted imaging of SKOV-3 ovarian cancer cells. The fluorescence intensity was proportional to the concentration of SKOV-3 cells, with a detection limit of 658 cell·mL-1. This method was applied to the detection of SKOV-3 cells in blood samples.
Fluorescent magnetic gadolinium-doped carbon dots (Gd-CDs) were prepared using a high-temperature carbonization method. The prepared Gd-CDs emitted bright green fluorescence with a fluorescence quantum yield of 32.6% and a T1 relaxation efficiency of up to 9.02 L·mmol-1·s-1. By conjugating with the ovarian cancer-specific antibody Anti-HE4, the resulting Anti-HE4/Gd-CDs nanoprobes could perform specific fluorescent imaging and T1-weighted imaging of SKOV-3 ovarian cancer cells. The fluorescence intensity was proportional to the concentration of SKOV-3 cells, with a detection limit of 658 cell·mL-1. This method was applied to the detection of SKOV-3 cells in blood samples.
2024, 40(8): 1491-1500
doi: 10.11862/CJIC.20240086
Abstract:
Protonated g-C3N4 nanorod loaded with Ag (Ag/pCN) materials were prepared. The photocatalytic degradation of methylene blue (MB) solution was compared between g-C3N4 (CN), CN loaded with Ag (Ag/CN), pCN, and Ag/pCN under visible light. Ag/pCN had the highest photocatalytic efficiency of 92.63% and exhibited good stability. The mechanism of photocatalytic degradation of MB by Ag/pCN was investigated through the photocurrent-time (I-t) curve, Nyquist curve, Mott-Schokkty curve, and capture experiment. Although the π conjugated system of pCN was disrupted, the synergistic effect of forming nanorods, increasing specific surface area, and loading Ag resulted in the excellent photocatalytic performance of Ag/pCN. Hydroxyl radicals (·OH) are the main active substances in the photocatalytic process. The active substance ·OH is produced by the reaction of photo-generated electrons (e-) with O2, as well as photo-generated holes (h+) with H2O or OH-.
Protonated g-C3N4 nanorod loaded with Ag (Ag/pCN) materials were prepared. The photocatalytic degradation of methylene blue (MB) solution was compared between g-C3N4 (CN), CN loaded with Ag (Ag/CN), pCN, and Ag/pCN under visible light. Ag/pCN had the highest photocatalytic efficiency of 92.63% and exhibited good stability. The mechanism of photocatalytic degradation of MB by Ag/pCN was investigated through the photocurrent-time (I-t) curve, Nyquist curve, Mott-Schokkty curve, and capture experiment. Although the π conjugated system of pCN was disrupted, the synergistic effect of forming nanorods, increasing specific surface area, and loading Ag resulted in the excellent photocatalytic performance of Ag/pCN. Hydroxyl radicals (·OH) are the main active substances in the photocatalytic process. The active substance ·OH is produced by the reaction of photo-generated electrons (e-) with O2, as well as photo-generated holes (h+) with H2O or OH-.
2024, 40(8): 1501-1510
doi: 10.11862/CJIC.20240078
Abstract:
Two supramolecular complexes of [Mn2(2, 2′-bipy)4(H2O)Cl3](L1)·6H2O (1) and [Mn(2, 2′-bipy)2(H2O)Cl](L2)·3H2O (2) (L1-=p-methylbenzenesulfonate anion, L2-=m-nitrobenzenesulfonate anion, 2, 2′-bipy=2, 2′-bipyridine) were synthesized by solvothermal method. The complexes were characterized by single-crystal X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, and nitrogen adsorption-desorption test. Using the Mannich reaction as a probe, the catalytic properties of the two complexes were studied, and the effects of the structure of the complexes on their catalytic properties were analyzed by comparing the results of scanning electron microscopy and powder X-ray diffraction. Finally, density functional theory was used to predict the active sites of the complexes, and X-ray photoelectron spectroscopy was used to prove the activation of the active sites. Then the mechanism of Mannich reaction catalyzed by the complexes was clarified.
Two supramolecular complexes of [Mn2(2, 2′-bipy)4(H2O)Cl3](L1)·6H2O (1) and [Mn(2, 2′-bipy)2(H2O)Cl](L2)·3H2O (2) (L1-=p-methylbenzenesulfonate anion, L2-=m-nitrobenzenesulfonate anion, 2, 2′-bipy=2, 2′-bipyridine) were synthesized by solvothermal method. The complexes were characterized by single-crystal X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, and nitrogen adsorption-desorption test. Using the Mannich reaction as a probe, the catalytic properties of the two complexes were studied, and the effects of the structure of the complexes on their catalytic properties were analyzed by comparing the results of scanning electron microscopy and powder X-ray diffraction. Finally, density functional theory was used to predict the active sites of the complexes, and X-ray photoelectron spectroscopy was used to prove the activation of the active sites. Then the mechanism of Mannich reaction catalyzed by the complexes was clarified.
2024, 40(8): 1511-1518
doi: 10.11862/CJIC.20240072
Abstract:
The low-valent germanium compounds with ultra-bulky silylamino groups can construct novel chemical structures and provide new discoveries with academic importance. The two-coordinated ultra-bulky silylamino germylene chloride Ge(N(SiiPr3)2)Cl (1) has an empty 4p-orbital and a lone pair. Two reactions of thermal structural conversion and oxidation addition with phenanthrenequinone on the two activities of 1 were investigated. The thermal decomposition of 1 generated tetragermylene Ge4(NSiiPr3)4 (2) with cubic molecular structure, and its oxidative addition quantitatively with phenanthrenequinone (L) furnished aminomonochlorogermanium(IV) phenanthren-9, 10-diolate: [Ge(N(SiiPr3)2)(L)Cl] (3). Their single-crystal structures and composition were fully characterized. Tetragermylene 2 is essentially a tetrameric adduct of isogermanitrile, its molecular structure exhibits a distorted cubic configuration, and four Ge atoms and four N atoms exist at the eight vertices of the central cubic skeleton. The Ge—N bond length is 0.2036(3) nm, the bond angles of N—Ge—N and Ge—N—Ge are 85.51(18)° and 94.32(16)°, respectively, and the side of the cubic skeleton is close to a planar parallelogram. Theoretical calculation reveals for the first time the bonding of 2. The natural bond orbital (NBO) investigation provided a total of 20 molecular orbitals on the Ge4N4 skeleton. Additionally, the localized orbitals presented three energy levels of -12.22, -15.12, and -20.12 eV, for four Ge lone pairs, 12 Ge—N bonds and four Si—N bonds, respectively. The Ge lone pair mainly remains the 4s character, while the Ge—N bond is contributed by the orbitals of 2s (18.4%) and 2p (71.3%) on N atom, 4s (0.75%) and 4p (9.43%) on Ge atom. In the molecule of 3, the sp3 hybridized GeⅣ is coordinated by four donor atoms and exhibits a distorted tetrahedral configuration, because of the steric hindrance and asymmetric bonding.
The low-valent germanium compounds with ultra-bulky silylamino groups can construct novel chemical structures and provide new discoveries with academic importance. The two-coordinated ultra-bulky silylamino germylene chloride Ge(N(SiiPr3)2)Cl (1) has an empty 4p-orbital and a lone pair. Two reactions of thermal structural conversion and oxidation addition with phenanthrenequinone on the two activities of 1 were investigated. The thermal decomposition of 1 generated tetragermylene Ge4(NSiiPr3)4 (2) with cubic molecular structure, and its oxidative addition quantitatively with phenanthrenequinone (L) furnished aminomonochlorogermanium(IV) phenanthren-9, 10-diolate: [Ge(N(SiiPr3)2)(L)Cl] (3). Their single-crystal structures and composition were fully characterized. Tetragermylene 2 is essentially a tetrameric adduct of isogermanitrile, its molecular structure exhibits a distorted cubic configuration, and four Ge atoms and four N atoms exist at the eight vertices of the central cubic skeleton. The Ge—N bond length is 0.2036(3) nm, the bond angles of N—Ge—N and Ge—N—Ge are 85.51(18)° and 94.32(16)°, respectively, and the side of the cubic skeleton is close to a planar parallelogram. Theoretical calculation reveals for the first time the bonding of 2. The natural bond orbital (NBO) investigation provided a total of 20 molecular orbitals on the Ge4N4 skeleton. Additionally, the localized orbitals presented three energy levels of -12.22, -15.12, and -20.12 eV, for four Ge lone pairs, 12 Ge—N bonds and four Si—N bonds, respectively. The Ge lone pair mainly remains the 4s character, while the Ge—N bond is contributed by the orbitals of 2s (18.4%) and 2p (71.3%) on N atom, 4s (0.75%) and 4p (9.43%) on Ge atom. In the molecule of 3, the sp3 hybridized GeⅣ is coordinated by four donor atoms and exhibits a distorted tetrahedral configuration, because of the steric hindrance and asymmetric bonding.
2024, 40(8): 1519-1527
doi: 10.11862/CJIC.20240064
Abstract:
To explore the potential application of AlN in optoelectronic devices, based on density functional theory, the photoelectric properties and magnetic properties of intrinsic AlN and rare-earth elements La, Yb doped AlN system were calculated by first principles. The calculation results showed that the intrinsic AlN band gap was 6.060 eV. After the addition of La and Yb, impurity levels were generated at the bottom of the conduction band, which makes the excitation energy required for electrons to be brought from valence to the conduction band lower, which is conducive to the optical transition and improves the optical properties of AlN. Spin-up and spin-down valence bands split after Yb doping, indicating that Yb doping produces magnetism. When La and Yb substitution were doped with AlN, the edge of the absorption band moved to the left in the direction of low energy, and the redshift phenomenon occurred. After doping La and Yb, the static dielectric constant of the AlN system increased from 4.63 to 5.14 and 280.44, respectively, indicating that doping enhances the high voltage resistance of the system. The static refractive index increased from 2.12 to 2.26 and 17.06 respectively, which improves the optical properties of AlN.
To explore the potential application of AlN in optoelectronic devices, based on density functional theory, the photoelectric properties and magnetic properties of intrinsic AlN and rare-earth elements La, Yb doped AlN system were calculated by first principles. The calculation results showed that the intrinsic AlN band gap was 6.060 eV. After the addition of La and Yb, impurity levels were generated at the bottom of the conduction band, which makes the excitation energy required for electrons to be brought from valence to the conduction band lower, which is conducive to the optical transition and improves the optical properties of AlN. Spin-up and spin-down valence bands split after Yb doping, indicating that Yb doping produces magnetism. When La and Yb substitution were doped with AlN, the edge of the absorption band moved to the left in the direction of low energy, and the redshift phenomenon occurred. After doping La and Yb, the static dielectric constant of the AlN system increased from 4.63 to 5.14 and 280.44, respectively, indicating that doping enhances the high voltage resistance of the system. The static refractive index increased from 2.12 to 2.26 and 17.06 respectively, which improves the optical properties of AlN.
2024, 40(8): 1528-1536
doi: 10.11862/CJIC.20240050
Abstract:
The two-dimensional covalent organic framework (COF) membrane material TpOMe-BMTH was prepared on the anodic aluminum oxide (AAO) substrate with 2, 5-di-(2-methoxy-methoxy-ethoxy)-phenylmethylhydrazide (BMTH) and 2, 4, 6-trimethoxy-1, 3, 5-benzenetricarbaldehyde (TpOMe) condensation based on interfacial polymerization. The separation properties of the obtained membrane material for lithium and magnesium ions were investigated. Results showed that the TpOMe-BMTH/AAO membranes possessed high crystallization, good stability, and excellent metal ion selectivity, with a separation factor of up to 258 for Li+/Mg2+ in a binary salt system consisting of LiCl (0.1 mol·L-1) and MgCl2 (0.1 mol·L-1). The plane wave pseudopotential method calculation based on the density functional theory showed that the binding energy of the oxygen-rich oligoether chains in the material pore for Li+ and Mg2+ was -282.69 or -13.46 kJ·mol-1. This result means that the obtained membrane has stronger lithium-philic properties and promotes Li+ adsorption diffusion along the one-dimensional pore of the COF membrane, finally enabling the efficient separation of lithium and magnesium ions.
The two-dimensional covalent organic framework (COF) membrane material TpOMe-BMTH was prepared on the anodic aluminum oxide (AAO) substrate with 2, 5-di-(2-methoxy-methoxy-ethoxy)-phenylmethylhydrazide (BMTH) and 2, 4, 6-trimethoxy-1, 3, 5-benzenetricarbaldehyde (TpOMe) condensation based on interfacial polymerization. The separation properties of the obtained membrane material for lithium and magnesium ions were investigated. Results showed that the TpOMe-BMTH/AAO membranes possessed high crystallization, good stability, and excellent metal ion selectivity, with a separation factor of up to 258 for Li+/Mg2+ in a binary salt system consisting of LiCl (0.1 mol·L-1) and MgCl2 (0.1 mol·L-1). The plane wave pseudopotential method calculation based on the density functional theory showed that the binding energy of the oxygen-rich oligoether chains in the material pore for Li+ and Mg2+ was -282.69 or -13.46 kJ·mol-1. This result means that the obtained membrane has stronger lithium-philic properties and promotes Li+ adsorption diffusion along the one-dimensional pore of the COF membrane, finally enabling the efficient separation of lithium and magnesium ions.
2024, 40(8): 1537-1548
doi: 10.11862/CJIC.20240030
Abstract:
This study displayed a preparation method of efficient and environmentally friendly adsorbent for the removal of Cd(Ⅱ) from water. By directly mixing the modifier Mg(NO3)2 with the precursor resin derived from enzymatic hydrolysis lignin liquefied product resin (LP resin), followed by microwave-foaming and carbonization, a magnesium-modified carbon foam (Mg/CF) was successfully fabricated. The surface functional groups and phase composition of Mg/CF composite adsorbent material were analyzed using an infrared spectrum, X-ray polycrystalline diffractometer, X-ray photoelectron spectroscopy, and other characterization methods. The results revealed that the loaded MgO was evenly distributed on the cell wall of carbon foam in the form of nanoparticles after carbonization. The presence of MgO had a negligible effect on the specific surface area of carbon foam but increased the micropore volume instead. Furthermore, to evaluate the Cd(Ⅱ) removal ability of Mg/CF composite in water, batch adsorption experiments were carried out. The findings indicated that this adsorbent exhibited excellent removal ability for Cd(Ⅱ) in water, with a theoretical maximum adsorption capacity of 308.51 mg·g-1, which was approximately 2.0 times as neat as MgO adsorbent. Further, the equilibrium time (12 h) of this adsorbent was significantly shorter than that of MgO (24 h). Meanwhile, the thermodynamic analysis showed that the Cd(Ⅱ) removal was a spontaneous, endothermic, and entropy-increasing process. The removal behavior of Mg/CF for Cd(Ⅱ) satisfied the pseudo-second-order kinetic equation and Langmuir adsorption isotherm model. It was proposed that the Cd(Ⅱ) removal by Mg/CF composite adsorbent could be mainly attributed to ion exchange and chemical precipitation, accompanied by physisorption.
This study displayed a preparation method of efficient and environmentally friendly adsorbent for the removal of Cd(Ⅱ) from water. By directly mixing the modifier Mg(NO3)2 with the precursor resin derived from enzymatic hydrolysis lignin liquefied product resin (LP resin), followed by microwave-foaming and carbonization, a magnesium-modified carbon foam (Mg/CF) was successfully fabricated. The surface functional groups and phase composition of Mg/CF composite adsorbent material were analyzed using an infrared spectrum, X-ray polycrystalline diffractometer, X-ray photoelectron spectroscopy, and other characterization methods. The results revealed that the loaded MgO was evenly distributed on the cell wall of carbon foam in the form of nanoparticles after carbonization. The presence of MgO had a negligible effect on the specific surface area of carbon foam but increased the micropore volume instead. Furthermore, to evaluate the Cd(Ⅱ) removal ability of Mg/CF composite in water, batch adsorption experiments were carried out. The findings indicated that this adsorbent exhibited excellent removal ability for Cd(Ⅱ) in water, with a theoretical maximum adsorption capacity of 308.51 mg·g-1, which was approximately 2.0 times as neat as MgO adsorbent. Further, the equilibrium time (12 h) of this adsorbent was significantly shorter than that of MgO (24 h). Meanwhile, the thermodynamic analysis showed that the Cd(Ⅱ) removal was a spontaneous, endothermic, and entropy-increasing process. The removal behavior of Mg/CF for Cd(Ⅱ) satisfied the pseudo-second-order kinetic equation and Langmuir adsorption isotherm model. It was proposed that the Cd(Ⅱ) removal by Mg/CF composite adsorbent could be mainly attributed to ion exchange and chemical precipitation, accompanied by physisorption.
2024, 40(8): 1549-1562
doi: 10.11862/CJIC.20240022
Abstract:
Combined with the element doping and morphology controlling strategies, the LiAl0.08Mn1.92O4 cathode material was synthesized by solid-state combustion method and dealt with at different calcination temperatures (600, 650, 700, and 750 ℃). The experimental results showed that the phase structure of LiMn2O4 was not changed by Al doping and the change of calcination temperature. With the increase in temperature, the crystallinity of the sample increased and the particle size enlarged. The calcination temperature of 650 ℃ was the key temperature for the formation of truncated octahedral single crystal particle morphology, and 750 ℃ was the abrupt temperature of the particles that suddenly became larger. The LiAl0.08Mn1.92O4 material with an optimized calcination temperature of 650 ℃ formed a relatively complete truncated octahedral single crystal morphology particle containing (111), (110), and (100) crystal planes, and showed excellent electrochemical and kinetic performance. The initial discharge capacity was 112.0 mAh·g-1 at 1C, and the capacity retention rate was 72.9% after 500 cycles. The initial discharge capacities were 107.1 and 100.4 mAh·g-1 at 5C and 10C, and the capacity retention rates were 52.2% and 53.5% after 2 000 cycles, respectively. It had the minimum redox peak potential difference (ΔEp2=0.109 and 0.114 V before and after cycling respectively), the minimum charge transfer resistance (Rct=106.49 and 125.49 Ω before and after cycling respectively), and the large lithium-ion diffusion coefficient (DLi+=1.72×10-16 cm2·s-1). The Al doping and single crystal truncated octahedral particle morphology not only effectively inhibited the Jahn-Teller effect of LiMn2O4 but also relieved the dissolution of Mn, and improved the rate performance and long cycle life of the materials.
Combined with the element doping and morphology controlling strategies, the LiAl0.08Mn1.92O4 cathode material was synthesized by solid-state combustion method and dealt with at different calcination temperatures (600, 650, 700, and 750 ℃). The experimental results showed that the phase structure of LiMn2O4 was not changed by Al doping and the change of calcination temperature. With the increase in temperature, the crystallinity of the sample increased and the particle size enlarged. The calcination temperature of 650 ℃ was the key temperature for the formation of truncated octahedral single crystal particle morphology, and 750 ℃ was the abrupt temperature of the particles that suddenly became larger. The LiAl0.08Mn1.92O4 material with an optimized calcination temperature of 650 ℃ formed a relatively complete truncated octahedral single crystal morphology particle containing (111), (110), and (100) crystal planes, and showed excellent electrochemical and kinetic performance. The initial discharge capacity was 112.0 mAh·g-1 at 1C, and the capacity retention rate was 72.9% after 500 cycles. The initial discharge capacities were 107.1 and 100.4 mAh·g-1 at 5C and 10C, and the capacity retention rates were 52.2% and 53.5% after 2 000 cycles, respectively. It had the minimum redox peak potential difference (ΔEp2=0.109 and 0.114 V before and after cycling respectively), the minimum charge transfer resistance (Rct=106.49 and 125.49 Ω before and after cycling respectively), and the large lithium-ion diffusion coefficient (DLi+=1.72×10-16 cm2·s-1). The Al doping and single crystal truncated octahedral particle morphology not only effectively inhibited the Jahn-Teller effect of LiMn2O4 but also relieved the dissolution of Mn, and improved the rate performance and long cycle life of the materials.
2024, 40(8): 1563-1576
doi: 10.11862/CJIC.20230374
Abstract:
To explore the regulatory effect of Desmodium styracifolium polysaccharides before and after carboxymethylation (DSPs) on the nucleation, growth and aggregation of calcium oxalate (CaC2O4) crystals, the CaC2O4 crystals regulated by DSPs with different carboxyl (—COOH) contents (mass fractions) were characterized by FTIR, powder X-ray diffraction, scanning electron microscope, ζ potential and thermogravimetric analysis (TGA). The protective effect of DSPs on human renal proximal tubular epithelial cells (HK-2 cells) was evaluated by examining adhesion molecule expression and nano-COM (nano calcium oxalate monohydrate) cell adhesion. The results show that DSPs can inhibit the growth of COM crystals, induce the formation of calcium oxalate dihydrate (COD) crystals, increase the absolute value of ζ potential on the surface of CaC2O4 crystals, and inhibit aggregation between crystals. When the —COOH content in the polysaccharide increased from 1.17% to 7.45%, 12.2% and 17.7%, the ability of DSP0, DSP1, DSP2 and DSP3 to regulate the growth of CaC2O4 crystals increased in sequence. TGA shows that polysaccharides are adsorbed in the crystal. In the presence of 0.2 g·L-1 DSPs, the mass fractions of DSP0, DSP1, DSP2 and DSP3 incorporated into the crystals were 1.54%, 2.94%, 7.96% and 8.12%, respectively. Cell experiments show that DSPs can significantly reduce the expression of adhesion molecules CD44 and Annexin A2 on the surface of HK-2 cells, and reduce the amount of nano-COM adhesion on the cell surface. DSPs can inhibit the nucleation, aggregation, and growth of CaC2O4 crystals, and reduce the adhesion of nano-COM on renal epithelial cells, all these are beneficial to inhibit the formation of CaC2O4 kidney stones, among which DSP3 with the highest degree of carboxylation has the best effect.
To explore the regulatory effect of Desmodium styracifolium polysaccharides before and after carboxymethylation (DSPs) on the nucleation, growth and aggregation of calcium oxalate (CaC2O4) crystals, the CaC2O4 crystals regulated by DSPs with different carboxyl (—COOH) contents (mass fractions) were characterized by FTIR, powder X-ray diffraction, scanning electron microscope, ζ potential and thermogravimetric analysis (TGA). The protective effect of DSPs on human renal proximal tubular epithelial cells (HK-2 cells) was evaluated by examining adhesion molecule expression and nano-COM (nano calcium oxalate monohydrate) cell adhesion. The results show that DSPs can inhibit the growth of COM crystals, induce the formation of calcium oxalate dihydrate (COD) crystals, increase the absolute value of ζ potential on the surface of CaC2O4 crystals, and inhibit aggregation between crystals. When the —COOH content in the polysaccharide increased from 1.17% to 7.45%, 12.2% and 17.7%, the ability of DSP0, DSP1, DSP2 and DSP3 to regulate the growth of CaC2O4 crystals increased in sequence. TGA shows that polysaccharides are adsorbed in the crystal. In the presence of 0.2 g·L-1 DSPs, the mass fractions of DSP0, DSP1, DSP2 and DSP3 incorporated into the crystals were 1.54%, 2.94%, 7.96% and 8.12%, respectively. Cell experiments show that DSPs can significantly reduce the expression of adhesion molecules CD44 and Annexin A2 on the surface of HK-2 cells, and reduce the amount of nano-COM adhesion on the cell surface. DSPs can inhibit the nucleation, aggregation, and growth of CaC2O4 crystals, and reduce the adhesion of nano-COM on renal epithelial cells, all these are beneficial to inhibit the formation of CaC2O4 kidney stones, among which DSP3 with the highest degree of carboxylation has the best effect.
2024, 40(8): 1577-1582
doi: 10.11862/CJIC.20230469
Abstract:
Iron oxide particles with a size of 7 nm were prepared by the oxidation co-precipitation method using Fe2+ as an iron source, 0.4% H2O2 as an oxidant, and NaOH as a precipitator. This experiment further simulated tumor starvation therapy in vitor: in 5 mL (10 μg·mL-1) of glucose oxidase and 15 mL (5 mg·mL-1) of glucose solution system, to explore the optimal conditions for the catalytic performance of catalase (CAT)-like and peroxidase (POD)-like of nano ferrous oxide. The results showed that under 1 mg·mL-1, at pH=5.0, the CAT-like activity of nano Fe3O4 can promote an increase in the reaction rate and limit of glucose oxidation reaction; at pH=5.0, the POD-like activity of nano iron oxide was better. It can catalyze hydrogen peroxide to produce reactive oxygen species with high efficiency.
Iron oxide particles with a size of 7 nm were prepared by the oxidation co-precipitation method using Fe2+ as an iron source, 0.4% H2O2 as an oxidant, and NaOH as a precipitator. This experiment further simulated tumor starvation therapy in vitor: in 5 mL (10 μg·mL-1) of glucose oxidase and 15 mL (5 mg·mL-1) of glucose solution system, to explore the optimal conditions for the catalytic performance of catalase (CAT)-like and peroxidase (POD)-like of nano ferrous oxide. The results showed that under 1 mg·mL-1, at pH=5.0, the CAT-like activity of nano Fe3O4 can promote an increase in the reaction rate and limit of glucose oxidation reaction; at pH=5.0, the POD-like activity of nano iron oxide was better. It can catalyze hydrogen peroxide to produce reactive oxygen species with high efficiency.
2024, 40(8): 1583-1591
doi: 10.11862/CJIC.20240231
Abstract:
A mononuclear CoⅡ complex, [Co(H2dapsc)(H2O)Cl]Cl·2H2O (1), with a pentagonal bipyramidal configuration was obtained by reflux reaction of CoCl2·6H2O and 2, 6-diacetylpyridine-bis(semicarbazone) (H2dapsc) in a mixed solvent of water and ethanol. The neutral ligand H2dapsc molecule provides five coordination atoms to form the equatorial plane of 1, while a water molecule and a Cl- ion occupy their axial positions. At the same time, the solid structure contains a valence counteranion Cl- ion and two lattice water molecules. The study of DC magnetic susceptibility indicates that complex 1 has strong magnetic anisotropy. The AC magnetic properties show the existence of slow magnetic relaxation behavior, which is dominated by both direct and Raman processes. The energy barrier for magnetization reversal was 55.55 K. Based on theoretical calculations, it can be concluded that the main reason for the slow magnetic relaxation behavior is the rhombic anisotropy of the pentagonal bipyramidal structure. The calculated D and E values were 45.68 and-0.32 cm-1.
A mononuclear CoⅡ complex, [Co(H2dapsc)(H2O)Cl]Cl·2H2O (1), with a pentagonal bipyramidal configuration was obtained by reflux reaction of CoCl2·6H2O and 2, 6-diacetylpyridine-bis(semicarbazone) (H2dapsc) in a mixed solvent of water and ethanol. The neutral ligand H2dapsc molecule provides five coordination atoms to form the equatorial plane of 1, while a water molecule and a Cl- ion occupy their axial positions. At the same time, the solid structure contains a valence counteranion Cl- ion and two lattice water molecules. The study of DC magnetic susceptibility indicates that complex 1 has strong magnetic anisotropy. The AC magnetic properties show the existence of slow magnetic relaxation behavior, which is dominated by both direct and Raman processes. The energy barrier for magnetization reversal was 55.55 K. Based on theoretical calculations, it can be concluded that the main reason for the slow magnetic relaxation behavior is the rhombic anisotropy of the pentagonal bipyramidal structure. The calculated D and E values were 45.68 and-0.32 cm-1.
2024, 40(8): 1592-1602
doi: 10.11862/CJIC.20240152
Abstract:
The glycol solvent -thermal method prepared a serial of NiAlNd catalysts based on layered double hydrox-ides (LDHs) precursor. The introduction of Nd greatly promoted the catalytic activity for CO2 methanation at low temperatures. The CO2 conversion on the NiAlNd - 0.4 catalyst reached 83.9% under the reaction condition: T= 210 ℃, WHSV (weight hourly space velocity)=24 000 mL·g-1·h-1, p=100 kPa. The substitution of Nd3+ for Al3+ hin-dered the formation of LDHs structure in the precursor but decreased the particle size of the calcined catalyst. The interaction between NiO and Al2O3 was weakened with the introduction of Nd, resulting in better NiO component reducibility and high intrinsic activity of the Ni site. Moreover, the presence of Nd increased the number of surface basic sites of the catalyst, thus increasing the adsorption of CO2. With the increase in Nd, the surface area of metallic Ni in the reduced catalyst takes on a volcano-shape variation trend. The catalytic activities of NiAlNd catalysts are affected by the number and intrinsic activity of Ni sites simultaneously.
The glycol solvent -thermal method prepared a serial of NiAlNd catalysts based on layered double hydrox-ides (LDHs) precursor. The introduction of Nd greatly promoted the catalytic activity for CO2 methanation at low temperatures. The CO2 conversion on the NiAlNd - 0.4 catalyst reached 83.9% under the reaction condition: T= 210 ℃, WHSV (weight hourly space velocity)=24 000 mL·g-1·h-1, p=100 kPa. The substitution of Nd3+ for Al3+ hin-dered the formation of LDHs structure in the precursor but decreased the particle size of the calcined catalyst. The interaction between NiO and Al2O3 was weakened with the introduction of Nd, resulting in better NiO component reducibility and high intrinsic activity of the Ni site. Moreover, the presence of Nd increased the number of surface basic sites of the catalyst, thus increasing the adsorption of CO2. With the increase in Nd, the surface area of metallic Ni in the reduced catalyst takes on a volcano-shape variation trend. The catalytic activities of NiAlNd catalysts are affected by the number and intrinsic activity of Ni sites simultaneously.
2024, 40(8): 1603-1614
doi: 10.11862/CJIC.20240150
Abstract:
A novel extremely effective fluorescent zinc organic framework probe [Zn6(L)3(2, 2'-bpy)4]·2H2O}n (Zn - MOF) for Cu2+ was prepared by a hydro - solvothermal method, where H4L=1, 4 - bis(3, 5 - dicarboxyphenoxy) benzene and 2, 2' -bpy=2, 2'-bipyridine. Its synthesis, structure, thermal stability, and fluorescence sensing properties are described in this paper. Zn -MOF is capable of identifying Cu2+ and shows good stability according to the fluorescence quenching method. The fluorescence intensity of the Zn-MOF has demonstrated an essential linear connection with the Cu2+ concentration in a concentration range of 0- 1.2 µmol·L-1, with a low limit of detection (LOD) of 67.1 nmol·L-1. More crucially, the obtained results indicating that Zn-MOF selectively recognizes Cu2+ through weak interactions are corroborated by a systematic analysis of X - ray photoelectron spectroscopy, inductively coupled plasma- mass spectrometry, powder X- ray diffraction, and infrared spectra. Furthermore, this Zn-MOF demonstrates strong regeneration capability in five consecutive cycles.
A novel extremely effective fluorescent zinc organic framework probe [Zn6(L)3(2, 2'-bpy)4]·2H2O}n (Zn - MOF) for Cu2+ was prepared by a hydro - solvothermal method, where H4L=1, 4 - bis(3, 5 - dicarboxyphenoxy) benzene and 2, 2' -bpy=2, 2'-bipyridine. Its synthesis, structure, thermal stability, and fluorescence sensing properties are described in this paper. Zn -MOF is capable of identifying Cu2+ and shows good stability according to the fluorescence quenching method. The fluorescence intensity of the Zn-MOF has demonstrated an essential linear connection with the Cu2+ concentration in a concentration range of 0- 1.2 µmol·L-1, with a low limit of detection (LOD) of 67.1 nmol·L-1. More crucially, the obtained results indicating that Zn-MOF selectively recognizes Cu2+ through weak interactions are corroborated by a systematic analysis of X - ray photoelectron spectroscopy, inductively coupled plasma- mass spectrometry, powder X- ray diffraction, and infrared spectra. Furthermore, this Zn-MOF demonstrates strong regeneration capability in five consecutive cycles.
A Bi-CP-based solid-state thin-film sensor: Preparation and luminescence sensing for bioamine vapors
2024, 40(8): 1615-1621
doi: 10.11862/CJIC.20240134
Abstract:
A 1D coordination polymer (CP), (TBA) [Bi(bp4do)Br4] (1), was synthesized by the assembly of 4, 4' - bipyridine -N, N'-dioxide (bp4do) and Bi3+ (TBA+=tetrabutylammonium). 1 exhibits a red luminescence with a quantum yield of up to 69%. A solid-state thin-film sensor (1/PVP) with extremely high luminescence stability was prepared by combining 1 with polyvinyl pyrrolidone (PVP). 1/PVP has a wide - range sensing capability for 11 NH3/amine vapors with rapid response. During the sensing process, its luminescence color changed from red to blue, which was easy for naked -eye observation. The sensing mechanism is NH3/amine-induced collapse of the framework of 1. Furthermore, 1/PVP has been successfully applied to monitoring food freshness such as meat/aquatic products.
A 1D coordination polymer (CP), (TBA) [Bi(bp4do)Br4] (1), was synthesized by the assembly of 4, 4' - bipyridine -N, N'-dioxide (bp4do) and Bi3+ (TBA+=tetrabutylammonium). 1 exhibits a red luminescence with a quantum yield of up to 69%. A solid-state thin-film sensor (1/PVP) with extremely high luminescence stability was prepared by combining 1 with polyvinyl pyrrolidone (PVP). 1/PVP has a wide - range sensing capability for 11 NH3/amine vapors with rapid response. During the sensing process, its luminescence color changed from red to blue, which was easy for naked -eye observation. The sensing mechanism is NH3/amine-induced collapse of the framework of 1. Furthermore, 1/PVP has been successfully applied to monitoring food freshness such as meat/aquatic products.
2024, 40(8): 1622-1632
doi: 10.11862/CJIC.20240107
Abstract:
A photothermal agent (ECEI) with high photothermal conversion efficiency (85.78%) was synthesized based on coumarin fluorescent groups. In addition, the experimental results of hot and cold cycling show that ECEI has good photostability. Despite damage to the mitochondrial membrane potential, ECEI can effectively target mitochondria and induce cancer cell death under laser irradiation. This allows ECEI to maximize mitochondrial damage and thus inhibit tumor cell reproduction. Notable, after irradiating mouse tumors once, the mouse tumors gradually disappeared within 10 d. This indicates that ECEI has an excellent tumor inhibition effect.
A photothermal agent (ECEI) with high photothermal conversion efficiency (85.78%) was synthesized based on coumarin fluorescent groups. In addition, the experimental results of hot and cold cycling show that ECEI has good photostability. Despite damage to the mitochondrial membrane potential, ECEI can effectively target mitochondria and induce cancer cell death under laser irradiation. This allows ECEI to maximize mitochondrial damage and thus inhibit tumor cell reproduction. Notable, after irradiating mouse tumors once, the mouse tumors gradually disappeared within 10 d. This indicates that ECEI has an excellent tumor inhibition effect.
