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2021 Volume 37 Issue 2
2021, 37(2): 193-205
doi: 10.11862/CJIC.2021.044
Abstract:
For its magnetic bistability and slow relaxation process, single-ion magnets (SIMs) have unique potential applications in high-density information storage, quantum computation and molecular spintronics. 3d transitionmetal-based single ion magnets (3d-SIMs) have attracted intensive interest because of their simple structure, easily exploring the magneto-structural relationship. Up to now, most of the 3d-SIMs reported in the literature usually have low coordination numbers, while knowledge on the high-coordinated (sevenand eight-coordinated) 3d-SIMs is still quite limited, especially for its efficient design and controllable manipulation. This project investigates the singleion magnetic anisotropy from three aspects, including basic properties, experimental characterization and theoretical calculation. Based on the research results in recent years, we summarize the coordination environment, magnetic anisotropy and slow magnetic relaxation behavior of the high-coordinated 3d-SIMs, and analyze the influence of the coordination environment, including coordination geometry and coordinated atoms, on the magnetic anisotropy of highcoordinated 3d-SIMs. This work will provide new routes in designing new high-coordinated 3d-SIMs with excellent properties.
For its magnetic bistability and slow relaxation process, single-ion magnets (SIMs) have unique potential applications in high-density information storage, quantum computation and molecular spintronics. 3d transitionmetal-based single ion magnets (3d-SIMs) have attracted intensive interest because of their simple structure, easily exploring the magneto-structural relationship. Up to now, most of the 3d-SIMs reported in the literature usually have low coordination numbers, while knowledge on the high-coordinated (sevenand eight-coordinated) 3d-SIMs is still quite limited, especially for its efficient design and controllable manipulation. This project investigates the singleion magnetic anisotropy from three aspects, including basic properties, experimental characterization and theoretical calculation. Based on the research results in recent years, we summarize the coordination environment, magnetic anisotropy and slow magnetic relaxation behavior of the high-coordinated 3d-SIMs, and analyze the influence of the coordination environment, including coordination geometry and coordinated atoms, on the magnetic anisotropy of highcoordinated 3d-SIMs. This work will provide new routes in designing new high-coordinated 3d-SIMs with excellent properties.
2021, 37(2): 206-212
doi: 10.11862/CJIC.2021.042
Abstract:
In order to develop supercapacitors with higher energy density, a three-dimensional cobalt-based metalorganic framework (MOF) compound ([KCo7(OH)3(ip)6(H2O)4]·12H2O, Co ip; ip=isophthalate) was synthesized by simple solvothermal reaction. Its electrochemical performances as a supercapacitor electrode material were investigated. The Co-ip electrode exhibited high specific capacitance, good cycle stability, and superior rate performance. In 1 mol·L-1 KOH solution, the maximum specific capacitance was 1 660 F·g-1 at a current density of 1 A·g-1. At a current density of 2 A·g-1, the retention of specific capacitance was 82.7% after 3 000 cycles. The superior supercapacitive performance is attributed to the three-dimensional porous structure of Co-ip and nano-sized particles.
In order to develop supercapacitors with higher energy density, a three-dimensional cobalt-based metalorganic framework (MOF) compound ([KCo7(OH)3(ip)6(H2O)4]·12H2O, Co ip; ip=isophthalate) was synthesized by simple solvothermal reaction. Its electrochemical performances as a supercapacitor electrode material were investigated. The Co-ip electrode exhibited high specific capacitance, good cycle stability, and superior rate performance. In 1 mol·L-1 KOH solution, the maximum specific capacitance was 1 660 F·g-1 at a current density of 1 A·g-1. At a current density of 2 A·g-1, the retention of specific capacitance was 82.7% after 3 000 cycles. The superior supercapacitive performance is attributed to the three-dimensional porous structure of Co-ip and nano-sized particles.
2021, 37(2): 213-220
doi: 10.11862/CJIC.2021.041
Abstract:
A series of 1-(1-ethyl-1H-indol-3-yl)-4, 4, 4-trifluorobutane-1, 3-dione (EIFD) dysprosium complexes, namely[Dy(EIFD)3(EM)]·CH2Cl2 (1), [Dy(EIFD)3(EDM)]·CH2Cl2 (2) and[Dy(EIFD)3(TEG)] (3) (EM=CH3OCH2CH2OH, EDM=CH3OCH2CH2OCH3, TEG=HOCH2CH2OCH2CH2OCH2CH2OH), have been isolated by reactions of EIFD, DyCl3·6H2O and corresponding oxygen-containing auxiliary ligands, respectively. X-ray crystallographic analysis reveals that complexes 1~3 are all eight coordinated mononuclear structures. The coordination geometry for Dy(Ⅲ) ion in complexes 1 and 3 are suggested closer to the biaugmented trigonal prismatic (8-BTP, C2v), in contrast, it is closer to the triangular dodecahedron (8-TDH, D2d) for complex 2. Magnetic studies indicate that all complexes 1~3 exhibit slowed magnetic relaxation with anisotropy energy barriers of 95.1 K for 1, 40.5 K for 2 as well as 53.8 and 13.4 K for 3, respectively. Complexes 1 and 3 showed butterfly-loop. In view of the β-diketone ligand of EIFD, Dy (Ⅲ) complexes with oxygen containing auxiliary ligands displayed higher energy barriers than those of complexes with nitrogen containing auxiliary ligands. The Dy-O bond length and electronic effect of oxygen containing auxiliary ligands in the complexes have been investigated in terms of their anisotropy energy barriers. CCDC: 1893554, 1; 1893555, 2; 1893556, 3.
A series of 1-(1-ethyl-1H-indol-3-yl)-4, 4, 4-trifluorobutane-1, 3-dione (EIFD) dysprosium complexes, namely[Dy(EIFD)3(EM)]·CH2Cl2 (1), [Dy(EIFD)3(EDM)]·CH2Cl2 (2) and[Dy(EIFD)3(TEG)] (3) (EM=CH3OCH2CH2OH, EDM=CH3OCH2CH2OCH3, TEG=HOCH2CH2OCH2CH2OCH2CH2OH), have been isolated by reactions of EIFD, DyCl3·6H2O and corresponding oxygen-containing auxiliary ligands, respectively. X-ray crystallographic analysis reveals that complexes 1~3 are all eight coordinated mononuclear structures. The coordination geometry for Dy(Ⅲ) ion in complexes 1 and 3 are suggested closer to the biaugmented trigonal prismatic (8-BTP, C2v), in contrast, it is closer to the triangular dodecahedron (8-TDH, D2d) for complex 2. Magnetic studies indicate that all complexes 1~3 exhibit slowed magnetic relaxation with anisotropy energy barriers of 95.1 K for 1, 40.5 K for 2 as well as 53.8 and 13.4 K for 3, respectively. Complexes 1 and 3 showed butterfly-loop. In view of the β-diketone ligand of EIFD, Dy (Ⅲ) complexes with oxygen containing auxiliary ligands displayed higher energy barriers than those of complexes with nitrogen containing auxiliary ligands. The Dy-O bond length and electronic effect of oxygen containing auxiliary ligands in the complexes have been investigated in terms of their anisotropy energy barriers. CCDC: 1893554, 1; 1893555, 2; 1893556, 3.
2021, 37(2): 221-228
doi: 10.11862/CJIC.2021.036
Abstract:
A new long-chain alkoxy imine derivative R was designed and synthesized. The recognition property of the receptor R for 10 kinds of anions was studied by UV-Vis analysis and naked-eye detection. The results showed that the receptor R had significant recognition ability for F-, Ac- and CN- through UV-Vis analysis, which found single colorimetric recognition of CN- by naked-eye recognition in H2O/DMSO (1:1, V/V) solution. The LOD (limit of lowest detection) of receptor R for CN- was 7.02 μmol·L-1, and naked recognition paper of receptor R was prepared. The Job's plot indicated that the formation of complex between receptor R and CN- was in 1:2 stoichiometric ratio. The recognition mechanism of receptor R was illustrated through UV titration, NMR titration, MS and theoretical calculation. The "reaction" and "hydrogen-bond" double response recognition phenomena and deprotonation were found in the CN- and F- titrations, respectively.
A new long-chain alkoxy imine derivative R was designed and synthesized. The recognition property of the receptor R for 10 kinds of anions was studied by UV-Vis analysis and naked-eye detection. The results showed that the receptor R had significant recognition ability for F-, Ac- and CN- through UV-Vis analysis, which found single colorimetric recognition of CN- by naked-eye recognition in H2O/DMSO (1:1, V/V) solution. The LOD (limit of lowest detection) of receptor R for CN- was 7.02 μmol·L-1, and naked recognition paper of receptor R was prepared. The Job's plot indicated that the formation of complex between receptor R and CN- was in 1:2 stoichiometric ratio. The recognition mechanism of receptor R was illustrated through UV titration, NMR titration, MS and theoretical calculation. The "reaction" and "hydrogen-bond" double response recognition phenomena and deprotonation were found in the CN- and F- titrations, respectively.
Preparation and Luminescence Performance of Tb3+, Sm3+ Doped YNbO4 Multicolor Luminescence Materials
2021, 37(2): 229-234
doi: 10.11862/CJIC.2021.004
Abstract:
A series of YNbO4:Tb3+, Sm3+ phosphors were synthesized by sol-gel process. Photoluminescence spectra show that NbO43- group can absorb ultraviolet light and transfer energy to Tb3+ and Sm3+, then enhance the luminescence intensity of the phosphor. Under the excitation of 290 nm, characteristic green emission of Tb3+ and orange red emission of Sm3+ were presented in the emission spectrum of YNbO4:Tb3+, Sm3+ phosphors. Therefore, the emitting color can be adjusted by changing the doping concentration of Sm3+.
A series of YNbO4:Tb3+, Sm3+ phosphors were synthesized by sol-gel process. Photoluminescence spectra show that NbO43- group can absorb ultraviolet light and transfer energy to Tb3+ and Sm3+, then enhance the luminescence intensity of the phosphor. Under the excitation of 290 nm, characteristic green emission of Tb3+ and orange red emission of Sm3+ were presented in the emission spectrum of YNbO4:Tb3+, Sm3+ phosphors. Therefore, the emitting color can be adjusted by changing the doping concentration of Sm3+.
2021, 37(2): 235-242
doi: 10.11862/CJIC.2021.035
Abstract:
Complexes[Ag(4-PIM)]ClO4 (1) and[Zn(IPI)]Cl2·H2O (2) were synthesized by the reaction of ligand 2-(4pyridinyl)-imidazole (4-PIM) and 2-(4-(1-imidazolylphenyl))-imidazole (IPI) with AgClO4 and ZnCl2, respectively. Xray crystallography analysis reveals that complexes 1 and 2 have metal-organic macrocyclic structure of M4L4 and M2L2 type, respectively. And there are stronger intermolecular forces, π-π stacking effect and hydrogen-bonding interactions in the crystal structures of complexes. Metal-organic gels were formed by using rigid ligand IPI to react with AgNO3 and Zn(NO3)2 in methanol, ethanol, dimethyl sulfoxide, ethylene glycol, tetrahydrofuran and acetonitrile, respectively. Supramolecular metal-organic gels were also self-assemblied through ligand IPI reacting with AgNO3, AgClO4, AgBF4, AgPF6, AgOSO2CF3, Zn(NO3)2, Zn(BF4)2, Zn(ClO4)2 and Co(NO3)2 in ethanol solvent, respectively. The hydrogen-bonding interactions between solvent molecules and N-H in the imidazole rings of ligand IPI may be the key factor to form gels. Scanning electron microscopy (SEM) images showed that metal-organic supramolecular gels based on silver salts or zinic salts had fluffy cotton-like and loose bread-like structure, respectively. CCDC: 2017307, 1; 2017308, 2.
Complexes[Ag(4-PIM)]ClO4 (1) and[Zn(IPI)]Cl2·H2O (2) were synthesized by the reaction of ligand 2-(4pyridinyl)-imidazole (4-PIM) and 2-(4-(1-imidazolylphenyl))-imidazole (IPI) with AgClO4 and ZnCl2, respectively. Xray crystallography analysis reveals that complexes 1 and 2 have metal-organic macrocyclic structure of M4L4 and M2L2 type, respectively. And there are stronger intermolecular forces, π-π stacking effect and hydrogen-bonding interactions in the crystal structures of complexes. Metal-organic gels were formed by using rigid ligand IPI to react with AgNO3 and Zn(NO3)2 in methanol, ethanol, dimethyl sulfoxide, ethylene glycol, tetrahydrofuran and acetonitrile, respectively. Supramolecular metal-organic gels were also self-assemblied through ligand IPI reacting with AgNO3, AgClO4, AgBF4, AgPF6, AgOSO2CF3, Zn(NO3)2, Zn(BF4)2, Zn(ClO4)2 and Co(NO3)2 in ethanol solvent, respectively. The hydrogen-bonding interactions between solvent molecules and N-H in the imidazole rings of ligand IPI may be the key factor to form gels. Scanning electron microscopy (SEM) images showed that metal-organic supramolecular gels based on silver salts or zinic salts had fluffy cotton-like and loose bread-like structure, respectively. CCDC: 2017307, 1; 2017308, 2.
2021, 37(2): 243-250
doi: 10.11862/CJIC.2021.024
Abstract:
Ordered mesoporous nitrogen doped carbon supported iron oxide was prepared, which effectively reduced the overpotential of oxygen reduction. The physicochemical properties of the as-prepared catalysts were characterized by scanning electron microscopy, transmission electron microscopy, nitrogen adsorption-desorption test, powder X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy. In addition, the activity and selectivity for oxygen reduction reaction was tested by rotating disc electrode under alkaline conditions. The results show that iron was loaded in ordered mesoporous nitrogen doped carbon in the form of Fe2O3 after nitrogen pyrolysis, and its specific surface area reached 755 cm2·g-1. The results of Raman and X-ray photoelectron spectroscopy show that the graphitization degree of the catalyst increased with adding iron precursor. The impedance was decreased and its conductivity was increased. Under alkaline conditions, Fe2O3@NC exhibited a 4-electron oxygen reduction reaction, and its initial potential (-0.01 V vs Ag/AgCl) and half slope potential (-0.13 V vs Ag/AgCl) were comparable to those of commercial 20% Pt/C. In addition, the catalyst had superior methanol resistance and excellent constant voltage stability compared with commercial Pt/C. The discharge power of Fe2O3@NC reached 88 mW·cm-2, which was 1.29 times that of commercial Pt/C.
Ordered mesoporous nitrogen doped carbon supported iron oxide was prepared, which effectively reduced the overpotential of oxygen reduction. The physicochemical properties of the as-prepared catalysts were characterized by scanning electron microscopy, transmission electron microscopy, nitrogen adsorption-desorption test, powder X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy. In addition, the activity and selectivity for oxygen reduction reaction was tested by rotating disc electrode under alkaline conditions. The results show that iron was loaded in ordered mesoporous nitrogen doped carbon in the form of Fe2O3 after nitrogen pyrolysis, and its specific surface area reached 755 cm2·g-1. The results of Raman and X-ray photoelectron spectroscopy show that the graphitization degree of the catalyst increased with adding iron precursor. The impedance was decreased and its conductivity was increased. Under alkaline conditions, Fe2O3@NC exhibited a 4-electron oxygen reduction reaction, and its initial potential (-0.01 V vs Ag/AgCl) and half slope potential (-0.13 V vs Ag/AgCl) were comparable to those of commercial 20% Pt/C. In addition, the catalyst had superior methanol resistance and excellent constant voltage stability compared with commercial Pt/C. The discharge power of Fe2O3@NC reached 88 mW·cm-2, which was 1.29 times that of commercial Pt/C.
2021, 37(2): 251-258
doi: 10.11862/CJIC.2021.023
Abstract:
Three complexes, [Cd(HL)Cl2]2 (1), [Cd(HL)2Br2] (2) and[Cd(HL)I2] (3) (HL=2-(4-chlorophenoxy)-N'-(pyridin-2-ylmethylene)acetohydrazide), were synthesized using a common solution method. The crystal structure and properties were studied by X-ray single crystal diffraction, infrared spectrum, ultraviolet spectrum, fluorescence spectrum and thermogravimetric analysis. The analysis of single crystal diffraction structure shows that complex 1 belongs to monoclinic system, C2/c space group, and is a dimer bridged by chlorine ions. Complex 2 belongs to monoclinic system, P21/c space group. It is a butterfly shaped mononuclear molecule containing two organic ligands. The central Cd2+ ions of complexes 1 and 2 are in a distorted octahedral position. Complex 3 belongs to triclinic system, P1 space group, in which there is only one organic ligand. The coordination polyhedron of Cd2+ ion of complex 3 is distorted trigonal bipyramid. Solid fluorescence analysis showed that both ligand and complexes had strong fluorescence and emitted green light. CCDC: 2011521, 1; 2011522, 2; 2011523, 3.
Three complexes, [Cd(HL)Cl2]2 (1), [Cd(HL)2Br2] (2) and[Cd(HL)I2] (3) (HL=2-(4-chlorophenoxy)-N'-(pyridin-2-ylmethylene)acetohydrazide), were synthesized using a common solution method. The crystal structure and properties were studied by X-ray single crystal diffraction, infrared spectrum, ultraviolet spectrum, fluorescence spectrum and thermogravimetric analysis. The analysis of single crystal diffraction structure shows that complex 1 belongs to monoclinic system, C2/c space group, and is a dimer bridged by chlorine ions. Complex 2 belongs to monoclinic system, P21/c space group. It is a butterfly shaped mononuclear molecule containing two organic ligands. The central Cd2+ ions of complexes 1 and 2 are in a distorted octahedral position. Complex 3 belongs to triclinic system, P1 space group, in which there is only one organic ligand. The coordination polyhedron of Cd2+ ion of complex 3 is distorted trigonal bipyramid. Solid fluorescence analysis showed that both ligand and complexes had strong fluorescence and emitted green light. CCDC: 2011521, 1; 2011522, 2; 2011523, 3.
2021, 37(2): 259-266
doi: 10.11862/CJIC.2021.016
Abstract:
Herein, a representative metal-organic framework (MOF), MIL-101(Cr), with a large specific surface area and good hydrothermal stability, has been chosen as porous support. The introducing of Cu(Ⅱ) precursor and reduction to Cu(Ⅰ) were sequentially occurred in the pores of MIL-101(Cr) via double-solvent method (DSM) in which the CuCl2 was directly used for reduction and vitamin C was employed as a green reductant. The DSM is effective in preparing Cu(Ⅰ) sites on support MIL-101(Cr). By using the DSM, it can ensure that the structure of support material was maintained on account of mild operating conditions and all copper species in MIL-101(Cr) were reduced to Cu (Ⅰ). When CuCl content was 2.85 mmol·g-1, the obtained Cu(Ⅰ)-containing materials exhibited a thiophene adsorption capacity (up to 0.175 mmol·g-1), obviously higher than that of pristine MIL 101(Cr) (0.112 mmol·g-1). This method thus offers a useful, controllable and green approach to form Cu(Ⅰ) sites within MOFs under relatively facile conditions. The resultant adsorbents exhibit obviously enhanced adsorptive desulfurization performance because of the specific interaction between Cu(Ⅰ) and thiophenic sulfur compounds.
Herein, a representative metal-organic framework (MOF), MIL-101(Cr), with a large specific surface area and good hydrothermal stability, has been chosen as porous support. The introducing of Cu(Ⅱ) precursor and reduction to Cu(Ⅰ) were sequentially occurred in the pores of MIL-101(Cr) via double-solvent method (DSM) in which the CuCl2 was directly used for reduction and vitamin C was employed as a green reductant. The DSM is effective in preparing Cu(Ⅰ) sites on support MIL-101(Cr). By using the DSM, it can ensure that the structure of support material was maintained on account of mild operating conditions and all copper species in MIL-101(Cr) were reduced to Cu (Ⅰ). When CuCl content was 2.85 mmol·g-1, the obtained Cu(Ⅰ)-containing materials exhibited a thiophene adsorption capacity (up to 0.175 mmol·g-1), obviously higher than that of pristine MIL 101(Cr) (0.112 mmol·g-1). This method thus offers a useful, controllable and green approach to form Cu(Ⅰ) sites within MOFs under relatively facile conditions. The resultant adsorbents exhibit obviously enhanced adsorptive desulfurization performance because of the specific interaction between Cu(Ⅰ) and thiophenic sulfur compounds.
2021, 37(2): 267-275
doi: 10.11862/CJIC.2021.022
Abstract:
Herein, the room temperature treatment of Co3O4 nanorods via NaBH4 aqueous solution results in situ generation of amorphous CoBx nanosheets on nanorods (CoBx/Co3O4) electrocatalyst with abundant oxygen vacancies. The X-ray diffractometer (XRD), field emission scanning electron microscope (FESEM), transmission electron microscope (TEM), and X-ray photoelectron spectroscope (XPS) were applied to investigate the crystal structures, morphologies, element distribution, and chemical states of the prepared electrocatalysts. The activity, stability, and electrochemical impedance spectroscopy (EIS) were recorded by an electrochemical workstation. The amorphous CoBx and oxygen vacancies were formed on surface of Co3O4 nanorods as active sites after treatment via NaBH4. The CoBx/Co3O4 showed excellent performance for oxygen evolution reaction (OER) with lower overpotential of 298 mV than that of Co3O4 (346 mV) to achieve a current density of 10 mA·cm-2 in 1.0 mol·L-1 KOH.
Herein, the room temperature treatment of Co3O4 nanorods via NaBH4 aqueous solution results in situ generation of amorphous CoBx nanosheets on nanorods (CoBx/Co3O4) electrocatalyst with abundant oxygen vacancies. The X-ray diffractometer (XRD), field emission scanning electron microscope (FESEM), transmission electron microscope (TEM), and X-ray photoelectron spectroscope (XPS) were applied to investigate the crystal structures, morphologies, element distribution, and chemical states of the prepared electrocatalysts. The activity, stability, and electrochemical impedance spectroscopy (EIS) were recorded by an electrochemical workstation. The amorphous CoBx and oxygen vacancies were formed on surface of Co3O4 nanorods as active sites after treatment via NaBH4. The CoBx/Co3O4 showed excellent performance for oxygen evolution reaction (OER) with lower overpotential of 298 mV than that of Co3O4 (346 mV) to achieve a current density of 10 mA·cm-2 in 1.0 mol·L-1 KOH.
2021, 37(2): 276-284
doi: 10.11862/CJIC.2021.046
Abstract:
A single crystal polyhedron LiMn1.94B0.06O4 cathode material was prepared by a solid-state combustion synthesis, their structural and electrochemical properties were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and charge-discharge test. The results show that Bdoping did not change the crystal structure of spinel LiMn2O4, and it could promote the preferential growth of (440) and (400) crystal facets. Inducing the formation of the single crystal polyhedron LiMn1.94B0.06O4 material with the highly exposed (111) facets and a small part of (110) and (100) facets, as well as a particle size of 160~350 nm, which enabled minimal Mn dissolution and provided more lithium ions channels. The LiMn1.94B0.06O4 delivered the initial discharge capacity of 103 mAh·g-1 with a good capacity retention rate of 57.7% after 2 000 cycles at 10C and 25℃. At high current rate of 15C, it showed the initial discharge capacity of 67.1 mAh·g-1, and the capacity retention rates of 46.2% was obtained after 1 500 cycles. Moreover, at 1C and high temperature of 55℃, the initial discharge capacity of 125.2 mAh·g-1 was also maintained, showing good high temperature performance. The B-doping can effectively improve the high rate performance and cycle life of spinel LiMn2O4, stabilize the crystal structure, inhibit the Jahn-Teller effect and relieve the Mn dissolution.
A single crystal polyhedron LiMn1.94B0.06O4 cathode material was prepared by a solid-state combustion synthesis, their structural and electrochemical properties were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and charge-discharge test. The results show that Bdoping did not change the crystal structure of spinel LiMn2O4, and it could promote the preferential growth of (440) and (400) crystal facets. Inducing the formation of the single crystal polyhedron LiMn1.94B0.06O4 material with the highly exposed (111) facets and a small part of (110) and (100) facets, as well as a particle size of 160~350 nm, which enabled minimal Mn dissolution and provided more lithium ions channels. The LiMn1.94B0.06O4 delivered the initial discharge capacity of 103 mAh·g-1 with a good capacity retention rate of 57.7% after 2 000 cycles at 10C and 25℃. At high current rate of 15C, it showed the initial discharge capacity of 67.1 mAh·g-1, and the capacity retention rates of 46.2% was obtained after 1 500 cycles. Moreover, at 1C and high temperature of 55℃, the initial discharge capacity of 125.2 mAh·g-1 was also maintained, showing good high temperature performance. The B-doping can effectively improve the high rate performance and cycle life of spinel LiMn2O4, stabilize the crystal structure, inhibit the Jahn-Teller effect and relieve the Mn dissolution.
2021, 37(2): 285-294
doi: 10.11862/CJIC.2021.043
Abstract:
Herein, pyrochlore structure Y2-xMgxRu2O7-δ (YMRO-x, x=0.05, 0.1, 0.15) catalysts were prepared by solgel method. The X-ray photoelectron spectroscopy was employed to analyze the surface chemical composition and valence state of as-synthesized YMRO. The results showed that oxygen defects were increased when Mg2+ partially substituted Y3+ of A site in pyrochlore (A2B2O7-δ). Especially, YMRO-0.1 catalyst possessed the most extraordinary performance in oxygen evolution reaction (OER). Reaching current density of 10 mA·cm-2 only required 265 mV overpotential, outperformed the RuO2 (358 mV), Y2Ru2O7-δ (294 mV), YMRO-0.05 (282 mV) and YMRO-0.15 (281 mV). The Tafel slope of YMRO-0.1 was 45 mV·dec-1, much smaller than that of RuO2 (88 mV·dec-1), YRO (64 mV·dec-1), YMRO-0.05 (51 mV·dec-1) and YMRO-0.15 (52 mV·dec-1), having the fastest kinetic process. Turning to stability test of YMRO-0.1, the potential moved little in 12 h, compared with Y2Ru2O7-δ which shifted up 30 mV under acidic environment. Moreover, first principle calculation indicated that the substitution atom MgY formed a complex with oxygen vacancies, favored the formation of oxygen vacancies, narrowed the band gap, and lowered the charge-transfer-energy. In addition, the excellent OER reactivity can be partly attributed to the Ru5+ ions. Due to the introduction of Mg, the Ru4+ ions at central active site was oxidized to Ru5+ ions, donating electron to surface and accelerating the process of oxygen evolution reaction. As a result, the active sites also minimized Gibbs free energy of oxygen radical desorption, which promoted the OER. Based on the results, YMRO should be a promising OER catalytic material which can stably work in acid environment.
Herein, pyrochlore structure Y2-xMgxRu2O7-δ (YMRO-x, x=0.05, 0.1, 0.15) catalysts were prepared by solgel method. The X-ray photoelectron spectroscopy was employed to analyze the surface chemical composition and valence state of as-synthesized YMRO. The results showed that oxygen defects were increased when Mg2+ partially substituted Y3+ of A site in pyrochlore (A2B2O7-δ). Especially, YMRO-0.1 catalyst possessed the most extraordinary performance in oxygen evolution reaction (OER). Reaching current density of 10 mA·cm-2 only required 265 mV overpotential, outperformed the RuO2 (358 mV), Y2Ru2O7-δ (294 mV), YMRO-0.05 (282 mV) and YMRO-0.15 (281 mV). The Tafel slope of YMRO-0.1 was 45 mV·dec-1, much smaller than that of RuO2 (88 mV·dec-1), YRO (64 mV·dec-1), YMRO-0.05 (51 mV·dec-1) and YMRO-0.15 (52 mV·dec-1), having the fastest kinetic process. Turning to stability test of YMRO-0.1, the potential moved little in 12 h, compared with Y2Ru2O7-δ which shifted up 30 mV under acidic environment. Moreover, first principle calculation indicated that the substitution atom MgY formed a complex with oxygen vacancies, favored the formation of oxygen vacancies, narrowed the band gap, and lowered the charge-transfer-energy. In addition, the excellent OER reactivity can be partly attributed to the Ru5+ ions. Due to the introduction of Mg, the Ru4+ ions at central active site was oxidized to Ru5+ ions, donating electron to surface and accelerating the process of oxygen evolution reaction. As a result, the active sites also minimized Gibbs free energy of oxygen radical desorption, which promoted the OER. Based on the results, YMRO should be a promising OER catalytic material which can stably work in acid environment.
2021, 37(2): 295-304
doi: 10.11862/CJIC.2021.031
Abstract:
The NiTe/Ni electrode was obtained in the mixed solvent of ethanolamine and KOH. Subsequently, the Co9S8/NiTe/Ni composite electrode with a sandwich-like structure was fabricated after the hydrothermal treatment in the aqueous solution of Co(NO3)2 and thiourea. The electrode not only exhibited an ultra-high specific capacity of 1 890 F·g-1 at a current density of 2 A·g-1, but also exhibited excellent cyclic stabilities at high current densities.
The NiTe/Ni electrode was obtained in the mixed solvent of ethanolamine and KOH. Subsequently, the Co9S8/NiTe/Ni composite electrode with a sandwich-like structure was fabricated after the hydrothermal treatment in the aqueous solution of Co(NO3)2 and thiourea. The electrode not only exhibited an ultra-high specific capacity of 1 890 F·g-1 at a current density of 2 A·g-1, but also exhibited excellent cyclic stabilities at high current densities.
2021, 37(2): 305-315
doi: 10.11862/CJIC.2021.034
Abstract:
The organic - inorganic hybrid crystalline material (C7H11N2)4[MoOBr4(H2O)]2Br2 (1) was synthesized by solvent evaporation method in the mixed solution of methanol, ethanol, water and hydrobromic acid using 4-dimethylaminopyridine and ammonium molybdate as raw materials. The crystal structure, thermal and electrical properties were characterized by infrared spectroscopy, single crystal X-ray diffraction, powder X-ray diffraction, thermogravimetric analysis and dielectric measurements and differential thermal analysis. Single crystal X-ray diffraction displayed one dimensional chain and multi dimensional hydrogen bonding network structure through anions and cations forming π-π stacking in space. When the temperature changed, the structural cavity deformation with molybdenum complex ion[MoOBr4(H2O)]- as the vertex caused the hydrogen-bonding dihedral angles of tetramer[MoOBr4(H2O)]2Br2 to occur obvious folding oscillation, which results in the distinct thermal energy with structural phase transition and reversible dielectric anomaly observed at around 238 K. CCDC: 2024338, 1-LT; 2024339, 1-RT.
The organic - inorganic hybrid crystalline material (C7H11N2)4[MoOBr4(H2O)]2Br2 (1) was synthesized by solvent evaporation method in the mixed solution of methanol, ethanol, water and hydrobromic acid using 4-dimethylaminopyridine and ammonium molybdate as raw materials. The crystal structure, thermal and electrical properties were characterized by infrared spectroscopy, single crystal X-ray diffraction, powder X-ray diffraction, thermogravimetric analysis and dielectric measurements and differential thermal analysis. Single crystal X-ray diffraction displayed one dimensional chain and multi dimensional hydrogen bonding network structure through anions and cations forming π-π stacking in space. When the temperature changed, the structural cavity deformation with molybdenum complex ion[MoOBr4(H2O)]- as the vertex caused the hydrogen-bonding dihedral angles of tetramer[MoOBr4(H2O)]2Br2 to occur obvious folding oscillation, which results in the distinct thermal energy with structural phase transition and reversible dielectric anomaly observed at around 238 K. CCDC: 2024338, 1-LT; 2024339, 1-RT.
2021, 37(2): 316-326
doi: 10.11862/CJIC.2021.053
Abstract:
Herein, a direct Z-scheme heterojunction CeO2@NiAl-LDHs (LDHs=layered double hydroxides) with core-shell structure was constructed. It shows high oxidative degradation of rhodamine B (36.91 mg·g-1·h-1) and hydrogen production by photoreduction (14.08 mmol·g-1·h-1). Density functional theory (DFT) calculation shows that there was a built-in electric field in the heterojunction, which promotes the electron transfer from LDHs to CeO2. Surface photovoltage spectroscopy (SPV) and transient photovoltage spectra (TPV) confirmed that the presence of heterojunction accelerated the number of electron transfer, and the recombination of electron and hole was obviously inhibited, so as to participate in oxidation and reduction more. Thus, it makes CeO2@NiAl LDHs heterojunction photocatalyst have high photocatalytic activity for photodegradation of rhodamine B and hydrogen production from water.
Herein, a direct Z-scheme heterojunction CeO2@NiAl-LDHs (LDHs=layered double hydroxides) with core-shell structure was constructed. It shows high oxidative degradation of rhodamine B (36.91 mg·g-1·h-1) and hydrogen production by photoreduction (14.08 mmol·g-1·h-1). Density functional theory (DFT) calculation shows that there was a built-in electric field in the heterojunction, which promotes the electron transfer from LDHs to CeO2. Surface photovoltage spectroscopy (SPV) and transient photovoltage spectra (TPV) confirmed that the presence of heterojunction accelerated the number of electron transfer, and the recombination of electron and hole was obviously inhibited, so as to participate in oxidation and reduction more. Thus, it makes CeO2@NiAl LDHs heterojunction photocatalyst have high photocatalytic activity for photodegradation of rhodamine B and hydrogen production from water.
2021, 37(2): 327-339
doi: 10.11862/CJIC.2021.038
Abstract:
The as-prepared MoSe2/Ag3PO4 by in-situ deposition showed favorable photocatalytic activity and stability. Heterostructure of MoSe2/Ag3PO4 had efficient separation of photogenerated electron-hole pairs that led to the elevated photocatalytic activity. The transfer of photogenerated electrons from the surface of Ag3PO4 to MoSe2 reduced the possibility of Ag+ to metallic Ag. When the mass ratio of MoSe2 and Ag3PO4 was 1:5 (champion combination), the obtained MoSe2/Ag3PO4 could reach to 98% for RhB degradation under visible light irradiation within 30 min. In addition, MoSe2/Ag3PO4 still achieved 89% of the degradation under visible light irradiation after four regenerations. Eventually, the photocatalytic degradation of RhB by MoSe2/Ag3PO4 was revealed by liquid chromatography/mass spectrometry (LC/MS).
The as-prepared MoSe2/Ag3PO4 by in-situ deposition showed favorable photocatalytic activity and stability. Heterostructure of MoSe2/Ag3PO4 had efficient separation of photogenerated electron-hole pairs that led to the elevated photocatalytic activity. The transfer of photogenerated electrons from the surface of Ag3PO4 to MoSe2 reduced the possibility of Ag+ to metallic Ag. When the mass ratio of MoSe2 and Ag3PO4 was 1:5 (champion combination), the obtained MoSe2/Ag3PO4 could reach to 98% for RhB degradation under visible light irradiation within 30 min. In addition, MoSe2/Ag3PO4 still achieved 89% of the degradation under visible light irradiation after four regenerations. Eventually, the photocatalytic degradation of RhB by MoSe2/Ag3PO4 was revealed by liquid chromatography/mass spectrometry (LC/MS).
2021, 37(2): 340-350
doi: 10.11862/CJIC.2021.037
Abstract:
A coordination polymer (CP) and a complex based on H3tbtd/H3bbta and bpy ligands, namely {[Co3(tbtd)2 (bpy)2(H2O)]·5H2O}n (1) and[Cd2(Hbbta)(bpy)3(C2O4)(H2O)] (2) (H3tbtd=4-(2, 4, 6-tricarboxylphenyl)-2, 2', 6', 2″-terpyridine, H3bbta=1-fluoro-2, 4, 6-phenyltriacid, bpy=2, 2'-dipyridine), have been hydrothermal synthesized and structurally characterized by elemental analyses, IR spectroscopy and single-crystal X-ray diffraction analyses. 1 shows 2D network structure, which is linked into 3D supramolecular network through intermolecular hydrogen bonding interactions. 2 is binuclear structure, which is linked by π…π stack interactions and hydrogen bonding interactions to form 2D supramolecular network. CP 1 exhibited photocatalytic activities for degradation of methyl orange (MO) under UV light irradiation and showed good stabilities toward UV-light photocatalysis. In addition, luminescence property of 2 and thermal stabilities of 1~2 were also studied.CCDC: 1986403, 1, 2004223, 2.
A coordination polymer (CP) and a complex based on H3tbtd/H3bbta and bpy ligands, namely {[Co3(tbtd)2 (bpy)2(H2O)]·5H2O}n (1) and[Cd2(Hbbta)(bpy)3(C2O4)(H2O)] (2) (H3tbtd=4-(2, 4, 6-tricarboxylphenyl)-2, 2', 6', 2″-terpyridine, H3bbta=1-fluoro-2, 4, 6-phenyltriacid, bpy=2, 2'-dipyridine), have been hydrothermal synthesized and structurally characterized by elemental analyses, IR spectroscopy and single-crystal X-ray diffraction analyses. 1 shows 2D network structure, which is linked into 3D supramolecular network through intermolecular hydrogen bonding interactions. 2 is binuclear structure, which is linked by π…π stack interactions and hydrogen bonding interactions to form 2D supramolecular network. CP 1 exhibited photocatalytic activities for degradation of methyl orange (MO) under UV light irradiation and showed good stabilities toward UV-light photocatalysis. In addition, luminescence property of 2 and thermal stabilities of 1~2 were also studied.CCDC: 1986403, 1, 2004223, 2.
2021, 37(2): 351-360
doi: 10.11862/CJIC.2021.039
Abstract:
A series of MoO3-GQDs nano-composites with different amounts of graphene quantum dots (GQDs) were prepared by the hydrothermal method. The as-prepared samples were characterized by X-ray diffraction, Scanning electron microscope, Transmission electron microscope, FTIR and so on. The gas sensing properties of MoO3-GQDs were investigated. It was found that the amount of GQDs in the composites had a great influence on the gas response and gas sensing selectivity of the nano-composites. The sensor based on the MoO3-GQDs nano-composite (S-6, the amount of GQDs suspension was 6.0 mL) showed high response and good gas sensing selectivity to TMA at 230℃; the response of the sensor to 1 000 μL·L-1 TMA was 74.08; the response time and recovery time to 1 000 μL·L-1 TMA were 73 and 34 s, respectively; the sensor based on MoO3-GQDs (S-6) composite could detect 1 μL·L-1 TMA vapor at 230℃.
A series of MoO3-GQDs nano-composites with different amounts of graphene quantum dots (GQDs) were prepared by the hydrothermal method. The as-prepared samples were characterized by X-ray diffraction, Scanning electron microscope, Transmission electron microscope, FTIR and so on. The gas sensing properties of MoO3-GQDs were investigated. It was found that the amount of GQDs in the composites had a great influence on the gas response and gas sensing selectivity of the nano-composites. The sensor based on the MoO3-GQDs nano-composite (S-6, the amount of GQDs suspension was 6.0 mL) showed high response and good gas sensing selectivity to TMA at 230℃; the response of the sensor to 1 000 μL·L-1 TMA was 74.08; the response time and recovery time to 1 000 μL·L-1 TMA were 73 and 34 s, respectively; the sensor based on MoO3-GQDs (S-6) composite could detect 1 μL·L-1 TMA vapor at 230℃.
2021, 37(2): 361-367
doi: 10.11862/CJIC.2021.028
Abstract:
Two 2D cobalt(Ⅱ) and manganese(Ⅱ) coordination polymers, namely {[Co(μ3-L)(4, 4'-bipy)]·H2O}n (1) and {[Mn(μ-L)(4, 4'-bipy)(H2O)2]·H2O}n (2), have been constructed hydrothermally using 4-((carboxymethyl)thio)benzoic acid (H2L), 4, 4'-bipyridine(4, 4'-bipy), and cobalt or manganese chlorides. Single-crystal X-ray diffraction analyses reveal that 1 and 2 crystallize in the triclinic and monoclinic systems, space groups P1 and P21/c, respectively. Complexes 1 and 2 show two different 2D sheets composed of dimer Co(Ⅱ) or 1D Mn(Ⅱ) chain units. The structural difference of 1 and 2 is driven by the metal (Ⅱ) nodes. The photocatalytic properties of two complex were investigated, showing that 2 is a promising photocatalyst for the UV-light-driven degradation of methylene blue as a model organic dye pollutant. CCDC: 1967233, 1; 1967234, 2.
Two 2D cobalt(Ⅱ) and manganese(Ⅱ) coordination polymers, namely {[Co(μ3-L)(4, 4'-bipy)]·H2O}n (1) and {[Mn(μ-L)(4, 4'-bipy)(H2O)2]·H2O}n (2), have been constructed hydrothermally using 4-((carboxymethyl)thio)benzoic acid (H2L), 4, 4'-bipyridine(4, 4'-bipy), and cobalt or manganese chlorides. Single-crystal X-ray diffraction analyses reveal that 1 and 2 crystallize in the triclinic and monoclinic systems, space groups P1 and P21/c, respectively. Complexes 1 and 2 show two different 2D sheets composed of dimer Co(Ⅱ) or 1D Mn(Ⅱ) chain units. The structural difference of 1 and 2 is driven by the metal (Ⅱ) nodes. The photocatalytic properties of two complex were investigated, showing that 2 is a promising photocatalyst for the UV-light-driven degradation of methylene blue as a model organic dye pollutant. CCDC: 1967233, 1; 1967234, 2.
2021, 37(2): 368-374
doi: 10.11862/CJIC.2021.027
Abstract:
A new cobalt complex, namely[Co(Hpdc)(bpy)Cl]·C2H5OH (bpy=2, 2'-bipyridine), was synthesized by using pyridine-2, 6-dicarboxylic acid (H2pdc) as ligand under hydrothermal condition, and followed by experimental characterization of infrared spectroscopy and X-ray single-crystal diffraction. To deeply reveal the electronic structure of this complex, density functional theory calculations were employed to investigate its charge distribution, electrostatic potential, frontier molecular orbitals, and relevant electronic properties under aqueous condition. Moreover, the antitumor activity of this complex was evaluated by thiazolyl blue tetrazolium bromide (MTT) assay in chronic myelocytic leukemia (K562) and esophageal carcinoma (OE-19) cancer cell lines, and the resulting IC50 values were estimated to be as low as (0.22±0.05) μg·mL-1 and (0.82±0.16) μg·mL-1 (i. e., (0.48±0.11) μmol·L-1 and (1.77±0.35) μmol·L-1) for K562 and OE-19, respectively, demonstrating its cytotoxic activity against these two cancer cell lines. CCDC: 1994088.
A new cobalt complex, namely[Co(Hpdc)(bpy)Cl]·C2H5OH (bpy=2, 2'-bipyridine), was synthesized by using pyridine-2, 6-dicarboxylic acid (H2pdc) as ligand under hydrothermal condition, and followed by experimental characterization of infrared spectroscopy and X-ray single-crystal diffraction. To deeply reveal the electronic structure of this complex, density functional theory calculations were employed to investigate its charge distribution, electrostatic potential, frontier molecular orbitals, and relevant electronic properties under aqueous condition. Moreover, the antitumor activity of this complex was evaluated by thiazolyl blue tetrazolium bromide (MTT) assay in chronic myelocytic leukemia (K562) and esophageal carcinoma (OE-19) cancer cell lines, and the resulting IC50 values were estimated to be as low as (0.22±0.05) μg·mL-1 and (0.82±0.16) μg·mL-1 (i. e., (0.48±0.11) μmol·L-1 and (1.77±0.35) μmol·L-1) for K562 and OE-19, respectively, demonstrating its cytotoxic activity against these two cancer cell lines. CCDC: 1994088.
2021, 37(2): 375-384
doi: 10.11862/CJIC.2021.033
Abstract:
Three one-dimensional (1D) lanthanide complexes[Ln(HDTTA)3(CH3OH)3]n (Ln=Ce (1), Pr (2), Sm (3)) (D-H2DTTA=(+)-di(p-toluoyl)-D-tartaric acid) were synthesized at room temperature and normal pressure. They were fully structurally characterized by IR, elemental analysis, single-crystal and powder X-ray diffraction. The structure analysis shows that complexes 1~3 are isomorphic. They belong to chiral R3 space group of trigonal system and display infinite 1D chains structure along c axis. Photoluminescence measurements indicated that D-H2DTTA ligand can partly sensitize the f-f transition luminescence of Pr3+ and Sm3+ cations but Ce3+ at 609 nm, which is attributed to the mismatching between the excited state energy levels of metal cations and ligands. Additionally, Complex 1 exhibited photocatalytic property for the degradation of methylene blue under UV light irradiation in the solution. The photocatalytic performance was up to 76% within 160 min without any other reagents. CCDC: 2017862, 1; 2017863, 2; 2017864, 3.
Three one-dimensional (1D) lanthanide complexes[Ln(HDTTA)3(CH3OH)3]n (Ln=Ce (1), Pr (2), Sm (3)) (D-H2DTTA=(+)-di(p-toluoyl)-D-tartaric acid) were synthesized at room temperature and normal pressure. They were fully structurally characterized by IR, elemental analysis, single-crystal and powder X-ray diffraction. The structure analysis shows that complexes 1~3 are isomorphic. They belong to chiral R3 space group of trigonal system and display infinite 1D chains structure along c axis. Photoluminescence measurements indicated that D-H2DTTA ligand can partly sensitize the f-f transition luminescence of Pr3+ and Sm3+ cations but Ce3+ at 609 nm, which is attributed to the mismatching between the excited state energy levels of metal cations and ligands. Additionally, Complex 1 exhibited photocatalytic property for the degradation of methylene blue under UV light irradiation in the solution. The photocatalytic performance was up to 76% within 160 min without any other reagents. CCDC: 2017862, 1; 2017863, 2; 2017864, 3.
