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2023 Volume 39 Issue 6
2023, 39(6): 993-1004
doi: 10.11862/CJIC.2023.074
Abstract:
By tuning the solvothermal reaction conditions, we prepared three Ni(Ⅱ)-based coordination polymers (CPs), namely[Ni(CH3-BDC)(3-TBT)(H2O)2]·EtOH·2H2O (CP1), [Ni3(CH3-BDC)3(3-TBT)2(H2O)5]·2DMF·2H2O (CP2), and[Ni3(CH3-BDC)3(3-TBT)2(H2O)6]·2DMF·4H2O (CP3), where CH3-H2BDC=5-methyl isophthalic acid, 3-TBT=2, 4, 6-tris(3-pyridyl)-1, 3, 5-benzene. X-ray single crystal diffraction analyses reveal that three CPs are constructed from similar Ni2(CH3-BDC)2 binuclear units and exhibited different zero-dimensional (0D), 2D, and 3D networks, respectively. Meanwhile, the catalytic experiments show that CP3 exhibits the best catalytic activities and cycle stability for the oxidative coupling reaction of benzyl alcohol and its derivatives with aniline under solvent-free conditions.
By tuning the solvothermal reaction conditions, we prepared three Ni(Ⅱ)-based coordination polymers (CPs), namely[Ni(CH3-BDC)(3-TBT)(H2O)2]·EtOH·2H2O (CP1), [Ni3(CH3-BDC)3(3-TBT)2(H2O)5]·2DMF·2H2O (CP2), and[Ni3(CH3-BDC)3(3-TBT)2(H2O)6]·2DMF·4H2O (CP3), where CH3-H2BDC=5-methyl isophthalic acid, 3-TBT=2, 4, 6-tris(3-pyridyl)-1, 3, 5-benzene. X-ray single crystal diffraction analyses reveal that three CPs are constructed from similar Ni2(CH3-BDC)2 binuclear units and exhibited different zero-dimensional (0D), 2D, and 3D networks, respectively. Meanwhile, the catalytic experiments show that CP3 exhibits the best catalytic activities and cycle stability for the oxidative coupling reaction of benzyl alcohol and its derivatives with aniline under solvent-free conditions.
2023, 39(6): 1122-1130
doi: 10.11862/CJIC.2023.083
Abstract:
A novel pyrrole-based hydrazone has been synthesized for colorimetric and fluorescent turn-on detection of Hg2+ ions. A 1:1 binding ratio of the Hg2+ complex has been obtained from Job's plots and MS data. The coordination mode was systematically investigated by 1H NMR, time-resolved fluorescence spectroscopy, and density functional theory (DFT) calculations. The limit of detection of 1 for Hg2+ was as low as 45 nmol·L-1 with an association constant of 5.78×108 L·mol-1. It is worth noting that the response of 1 to Hg2+ was good in a pH range of 4.0 to 10.0. In addition, owing to the existence of the morpholine group, the probe can detect lysosomal Hg2+ in HeLa cells.
A novel pyrrole-based hydrazone has been synthesized for colorimetric and fluorescent turn-on detection of Hg2+ ions. A 1:1 binding ratio of the Hg2+ complex has been obtained from Job's plots and MS data. The coordination mode was systematically investigated by 1H NMR, time-resolved fluorescence spectroscopy, and density functional theory (DFT) calculations. The limit of detection of 1 for Hg2+ was as low as 45 nmol·L-1 with an association constant of 5.78×108 L·mol-1. It is worth noting that the response of 1 to Hg2+ was good in a pH range of 4.0 to 10.0. In addition, owing to the existence of the morpholine group, the probe can detect lysosomal Hg2+ in HeLa cells.
2023, 39(6): 1131-1138
doi: 10.11862/CJIC.2023.067
Abstract:
Uniform and dispersed 3D hierarchical nanosheets-assembled ZnO microspheres were fabricated by a simple ethylene glycol (EG)-assisted solvothermal route, in which hexamethylenetetramine (HMTA) was selected as a functional agent. A series of controllable experiments proved that HMTA and the solvent play vital roles in the formation of hierarchical microspheres. The assembly of 2D nanosheets to construct the 3D hierarchical structures not only increases the specific surface area of the products but also builds more charge transport channels. The samples were evaluated as adsorbents for the removal of some organic dyes from the aqueous solution in dark. Resultantly, the hierarchical nanosheets-assembled ZnO microspheres showed excellent removal rate and selectivity for anionic dyes. Taking Congo red (CR) as a representative dye, it can be removed 95.67% after five adsorption cycles due to the synergistic effects of hierarchical structures, large surface areas, and electrostatic attraction. The kinetics studies confirmed that the adsorption of CR onto ZnO microspheres is physisorption and followed the pseudo-second-order kinetic and Langmuir isotherm models.
Uniform and dispersed 3D hierarchical nanosheets-assembled ZnO microspheres were fabricated by a simple ethylene glycol (EG)-assisted solvothermal route, in which hexamethylenetetramine (HMTA) was selected as a functional agent. A series of controllable experiments proved that HMTA and the solvent play vital roles in the formation of hierarchical microspheres. The assembly of 2D nanosheets to construct the 3D hierarchical structures not only increases the specific surface area of the products but also builds more charge transport channels. The samples were evaluated as adsorbents for the removal of some organic dyes from the aqueous solution in dark. Resultantly, the hierarchical nanosheets-assembled ZnO microspheres showed excellent removal rate and selectivity for anionic dyes. Taking Congo red (CR) as a representative dye, it can be removed 95.67% after five adsorption cycles due to the synergistic effects of hierarchical structures, large surface areas, and electrostatic attraction. The kinetics studies confirmed that the adsorption of CR onto ZnO microspheres is physisorption and followed the pseudo-second-order kinetic and Langmuir isotherm models.
2023, 39(6): 1139-1150
doi: 10.11862/CJIC.2023.078
Abstract:
By electrospinning, thermal imidization, and carbonization processes, boron nitride nanosheets (BNNSs) were coated on the surface of carbon fibers (CFs). Thus, BNNSs and CFs can constitute the boron nitride nanosheets/ carbon fibers (BNNSs/CFs) composite to modify commercial polypropylene (PP) separators. The synergetic effect of BNNSs and CFs provides an additional conductive path to cells and serves to localize the soluble polysulfide into the cathode region. As a result, the cell assembled with the 10BNNSs/CFs-PP separator exhibited an initial discharge capacity as high as 1 295.7 mAh·g-1 at 0.05C. Upon increasing the current density to 1C, the cells with 10BNNSs/CFs-PP separators also delivered excellent long-term cycling stability up to 400 cycles and a high final capacity of 583.1 mAh·g-1 with a capacity decay of 0.069% per cycle.
By electrospinning, thermal imidization, and carbonization processes, boron nitride nanosheets (BNNSs) were coated on the surface of carbon fibers (CFs). Thus, BNNSs and CFs can constitute the boron nitride nanosheets/ carbon fibers (BNNSs/CFs) composite to modify commercial polypropylene (PP) separators. The synergetic effect of BNNSs and CFs provides an additional conductive path to cells and serves to localize the soluble polysulfide into the cathode region. As a result, the cell assembled with the 10BNNSs/CFs-PP separator exhibited an initial discharge capacity as high as 1 295.7 mAh·g-1 at 0.05C. Upon increasing the current density to 1C, the cells with 10BNNSs/CFs-PP separators also delivered excellent long-term cycling stability up to 400 cycles and a high final capacity of 583.1 mAh·g-1 with a capacity decay of 0.069% per cycle.
2023, 39(6): 1151-1158
doi: 10.11862/CJIC.2023.069
Abstract:
A Zinc(Ⅱ) metal-organic framework (Zn-MOF), namely [Zn(H2L)(4, 4′-bpy)]n (1), where H4L=1, 1′-ethylbi- phenyl-3, 3′, 5, 5′-tetracarboxylic acid, 4, 4′-bpy=4, 4′-bipyridine, was successfully synthesized under solvothermal conditions. The structure was characterized by single-crystal X-ray diffraction, elemental analysis, and thermogravi- metric analysis. The single crystal structure analysis shows that 1 belongs to the monoclinic C2/c space group and H 2L2- ligands adopt monodentate coordination mode, connecting with Zn(Ⅱ)to form 1D chains. Finally, the 1D chains are connected by 4, 4′-bpy to form a 2D wavelike network. 1 shows good stability in water, and can be used as a highly sensitive and selective fluorescent probe to detect tetracycline (TET) with a detection limit of 0.17 μmol· L-1. 1 can be successfully used for the determination of tetracycline in Yanhe River water. In addition, the possible fluorescence quenching mechanisms of 1 were also studied. CCDC: 2212375, 1.
A Zinc(Ⅱ) metal-organic framework (Zn-MOF), namely [Zn(H2L)(4, 4′-bpy)]n (1), where H4L=1, 1′-ethylbi- phenyl-3, 3′, 5, 5′-tetracarboxylic acid, 4, 4′-bpy=4, 4′-bipyridine, was successfully synthesized under solvothermal conditions. The structure was characterized by single-crystal X-ray diffraction, elemental analysis, and thermogravi- metric analysis. The single crystal structure analysis shows that 1 belongs to the monoclinic C2/c space group and H 2L2- ligands adopt monodentate coordination mode, connecting with Zn(Ⅱ)to form 1D chains. Finally, the 1D chains are connected by 4, 4′-bpy to form a 2D wavelike network. 1 shows good stability in water, and can be used as a highly sensitive and selective fluorescent probe to detect tetracycline (TET) with a detection limit of 0.17 μmol· L-1. 1 can be successfully used for the determination of tetracycline in Yanhe River water. In addition, the possible fluorescence quenching mechanisms of 1 were also studied. CCDC: 2212375, 1.
2023, 39(6): 1159-1168
doi: 10.11862/CJIC.2023.061
Abstract:
In this work, two different morphologies of composites with Cd (Ⅱ) benzimidazole-derived metal-organic framework (MOF) and graphene oxide (GO) were successfully synthesized by adjusting the alkali environments in the one-pot solvothermal process. The structures and properties of these composites were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-visible absorption spectra (UV-Vis), and FT-IR. The adsorption performance of these composites for rhodamine B (RhB) in water was studied. The results showed that GO and Cd-MOF were successfully combined, and the addition of GO enhanced the stability of Cd-MOF in water and improved its adsorption capacity. When the pH value of the solution was 3.5 and the adsorption time was 60 min, the adsorption rate could reach ca. 95%.
In this work, two different morphologies of composites with Cd (Ⅱ) benzimidazole-derived metal-organic framework (MOF) and graphene oxide (GO) were successfully synthesized by adjusting the alkali environments in the one-pot solvothermal process. The structures and properties of these composites were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-visible absorption spectra (UV-Vis), and FT-IR. The adsorption performance of these composites for rhodamine B (RhB) in water was studied. The results showed that GO and Cd-MOF were successfully combined, and the addition of GO enhanced the stability of Cd-MOF in water and improved its adsorption capacity. When the pH value of the solution was 3.5 and the adsorption time was 60 min, the adsorption rate could reach ca. 95%.
2023, 39(6): 1169-1178
doi: 10.11862/CJIC.2023.070
Abstract:
Pt/SAPO-11 catalysts were prepared by impregnation using different polymer dispersants, and their structural and acidic properties were analyzed and characterized using techniques such as X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption-desorption, and NH3 temperature-programmed desorption (TPD).The results showed that the dispersants did not destroy the structure of the catalysts, but instead increased their pore volumes, pore sizes, and specific surface areas, while also changing the acid strengths and acid amounts of the zeolites. Among the dispersants used in our work, polyvinyl pyrrolidone (PVP) treatment resulted in the optimal pore volume, pore size, and acid distribution for the Pt/SAPO-11 catalyst. Evaluation of the catalytic performance of the Pt/SAPO-11 catalysts treated with different dispersants in a fixed-bed reactor showed that the PVP-treated Pt/SAPO-11 catalyst also exhibited the best catalytic performance, with a hydrogenation deoxygenation rate of Jatropha oil up to 99.45%, and bio-aviation kerosene component yield and isoparaffins (C8 -C16) selectivity reaching 44.67% and 56.37%, respectively.
Pt/SAPO-11 catalysts were prepared by impregnation using different polymer dispersants, and their structural and acidic properties were analyzed and characterized using techniques such as X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption-desorption, and NH3 temperature-programmed desorption (TPD).The results showed that the dispersants did not destroy the structure of the catalysts, but instead increased their pore volumes, pore sizes, and specific surface areas, while also changing the acid strengths and acid amounts of the zeolites. Among the dispersants used in our work, polyvinyl pyrrolidone (PVP) treatment resulted in the optimal pore volume, pore size, and acid distribution for the Pt/SAPO-11 catalyst. Evaluation of the catalytic performance of the Pt/SAPO-11 catalysts treated with different dispersants in a fixed-bed reactor showed that the PVP-treated Pt/SAPO-11 catalyst also exhibited the best catalytic performance, with a hydrogenation deoxygenation rate of Jatropha oil up to 99.45%, and bio-aviation kerosene component yield and isoparaffins (C8 -C16) selectivity reaching 44.67% and 56.37%, respectively.
2023, 39(6): 1179-1192
doi: 10.11862/CJIC.2023.081
Abstract:
Nano-phosphor precursors were synthesized with GdPO4 as the matrix and Sm3+ as the activator using the hydrothermal synthesis method. The precursors were calcinated at 800, 900, 1 000, 1 100, and 1 200℃ respectively, thus obtaining GdPO4: Sm3+ phosphors. Firstly, the optimal calcination temperature of GdPO4: Sm3+ was optimized. Then the effect of Sm3+ doping amount on the fluorescence properties of GdPO4: Sm3+ was studied. The hightemperature fluorescence and magnetic properties of the best product were studied in detail. The crystal structure, morphology, luminescence, and magnetic properties of the phosphors were characterized using an X-ray diffractometer (XRD), scanning electron microscope (SEM), magnetometer, and fluorescence spectrophotometer (FL). The results indicate that the crystal structure of phosphors was changed from the precursor GdPO4·H2O: Sm3+ in the hexagonal crystal system to GdPO4: Sm3+ in the monoclinic crystal system. The morphology was changed from nanorods to like-sphere particles. The luminous intensity and phosphorescence lifetime of the phosphors attained their highest levels when the calcination temperature was 1 000℃ and the Sm3+ doping concentration was 2%. The type of energy transferred between Sm3+ in GdPO4: 2%Sm3+ was electric dipole-electric dipole interaction, and the critical distance of energy transfer was about 1.646-1.884 nm. The optimal product GdPO4: 2%Sm3+ had excellent thermal stability, with the thermal quenching activation energy as -0.157 eV. Moreover, it had good paramagnetism, with a mass susceptibility of 1.22×10-4 emu·g-1·Oe-1.
Nano-phosphor precursors were synthesized with GdPO4 as the matrix and Sm3+ as the activator using the hydrothermal synthesis method. The precursors were calcinated at 800, 900, 1 000, 1 100, and 1 200℃ respectively, thus obtaining GdPO4: Sm3+ phosphors. Firstly, the optimal calcination temperature of GdPO4: Sm3+ was optimized. Then the effect of Sm3+ doping amount on the fluorescence properties of GdPO4: Sm3+ was studied. The hightemperature fluorescence and magnetic properties of the best product were studied in detail. The crystal structure, morphology, luminescence, and magnetic properties of the phosphors were characterized using an X-ray diffractometer (XRD), scanning electron microscope (SEM), magnetometer, and fluorescence spectrophotometer (FL). The results indicate that the crystal structure of phosphors was changed from the precursor GdPO4·H2O: Sm3+ in the hexagonal crystal system to GdPO4: Sm3+ in the monoclinic crystal system. The morphology was changed from nanorods to like-sphere particles. The luminous intensity and phosphorescence lifetime of the phosphors attained their highest levels when the calcination temperature was 1 000℃ and the Sm3+ doping concentration was 2%. The type of energy transferred between Sm3+ in GdPO4: 2%Sm3+ was electric dipole-electric dipole interaction, and the critical distance of energy transfer was about 1.646-1.884 nm. The optimal product GdPO4: 2%Sm3+ had excellent thermal stability, with the thermal quenching activation energy as -0.157 eV. Moreover, it had good paramagnetism, with a mass susceptibility of 1.22×10-4 emu·g-1·Oe-1.
2023, 39(6): 1193-1207
doi: 10.11862/CJIC.2023.075
Abstract:
The microstructural defects within the nanowire (NW) have a significant impact on the mechanical properties of the NW. The prediction of the breaking position of the NW has raised concerns owning to it is a crucial point in the application of nanodevices. In this work, based on the statistical analysis, the breaking positions and the positions of the initial microstructural defects generated at the stress yield point are studied separately to analyze their temperature dependence, then further investigate the relationship between the breaking failure and the initial microstructural defects. At the temperature range from 20 to 300 K, including six ensembles, the single - crystal Cu NWs have been performed using molecular dynamics (MD) simulations. The ensemble at each temperature includes 300 independent samples. Based on machine learning, the hexagonal close - packed (hcp) atoms at the stress yield point have been clustered to every initial microstructural defect by the density - based spatial clustering of applications with noise (DBSCAN) algorithm. According to the statistical results, it is found that the initial microstructural defects of NWs simulated in this paper tend to generate at the two ends of the NW while the temperature is less than 50 K. Following the increasing temperature, the MD simulation results have shown a strong temperature dependence of mechanical properties for the single - crystal Cu NWs, including Young′s modulus, average yield stress, average potential energy, etc. It is attributed that there are more initial microstructural defects generated as the increase in temperature, and the positions of initial microstructural defects are averaged out from the two ends of the distribution towards the middle part. The breaking positions for all the simulation temperatures are mainly concentrated on the ends of the NW. The statistical results indicate that this temperature range has little effect on breaking position but a great effect on the initial microstructural defects. It shows a consistency between the initial slip distributions and breaking distributions while the temperature is less than 100 K. However, it has been observed that the differences between them are gradually shown with the increase in temperature due to their different temperature dependents. The microstructural deformation behaviors under different temperatures reveal that the breaking failure is affected by the surface effect and blocking effect of the ends. Based on the results, the final breaking position is correlated to the middle and late stages of the plastic deformation rather than the positions of initial microstructural defects first generated.
The microstructural defects within the nanowire (NW) have a significant impact on the mechanical properties of the NW. The prediction of the breaking position of the NW has raised concerns owning to it is a crucial point in the application of nanodevices. In this work, based on the statistical analysis, the breaking positions and the positions of the initial microstructural defects generated at the stress yield point are studied separately to analyze their temperature dependence, then further investigate the relationship between the breaking failure and the initial microstructural defects. At the temperature range from 20 to 300 K, including six ensembles, the single - crystal Cu NWs have been performed using molecular dynamics (MD) simulations. The ensemble at each temperature includes 300 independent samples. Based on machine learning, the hexagonal close - packed (hcp) atoms at the stress yield point have been clustered to every initial microstructural defect by the density - based spatial clustering of applications with noise (DBSCAN) algorithm. According to the statistical results, it is found that the initial microstructural defects of NWs simulated in this paper tend to generate at the two ends of the NW while the temperature is less than 50 K. Following the increasing temperature, the MD simulation results have shown a strong temperature dependence of mechanical properties for the single - crystal Cu NWs, including Young′s modulus, average yield stress, average potential energy, etc. It is attributed that there are more initial microstructural defects generated as the increase in temperature, and the positions of initial microstructural defects are averaged out from the two ends of the distribution towards the middle part. The breaking positions for all the simulation temperatures are mainly concentrated on the ends of the NW. The statistical results indicate that this temperature range has little effect on breaking position but a great effect on the initial microstructural defects. It shows a consistency between the initial slip distributions and breaking distributions while the temperature is less than 100 K. However, it has been observed that the differences between them are gradually shown with the increase in temperature due to their different temperature dependents. The microstructural deformation behaviors under different temperatures reveal that the breaking failure is affected by the surface effect and blocking effect of the ends. Based on the results, the final breaking position is correlated to the middle and late stages of the plastic deformation rather than the positions of initial microstructural defects first generated.
2023, 39(6): 1005-1013
doi: 10.11862/CJIC.2023.080
Abstract:
An Ag-based metal-organic framework (Ag-MOF) material was successfully synthesized and used for the first time in the electrocatalytic CO2 reduction reaction (CO2RR) by selecting 1, 2, 4-triazole as the ligand with strong electron-donating ability. The crystal structure, morphology, and electrocatalytic CO2RR performance of Ag-MOF were systematically investigated using characterization methods such as powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and chronoamperometry. Compared to commercial Ag nanoparticles, Ag-MOF exhibits superior electrocatalytic CO2RR performance, better stability, and higher catalytic activity. At -0.9 V (vs RHE), the Faraday efficiency of CO achieved 96.1%. When the potential decreased to -1.1 V (vs RHE), the current density could reach 17 mA·cm-2 and the electrode could operate stably for 300 min. It is shown that the chemical environment surrounding the catalytic site can be altered by selecting the appropriate ligand, resulting in the efficient conversion of CO2 to the target product.
An Ag-based metal-organic framework (Ag-MOF) material was successfully synthesized and used for the first time in the electrocatalytic CO2 reduction reaction (CO2RR) by selecting 1, 2, 4-triazole as the ligand with strong electron-donating ability. The crystal structure, morphology, and electrocatalytic CO2RR performance of Ag-MOF were systematically investigated using characterization methods such as powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and chronoamperometry. Compared to commercial Ag nanoparticles, Ag-MOF exhibits superior electrocatalytic CO2RR performance, better stability, and higher catalytic activity. At -0.9 V (vs RHE), the Faraday efficiency of CO achieved 96.1%. When the potential decreased to -1.1 V (vs RHE), the current density could reach 17 mA·cm-2 and the electrode could operate stably for 300 min. It is shown that the chemical environment surrounding the catalytic site can be altered by selecting the appropriate ligand, resulting in the efficient conversion of CO2 to the target product.
2023, 39(6): 1014-1022
doi: 10.11862/CJIC.2023.076
Abstract:
Herein, a novel metal-organic framework {[Co(DTBDA)]2·DMF·MeOH}n (FJI-H37) was prepared by solvothermal reaction of cobalt nitrate with ligand 5, 5'-di(1H-1, 2, 4-triazol-1-yl)-(1, 1'-biphenyl)-2, 2'-dicarboxylic acid (H2DTBDA). FJI-H37 not only has 0.69 nm of micropores for gas adsorption but also possesses good thermal stability and organic solvent tolerance. The gas adsorption tests show that FJI-H37 can not only selectively adsorb C2H2 from a C2H2/CO2 (50:50, V/V) mixture with a relatively high adsorption selectivity of 4.2, but also selectively capture CO2 from a CO2/N2 (15:85, V/V) and CO2/CH4 (50:50, V/V) mixture; which can be further confirmed by the dynamic fixedbed breakthrough experiments.
Herein, a novel metal-organic framework {[Co(DTBDA)]2·DMF·MeOH}n (FJI-H37) was prepared by solvothermal reaction of cobalt nitrate with ligand 5, 5'-di(1H-1, 2, 4-triazol-1-yl)-(1, 1'-biphenyl)-2, 2'-dicarboxylic acid (H2DTBDA). FJI-H37 not only has 0.69 nm of micropores for gas adsorption but also possesses good thermal stability and organic solvent tolerance. The gas adsorption tests show that FJI-H37 can not only selectively adsorb C2H2 from a C2H2/CO2 (50:50, V/V) mixture with a relatively high adsorption selectivity of 4.2, but also selectively capture CO2 from a CO2/N2 (15:85, V/V) and CO2/CH4 (50:50, V/V) mixture; which can be further confirmed by the dynamic fixedbed breakthrough experiments.
2023, 39(6): 1023-1030
doi: 10.11862/CJIC.2023.077
Abstract:
Layered nickel-based cathode materials are of great interest due to their high voltage and specific capacities for sodium ion batteries. However, the Jahn-Teller effect is detrimental for achieving considerable cycling stability at high voltage (4.5 V) and rate capability. Herein, a P2-type Na2/3Mn1/3Bi1/3Ni1/3O2 cathode material was synthesized by adjusting the process conditions of sol-gel, and used as positive active materials to assemble sodium ion battery in air environment. The improved cycling and rate performance under high voltage can be achieved by Mnsubstitution and Bi-substitution. In a wide voltage range of 1.2 to 4.5 V, the material maintained a specific discharge capacity of 90.39 mAh·g-1 after 50 cycles. The cathode obtained a remarkable capacity retention of 96.96% after 50 cycles at 1C (115 mA·g-1) and 80.15% capacity retention up to 850 cycles from 2.0 to 4.0 V. The above data indicate that the cathode materials own an extremely long cycling life and better rate capability.
Layered nickel-based cathode materials are of great interest due to their high voltage and specific capacities for sodium ion batteries. However, the Jahn-Teller effect is detrimental for achieving considerable cycling stability at high voltage (4.5 V) and rate capability. Herein, a P2-type Na2/3Mn1/3Bi1/3Ni1/3O2 cathode material was synthesized by adjusting the process conditions of sol-gel, and used as positive active materials to assemble sodium ion battery in air environment. The improved cycling and rate performance under high voltage can be achieved by Mnsubstitution and Bi-substitution. In a wide voltage range of 1.2 to 4.5 V, the material maintained a specific discharge capacity of 90.39 mAh·g-1 after 50 cycles. The cathode obtained a remarkable capacity retention of 96.96% after 50 cycles at 1C (115 mA·g-1) and 80.15% capacity retention up to 850 cycles from 2.0 to 4.0 V. The above data indicate that the cathode materials own an extremely long cycling life and better rate capability.
2023, 39(6): 1031-1041
doi: 10.11862/CJIC.2023.060
Abstract:
Novel bimetallic (Sn/Ni) doped porous silicon microspheres (pSi@SnNi) were prepared by a simple chemical deposition method, using an inexpensive silicon-aluminum alloy precursor. The three-dimensional porous structure of pSi@SnNi composites can buffer the huge volume expansion of silicon in the lithiation process and increase lithium storage active sites. The deposition and doping of bimetallic (Sn/Ni) may improve the electronic conductivity of Si as well as enhance the structural stability of pSi. Profiting from the unique composition and microstructure, the pSi@SnNi composite with moderate Sn/Ni content showed large reversible lithium storage capacity (2 651.7 mAh·g-1 at 0.1 A·g-1), high electrochemical cycling stability (1 139 mAh·g-1 after 400 cycles at 1 A·g-1), and excellent rate capability (1 235.8 mAh·g-1 at 2.5 A·g-1).
Novel bimetallic (Sn/Ni) doped porous silicon microspheres (pSi@SnNi) were prepared by a simple chemical deposition method, using an inexpensive silicon-aluminum alloy precursor. The three-dimensional porous structure of pSi@SnNi composites can buffer the huge volume expansion of silicon in the lithiation process and increase lithium storage active sites. The deposition and doping of bimetallic (Sn/Ni) may improve the electronic conductivity of Si as well as enhance the structural stability of pSi. Profiting from the unique composition and microstructure, the pSi@SnNi composite with moderate Sn/Ni content showed large reversible lithium storage capacity (2 651.7 mAh·g-1 at 0.1 A·g-1), high electrochemical cycling stability (1 139 mAh·g-1 after 400 cycles at 1 A·g-1), and excellent rate capability (1 235.8 mAh·g-1 at 2.5 A·g-1).
2023, 39(6): 1042-1052
doi: 10.11862/CJIC.2023.085
Abstract:
A single-crystal truncated octahedral morphology LiZn0.08Al0.01Mn1.91O4 cathode material with {111}, {110}, and {100} crystal surfaces was synthesized by a solid-state combustion method. The results show that Zn-Al co-doped promotes the crystal development and the selective growth of crystal surfaces of spinel LiMn2O4 materials, while forming single-crystal truncated octahedral grain. The Zn-Al co-doped sample effectively inhibits the JahnTeller effect and reduces Mn dissolution, thus enhancing the crystal structure stability and significantly improving the electrochemical performance. The initial discharge specific capacity of LiZn0.08Al0.01Mn1.91O4 were 92.6 and 76.5 mAh·g-1 at 5C and 10C, the corresponding capacity retention remained 70.4% and 74.8% after 2 000 cycles, respectively. Even at a high current density of 15C, the initial discharge capacity was still 64.2 mAh·g-1, and the capacity retention can reach 82.2% after 800th cycles. Compared with LiZn0.08Mn1.92O4, the LiZn0.08Al0.01Mn1.91O4 cathode material had a larger Li+ diffusion coefficient (1.02×10-11 cm2·s-1) and smaller apparent activation energy (25.60kJ mol-1). The results show that the Zn-Al co-doped and monocrystalline morphology control strategy can reduce the energy barrier of Li+ during the de-intercalation process and increase the diffusion rate in electrode materials.
A single-crystal truncated octahedral morphology LiZn0.08Al0.01Mn1.91O4 cathode material with {111}, {110}, and {100} crystal surfaces was synthesized by a solid-state combustion method. The results show that Zn-Al co-doped promotes the crystal development and the selective growth of crystal surfaces of spinel LiMn2O4 materials, while forming single-crystal truncated octahedral grain. The Zn-Al co-doped sample effectively inhibits the JahnTeller effect and reduces Mn dissolution, thus enhancing the crystal structure stability and significantly improving the electrochemical performance. The initial discharge specific capacity of LiZn0.08Al0.01Mn1.91O4 were 92.6 and 76.5 mAh·g-1 at 5C and 10C, the corresponding capacity retention remained 70.4% and 74.8% after 2 000 cycles, respectively. Even at a high current density of 15C, the initial discharge capacity was still 64.2 mAh·g-1, and the capacity retention can reach 82.2% after 800th cycles. Compared with LiZn0.08Mn1.92O4, the LiZn0.08Al0.01Mn1.91O4 cathode material had a larger Li+ diffusion coefficient (1.02×10-11 cm2·s-1) and smaller apparent activation energy (25.60kJ mol-1). The results show that the Zn-Al co-doped and monocrystalline morphology control strategy can reduce the energy barrier of Li+ during the de-intercalation process and increase the diffusion rate in electrode materials.
2023, 39(6): 1053-1060
doi: 10.11862/CJIC.2023.066
Abstract:
To solve the problem of the electrochemical performance of lithium-rich manganese ternary cathode material (Li1.2Ni0.133Co0.133Mn0.533O2, LR) with poor cyclic stability at high temperatures, the materials modified with Al2O3, AlF3, and AlPO4 were prepared by simple multi-phase recombination. X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and electrochemical impedance spectroscopy (EIS) were used to study the composition structure, electrochemical properties, and mechanism of the composite materials at high temperatures. The results showed that the Li1.2Ni0.133Co0.133Mn0.533O2 modified with Al2O3 (LRO) had the best properties and the coating layer was thin and uniform. At 50℃, the average discharge capacity of LRO was 189.5 mAh·g-1 for 200 cycles, and the capacity retention rate was 81.5%, which was 61.5 mAh·g-1 and 49.8% higher than that of raw materials, respectively. The charge transfer resistance of LRO after 100 cycles was 443.1 Ω, only half of the raw materials, showing excellent electrochemical performance.
To solve the problem of the electrochemical performance of lithium-rich manganese ternary cathode material (Li1.2Ni0.133Co0.133Mn0.533O2, LR) with poor cyclic stability at high temperatures, the materials modified with Al2O3, AlF3, and AlPO4 were prepared by simple multi-phase recombination. X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and electrochemical impedance spectroscopy (EIS) were used to study the composition structure, electrochemical properties, and mechanism of the composite materials at high temperatures. The results showed that the Li1.2Ni0.133Co0.133Mn0.533O2 modified with Al2O3 (LRO) had the best properties and the coating layer was thin and uniform. At 50℃, the average discharge capacity of LRO was 189.5 mAh·g-1 for 200 cycles, and the capacity retention rate was 81.5%, which was 61.5 mAh·g-1 and 49.8% higher than that of raw materials, respectively. The charge transfer resistance of LRO after 100 cycles was 443.1 Ω, only half of the raw materials, showing excellent electrochemical performance.
2023, 39(6): 1061-1071
doi: 10.11862/CJIC.2023.084
Abstract:
To simplify the fabrication procedures and improve the film quality, herein we used a bi-solvent system containing water and ethylene glycol methyl ether (EGME), which is less toxic and environmentally friendly. The bi-solvent (Volume ratio: 1:1) can dissolve CsBr and improve the solubility of CsBr, decreasing rapidly the spinning times of CsBr methanol solution and streamlining immensely multistep processes into a classical two-step methodology. The results from scanning electron microscopy (SEM) images and X-ray diffraction (XRD) patterns verify the formation of a compact, homogeneous, and uniform CsPbBr3 film by the bi-solvent system. Based on this bi-solvent system, the ideal parameters during the film deposition were also discovered. In addition, we notice that the CsPbBr3 film still existed in some large-size random phases, which can be deducted as the excessive CsPb2Br5 phase through XRD patterns. For further perfection, we explore the influence of CsBr methanol solution spinning times right after the modified two-step process. The subsequently-spinning CsBr can act as a surface modifier to diminish the undesired impurity, thus enhancing the film quality and the efficiency of as-constructed CsPbBr3-based perovskite solar cells (PSCs). As a result, CsPbBr3-based PSCs, prepared by spinning coating one time with a water/EGME solution and two times with the methanol solution of CsBr, had the optimal performance. It can reach open-circuit voltage (VOC), short circuit current density (JSC), fill factor (FF) of 1.44 V, 6.26 mA·cm-2, 74.57%, and the ultimate photoelectric conversion efficiency (PCE) attained 6.72%.
To simplify the fabrication procedures and improve the film quality, herein we used a bi-solvent system containing water and ethylene glycol methyl ether (EGME), which is less toxic and environmentally friendly. The bi-solvent (Volume ratio: 1:1) can dissolve CsBr and improve the solubility of CsBr, decreasing rapidly the spinning times of CsBr methanol solution and streamlining immensely multistep processes into a classical two-step methodology. The results from scanning electron microscopy (SEM) images and X-ray diffraction (XRD) patterns verify the formation of a compact, homogeneous, and uniform CsPbBr3 film by the bi-solvent system. Based on this bi-solvent system, the ideal parameters during the film deposition were also discovered. In addition, we notice that the CsPbBr3 film still existed in some large-size random phases, which can be deducted as the excessive CsPb2Br5 phase through XRD patterns. For further perfection, we explore the influence of CsBr methanol solution spinning times right after the modified two-step process. The subsequently-spinning CsBr can act as a surface modifier to diminish the undesired impurity, thus enhancing the film quality and the efficiency of as-constructed CsPbBr3-based perovskite solar cells (PSCs). As a result, CsPbBr3-based PSCs, prepared by spinning coating one time with a water/EGME solution and two times with the methanol solution of CsBr, had the optimal performance. It can reach open-circuit voltage (VOC), short circuit current density (JSC), fill factor (FF) of 1.44 V, 6.26 mA·cm-2, 74.57%, and the ultimate photoelectric conversion efficiency (PCE) attained 6.72%.
2023, 39(6): 1072-1078
doi: 10.11862/CJIC.2023.073
Abstract:
The reactions of a racemic four-coordinated macrocyclic nickel(Ⅱ) complex[Ni(rac-L)](ClO4)2 with l- and d-mandelic acid anion in acetonitrile/water gave six-coordinated enantiomers of[Ni(RR-L) (S-Man)]ClO4 (1) and[Ni(SS-L)(R-Man)]ClO4 (2) (L=5, 5, 7, 12, 12, 14-hexamethyl-1, 4, 8, 11-tetraazacyclotetradecane, Man=mandelic acid), respectively. The reaction of[Ni(rac-L)](ClO4)2 with dl-Man- gave a conglomerate, in which the RR and SS enantiomers preferentially coordinate to l- and d-Man- respectively to give a racemic mixture of 1 and 2, and the chiral recognition occurs during the reaction, in which each crystal crystallizes into enantiopure. The reactions of[Ni(rac-L)] (ClO4)2 with dl-2-phenylpropionic acid and tropic acid anion gave complexes[Ni(rac-L)(dl-PPA)]ClO4 (3) (PPA=2-phenylpropionic acid) and[Ni(rac-L)(dl-Tro)]ClO4 (4) (Tro=tropic acid), respectively. Single-crystal X-ray diffraction analyses show that the Ni (Ⅱ) ions display an octahedral coordination geometry by coordination with four nitrogen atoms of macrocyclic ligand in a folded configuration, plus two oxygen atoms of carboxyl and hydroxyl for 1 and 2, or two oxygen atoms of carboxyl for 3 and 4 in cis-position. Complexes 1 and 2 belong to a pair of enantiomers, which are constructed via hydrogen bonding linking of[Ni(RR-L)(S-Man)]+ and[Ni(SS-L)(R-Man)]+ monomers to form 1D hydrogen bonded zigzag chain, respectively. The homochiral natures of 1 and 2 are confirmed by the results of circular dichroism (CD) spectra measurements.
The reactions of a racemic four-coordinated macrocyclic nickel(Ⅱ) complex[Ni(rac-L)](ClO4)2 with l- and d-mandelic acid anion in acetonitrile/water gave six-coordinated enantiomers of[Ni(RR-L) (S-Man)]ClO4 (1) and[Ni(SS-L)(R-Man)]ClO4 (2) (L=5, 5, 7, 12, 12, 14-hexamethyl-1, 4, 8, 11-tetraazacyclotetradecane, Man=mandelic acid), respectively. The reaction of[Ni(rac-L)](ClO4)2 with dl-Man- gave a conglomerate, in which the RR and SS enantiomers preferentially coordinate to l- and d-Man- respectively to give a racemic mixture of 1 and 2, and the chiral recognition occurs during the reaction, in which each crystal crystallizes into enantiopure. The reactions of[Ni(rac-L)] (ClO4)2 with dl-2-phenylpropionic acid and tropic acid anion gave complexes[Ni(rac-L)(dl-PPA)]ClO4 (3) (PPA=2-phenylpropionic acid) and[Ni(rac-L)(dl-Tro)]ClO4 (4) (Tro=tropic acid), respectively. Single-crystal X-ray diffraction analyses show that the Ni (Ⅱ) ions display an octahedral coordination geometry by coordination with four nitrogen atoms of macrocyclic ligand in a folded configuration, plus two oxygen atoms of carboxyl and hydroxyl for 1 and 2, or two oxygen atoms of carboxyl for 3 and 4 in cis-position. Complexes 1 and 2 belong to a pair of enantiomers, which are constructed via hydrogen bonding linking of[Ni(RR-L)(S-Man)]+ and[Ni(SS-L)(R-Man)]+ monomers to form 1D hydrogen bonded zigzag chain, respectively. The homochiral natures of 1 and 2 are confirmed by the results of circular dichroism (CD) spectra measurements.
2023, 39(6): 1079-1090
doi: 10.11862/CJIC.2023.068
Abstract:
To solve the major defects of SiOx-based anode materials, composite materials with different Si-Fe content and SnO2 were deliberately prepared via a tandem strategy involving mechanical ball milling, spray drying, and high-temperature pyrolysis in this paper. Furthermore, the phase structures, microscopic morphologies, and electrochemical properties of as-obtained materials were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive spectroscopy (EDS), and galvanostatic charge-discharge test system. The electrochemical results show that the composite containing a mass fraction of 5% Si-Fe possesses a relatively good comprehensive electrochemical performance with a charging capacity of 443.4 mAh·g-1 and the first Coulombic efficiency of 75.2%. After 310 cycles, the charging capacity still retained 369.1 mAh·g-1, and the capacity retention rate was up to 81.0%. Meanwhile, the lithium diffusion rate is remarkably improved after Si-Fe incorporation.
To solve the major defects of SiOx-based anode materials, composite materials with different Si-Fe content and SnO2 were deliberately prepared via a tandem strategy involving mechanical ball milling, spray drying, and high-temperature pyrolysis in this paper. Furthermore, the phase structures, microscopic morphologies, and electrochemical properties of as-obtained materials were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive spectroscopy (EDS), and galvanostatic charge-discharge test system. The electrochemical results show that the composite containing a mass fraction of 5% Si-Fe possesses a relatively good comprehensive electrochemical performance with a charging capacity of 443.4 mAh·g-1 and the first Coulombic efficiency of 75.2%. After 310 cycles, the charging capacity still retained 369.1 mAh·g-1, and the capacity retention rate was up to 81.0%. Meanwhile, the lithium diffusion rate is remarkably improved after Si-Fe incorporation.
2023, 39(6): 1091-1102
doi: 10.11862/CJIC.2023.072
Abstract:
In this work, we applied a simple hydrothermal method to grow a Mo-doped NiMnSe2 without binding reagent on the foam nickel (noted as Ni0.8Mo0.2MnSe2). Small amount of Mo substitution for Ni can provide rich reactive sites and therefore greatly enhances the electrochemical performance of NiMnSe2. The specific capacity of Ni0.8Mo0.2MnSe2 at 1 A·g-1 reached 1 404.0 F·g-1. Mo substitution can also decrease the charge transfer resistance and diffusion resistance as well as improve the stability of the material structure. The Ni0.8Mo0.2MnSe2//AC (activated carbon) hybrid supercapacitor (HSC) delivered capacity of 81.6 F·g-1 and exhibited excellent rate performance. After 10 000 cycles at 2 A·g-1, the Ni0.8Mo0.2MnSe2//AC HSC maintained 95.8% of the capacity, indicating a high cycling stability. Under the power density of 376.6 W·kg-1, the Ni0.8Mo0.2MnSe2//AC HSC showed an energy density of 25.5 Wh·kg-1, higher than those of other similar supercapacitor, implying a high energy storage ability.
In this work, we applied a simple hydrothermal method to grow a Mo-doped NiMnSe2 without binding reagent on the foam nickel (noted as Ni0.8Mo0.2MnSe2). Small amount of Mo substitution for Ni can provide rich reactive sites and therefore greatly enhances the electrochemical performance of NiMnSe2. The specific capacity of Ni0.8Mo0.2MnSe2 at 1 A·g-1 reached 1 404.0 F·g-1. Mo substitution can also decrease the charge transfer resistance and diffusion resistance as well as improve the stability of the material structure. The Ni0.8Mo0.2MnSe2//AC (activated carbon) hybrid supercapacitor (HSC) delivered capacity of 81.6 F·g-1 and exhibited excellent rate performance. After 10 000 cycles at 2 A·g-1, the Ni0.8Mo0.2MnSe2//AC HSC maintained 95.8% of the capacity, indicating a high cycling stability. Under the power density of 376.6 W·kg-1, the Ni0.8Mo0.2MnSe2//AC HSC showed an energy density of 25.5 Wh·kg-1, higher than those of other similar supercapacitor, implying a high energy storage ability.
2023, 39(6): 1103-1112
doi: 10.11862/CJIC.2023.082
Abstract:
In the study, by hydrothermal method, FeOOH nano-materials were grown on the surface of black phosphorus (BP) nanosheets to prepare FeOOH/BP composite. As an oxygen evolution reaction (OER) electrocatalyst, its overpotential was only 191 mV at the current density of 20 mA·cm-2, with a Tafel slope of 49.9 mV·dec-1. After 1 000 cycles, its overpotential only increased by 3 mV, showing the best stability. FeOOH was loaded on the BP surface, which can hinder BP oxidation and enhance its carrier conduction ability. And the loaded nano-FeOOH had a small scale and a weak crystalline nature, which is conducive to enriching their active site and increasing the active area. The synergy of this binary system is the main reason for the OER performance improvement. By comparison, it was found that the active area of FeOOH/BP reached 26.9 mF·cm-2, which was 2.3 times that of pure FeOOH (11.8 mF·cm-2) and 1.6 times that of pure BP nanosheets (16.8 mF·cm-2). The excellent activity of this composite material is not only attributed to the morphology change of FeOOH, which significantly expands its effective active area but also benefits from the encapsulated BP, which has better dispersion and stronger conductivity.
In the study, by hydrothermal method, FeOOH nano-materials were grown on the surface of black phosphorus (BP) nanosheets to prepare FeOOH/BP composite. As an oxygen evolution reaction (OER) electrocatalyst, its overpotential was only 191 mV at the current density of 20 mA·cm-2, with a Tafel slope of 49.9 mV·dec-1. After 1 000 cycles, its overpotential only increased by 3 mV, showing the best stability. FeOOH was loaded on the BP surface, which can hinder BP oxidation and enhance its carrier conduction ability. And the loaded nano-FeOOH had a small scale and a weak crystalline nature, which is conducive to enriching their active site and increasing the active area. The synergy of this binary system is the main reason for the OER performance improvement. By comparison, it was found that the active area of FeOOH/BP reached 26.9 mF·cm-2, which was 2.3 times that of pure FeOOH (11.8 mF·cm-2) and 1.6 times that of pure BP nanosheets (16.8 mF·cm-2). The excellent activity of this composite material is not only attributed to the morphology change of FeOOH, which significantly expands its effective active area but also benefits from the encapsulated BP, which has better dispersion and stronger conductivity.
2023, 39(6): 1113-1121
doi: 10.11862/CJIC.2023.071
Abstract:
In this work, a series of ZnAl2O 4∶xMn samples were successfully prepared by the co - precipitation and calcination methods. The micrographs and phases of powders were analyzed by scanning electron microscopy and X-ray diffraction, respectively. The octahedral position of [AlO6] in ZnAl2O4 with spinel structure can be effectively replaced by Mn4+. The photoluminescence excitation (PLE) spectra and photoluminescence emission (PL) spectra of ZnAl2O4∶xMn with varying Mn4+ doping concentrations (molar ratios of Mn to Al) were investigated. The crystal structure of host material ZnAl2O4 is conducive to effective luminescence of Mn4+ at 680 nm. The optimum doping concentration of Mn4+ was 0.06%. The relationship between luminescence intensity and concentration was analyzed by the Dexter formula to explore the mechanism of concentration quenching. The energy transfer among the nearest neighbor ions leads to concentration quenching. To further improve the luminous intensity of Mn4+, seven metal ions (Li+, Na+, K+, Ca2+, Sr2+, Sn2+, and Ga3+) were co-doped with Mn4+ into the ZnAl2O 4 crystal structure. PL spectra indicated that the co-doping effect could remarkably enhance the luminescent intensity of Mn4+. The relative prominent co-doping of Li+ and Ga3+ with Mn4+ enhanced the luminous intensity of Mn4+ by 0.6 times and doubled, respectively. Furthermore, the concentration quenching of Mn4+ is delayed.
In this work, a series of ZnAl2O 4∶xMn samples were successfully prepared by the co - precipitation and calcination methods. The micrographs and phases of powders were analyzed by scanning electron microscopy and X-ray diffraction, respectively. The octahedral position of [AlO6] in ZnAl2O4 with spinel structure can be effectively replaced by Mn4+. The photoluminescence excitation (PLE) spectra and photoluminescence emission (PL) spectra of ZnAl2O4∶xMn with varying Mn4+ doping concentrations (molar ratios of Mn to Al) were investigated. The crystal structure of host material ZnAl2O4 is conducive to effective luminescence of Mn4+ at 680 nm. The optimum doping concentration of Mn4+ was 0.06%. The relationship between luminescence intensity and concentration was analyzed by the Dexter formula to explore the mechanism of concentration quenching. The energy transfer among the nearest neighbor ions leads to concentration quenching. To further improve the luminous intensity of Mn4+, seven metal ions (Li+, Na+, K+, Ca2+, Sr2+, Sn2+, and Ga3+) were co-doped with Mn4+ into the ZnAl2O 4 crystal structure. PL spectra indicated that the co-doping effect could remarkably enhance the luminescent intensity of Mn4+. The relative prominent co-doping of Li+ and Ga3+ with Mn4+ enhanced the luminous intensity of Mn4+ by 0.6 times and doubled, respectively. Furthermore, the concentration quenching of Mn4+ is delayed.
