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2025 Volume 41 Issue 2
2025, 41(2): 225-234
doi: 10.11862/CJIC.20240224
Abstract:
This work investigated the deep dehydration process of ethanol solvent by vapor permeation technique of hollow fiber supported NaA zeolite membrane using the combined operations of N2 sweeping and vacuum suction. The results indicated sweeping gas plays a dominant role in the deep dehydration of ethanol. Compared with the case without any sweeping (under an operation temperature of 100 ℃ and a feeding liquid flow rate of 30 mL·min-1), the N2 sweeping with a flow rate of 60 mL·min-1 could promote the membrane dehydration efficiency by several folds, where the production efficiency was enhanced by 43% to obtain the ethanol with ultra-low water content of 0.04%. For a higher operation temperature of 120 ℃, the water content in ethanol could be further reduced to 0.068‰ when the feeding liquid flow rate increased to 50 mL·min-1, where the harvest percentage was high up to 99.86%.
This work investigated the deep dehydration process of ethanol solvent by vapor permeation technique of hollow fiber supported NaA zeolite membrane using the combined operations of N2 sweeping and vacuum suction. The results indicated sweeping gas plays a dominant role in the deep dehydration of ethanol. Compared with the case without any sweeping (under an operation temperature of 100 ℃ and a feeding liquid flow rate of 30 mL·min-1), the N2 sweeping with a flow rate of 60 mL·min-1 could promote the membrane dehydration efficiency by several folds, where the production efficiency was enhanced by 43% to obtain the ethanol with ultra-low water content of 0.04%. For a higher operation temperature of 120 ℃, the water content in ethanol could be further reduced to 0.068‰ when the feeding liquid flow rate increased to 50 mL·min-1, where the harvest percentage was high up to 99.86%.
2025, 41(2): 235-244
doi: 10.11862/CJIC.20240311
Abstract:
To study the effect of substituents on the photo-physical properties of iridium phosphorescent complexes, four identical methyl (Me), methoxy (MeO), fluorine (F), or trifluoromethyl (CF3) groups were introduced into the 2and 4-positions of the two phenyl groups onto the 2, 4-bis(2, 4-disubstituted phenyl) pyridine [2, 4-(2, 4-2R-phenyl)2py, R=Me (HL1), MeO (HL2), F (HL3), CF3 (HL4)] main ligands at the same time. Four iridium phosphorescent complexes (Ln)2Ir(acac) [n=1 (Ir1), 2 (Ir2), 3 (Ir3), 4(Ir4)] were synthesized by using HL1, HL2, HL3, or HL4 as the main ligand and acetylacetone (Hacac) as the auxiliary ligand. The composition, spatial structure, and molecular stacking of all iridium phosphorescent complexes were characterized by elemental analysis, nuclear magnetic resonance spectroscopy (1H NMR and 13C NMR), and single-crystal X-ray diffraction. The results indicated that all four iridium phosphorescent complexes exhibit slightly distorted octahedral configurations. The central iridium(Ⅲ) coordinates with the C and N atoms of the two main ligands to form a five-membered chelating ring while coordinating with the two oxygen atoms of the acetylacetone auxiliary ligand to form a stable six-membered chelating ring. The results are consistent with the chemical structure of the target compound. A comprehensive and systematic study was conducted on the photophysical properties of iridium phosphorescent complexes through solution and solid photoluminescence spectroscopy, UV Vis absorption spectroscopy, fluorescence lifetime, and theoretical calculations. The complexes Ir1, Ir2, Ir3, and Ir4 in solution with the photoluminescence quantum yields of 68%, 83%, 88%, and 81% exhibited maximum emission peaks at 537, 515, 514, and 553 nm, fluorescence lifetime of 26.75, 163.93, 64.50, and 330.39 ns, and in solid with maximum emission peaks at 536, 520, 520, and 546 nm, respectively. Four iridium phosphorescent complexes have different electron cloud distribution characteristics, and substituents can regulate the distribution of electron clouds on the benzene ring, further achieving the control of photophysical properties and chemical structure, such as emission wavelength in solution and solid-state, emission color, fluorescence lifetime, and molecular stacking.
To study the effect of substituents on the photo-physical properties of iridium phosphorescent complexes, four identical methyl (Me), methoxy (MeO), fluorine (F), or trifluoromethyl (CF3) groups were introduced into the 2and 4-positions of the two phenyl groups onto the 2, 4-bis(2, 4-disubstituted phenyl) pyridine [2, 4-(2, 4-2R-phenyl)2py, R=Me (HL1), MeO (HL2), F (HL3), CF3 (HL4)] main ligands at the same time. Four iridium phosphorescent complexes (Ln)2Ir(acac) [n=1 (Ir1), 2 (Ir2), 3 (Ir3), 4(Ir4)] were synthesized by using HL1, HL2, HL3, or HL4 as the main ligand and acetylacetone (Hacac) as the auxiliary ligand. The composition, spatial structure, and molecular stacking of all iridium phosphorescent complexes were characterized by elemental analysis, nuclear magnetic resonance spectroscopy (1H NMR and 13C NMR), and single-crystal X-ray diffraction. The results indicated that all four iridium phosphorescent complexes exhibit slightly distorted octahedral configurations. The central iridium(Ⅲ) coordinates with the C and N atoms of the two main ligands to form a five-membered chelating ring while coordinating with the two oxygen atoms of the acetylacetone auxiliary ligand to form a stable six-membered chelating ring. The results are consistent with the chemical structure of the target compound. A comprehensive and systematic study was conducted on the photophysical properties of iridium phosphorescent complexes through solution and solid photoluminescence spectroscopy, UV Vis absorption spectroscopy, fluorescence lifetime, and theoretical calculations. The complexes Ir1, Ir2, Ir3, and Ir4 in solution with the photoluminescence quantum yields of 68%, 83%, 88%, and 81% exhibited maximum emission peaks at 537, 515, 514, and 553 nm, fluorescence lifetime of 26.75, 163.93, 64.50, and 330.39 ns, and in solid with maximum emission peaks at 536, 520, 520, and 546 nm, respectively. Four iridium phosphorescent complexes have different electron cloud distribution characteristics, and substituents can regulate the distribution of electron clouds on the benzene ring, further achieving the control of photophysical properties and chemical structure, such as emission wavelength in solution and solid-state, emission color, fluorescence lifetime, and molecular stacking.
2025, 41(2): 245-253
doi: 10.11862/CJIC.20240307
Abstract:
Herein, a two dimensional europium based metal organic framework [Eu(dtztp)0.5(H2dtztp)0.5(DMF)3] · 0.113H2O (Eu -MOF) was obtained through self assembly of 2, 5 bis(2H tetrazol 5 yl) terephthalic acid ligand (H4dtztp) with Eu3+ under solvent thermal conditions, where DMF is N, N-dimethylformamide. The spatial structure, phase purity, and thermal stability of Eu-MOF were characterized by single-crystal X-ray diffraction, powder X-ray diffraction, elemental analysis, and thermogravimetric analysis. Meanwhile, the solid-state fluorescence and antibiotic detection functions of Eu-MOF were also investigated. The results show that Eu-MOF crystallizes in triclinic system,\begin{document}$P \overline{1}$\end{document}
Herein, a two dimensional europium based metal organic framework [Eu(dtztp)0.5(H2dtztp)0.5(DMF)3] · 0.113H2O (Eu -MOF) was obtained through self assembly of 2, 5 bis(2H tetrazol 5 yl) terephthalic acid ligand (H4dtztp) with Eu3+ under solvent thermal conditions, where DMF is N, N-dimethylformamide. The spatial structure, phase purity, and thermal stability of Eu-MOF were characterized by single-crystal X-ray diffraction, powder X-ray diffraction, elemental analysis, and thermogravimetric analysis. Meanwhile, the solid-state fluorescence and antibiotic detection functions of Eu-MOF were also investigated. The results show that Eu-MOF crystallizes in triclinic system,
2025, 41(2): 254-266
doi: 10.11862/CJIC.20240260
Abstract:
Two surface and interface engineering strategies were developed, i.e., the TiO2@Al2O3 oxide dual coating in a heterostructure and binary Ti#Al based cation co-doping in a gradient surface enrichment to modify NaNi1/3Fe1/3Mn1/3O2 (NFM) cathode material using atomic layered deposition (ALD) and high-temperature annealing runaway temperatures to 285.9 and 289.5 ℃ on the fully-charged condition respectively, corresponding to the increment of 6.1 and 9.7 ℃ compared to the NFM via differential scanning calorimetric (DSC) measurements. In-situ differential electrochemical mass spectrometry (DEMS) was further employed to analyze gas components and corresponding contents in the first two cycles of three different cathodes. As a result, the surface coating benefits from restricting the generation of major H2 components by effectively suppressing the protonation of the electrolyte solvents. By contrast, the lattice doping works for impeding the follow-up reactions of decomposed products from the initial decomposition of electrolytes. process, and their effects on improving electrochemical performance and thermal stability of the NFM cathode, and suppressing gas generation during its sodiation/desodiation were also evaluated. When the capacity reached 60% of the capacity of the second cycle in a voltage range of 2.0-4.0 V (vs Na/Na+) at a high current density of 1C (120 mA· g-1), the surface-coated NFM@TiO2(10)@Al2O3(10) and lattice-doped NFM#Ti(35)#Al(10) cathodes (the number in parentheses responds to the cycles for ALD deposition) could maintain 319 and 358 cycles, respectively, more than that of the unmodified NFM cathode (250 cycles). Moreover, two modified cathodes also underwent their thermal runaway temperatures to 285.9 and 289.5 ℃ on the fully-charged condition respectively, corresponding to the increment of 6.1 and 9.7 ℃ compared to the NFM via differential scanning calorimetric (DSC) measurements. In-situ differential electrochemical mass spectrometry (DEMS) was further employed to analyze gas components and corresponding contents in the first two cycles of three different cathodes. As a result, the surface coating benefits from restricting the generation of major H2 components by effectively suppressing the protonation of the electrolyte solvents.By contrast, the lattice doping works for impeding the follow-up reactions of decomposed products from the initial decomposition of electrolytes.
Two surface and interface engineering strategies were developed, i.e., the TiO2@Al2O3 oxide dual coating in a heterostructure and binary Ti#Al based cation co-doping in a gradient surface enrichment to modify NaNi1/3Fe1/3Mn1/3O2 (NFM) cathode material using atomic layered deposition (ALD) and high-temperature annealing runaway temperatures to 285.9 and 289.5 ℃ on the fully-charged condition respectively, corresponding to the increment of 6.1 and 9.7 ℃ compared to the NFM via differential scanning calorimetric (DSC) measurements. In-situ differential electrochemical mass spectrometry (DEMS) was further employed to analyze gas components and corresponding contents in the first two cycles of three different cathodes. As a result, the surface coating benefits from restricting the generation of major H2 components by effectively suppressing the protonation of the electrolyte solvents. By contrast, the lattice doping works for impeding the follow-up reactions of decomposed products from the initial decomposition of electrolytes. process, and their effects on improving electrochemical performance and thermal stability of the NFM cathode, and suppressing gas generation during its sodiation/desodiation were also evaluated. When the capacity reached 60% of the capacity of the second cycle in a voltage range of 2.0-4.0 V (vs Na/Na+) at a high current density of 1C (120 mA· g-1), the surface-coated NFM@TiO2(10)@Al2O3(10) and lattice-doped NFM#Ti(35)#Al(10) cathodes (the number in parentheses responds to the cycles for ALD deposition) could maintain 319 and 358 cycles, respectively, more than that of the unmodified NFM cathode (250 cycles). Moreover, two modified cathodes also underwent their thermal runaway temperatures to 285.9 and 289.5 ℃ on the fully-charged condition respectively, corresponding to the increment of 6.1 and 9.7 ℃ compared to the NFM via differential scanning calorimetric (DSC) measurements. In-situ differential electrochemical mass spectrometry (DEMS) was further employed to analyze gas components and corresponding contents in the first two cycles of three different cathodes. As a result, the surface coating benefits from restricting the generation of major H2 components by effectively suppressing the protonation of the electrolyte solvents.By contrast, the lattice doping works for impeding the follow-up reactions of decomposed products from the initial decomposition of electrolytes.
2025, 41(2): 267-274
doi: 10.11862/CJIC.20240223
Abstract:
Bi nanoparticles were decorated on three-dimensional porous carbon (3DPC) to prepare Bi/3DPC composite, in which the 3DPC acts as a carbon framework to buffer the volume expansion of the material during discharging and charging and to enhance the electrical conductivity of the material. Besides, the micropores and mesopores of 3DPC can increase the specific surface area of the material and provide active sites for the adsorption of sodium ions. Constructing nanoscale bismuth particles cushions the structural destruction during charge and discharge processes. The impedance decreased after 50 cycles at 0.5 A·g-1, which indicates good long-term cycle stability of Bi/ 3DPC composite. And the charge storage mechanism of the materials was explored by performing cycle voltammetry tests at different scan rates, where capacitance behavior predominated. Meanwhile, Bi nanoparticles and the 3DPC take advantage of the synergistic effect, showing longterm cycle stability in sodium ion batteries. When placed under the current density of 5 A·g-1, Bi/3DPC maintained a capacity of 268.52 mAh·g-1 after 1 000 cycles.
Bi nanoparticles were decorated on three-dimensional porous carbon (3DPC) to prepare Bi/3DPC composite, in which the 3DPC acts as a carbon framework to buffer the volume expansion of the material during discharging and charging and to enhance the electrical conductivity of the material. Besides, the micropores and mesopores of 3DPC can increase the specific surface area of the material and provide active sites for the adsorption of sodium ions. Constructing nanoscale bismuth particles cushions the structural destruction during charge and discharge processes. The impedance decreased after 50 cycles at 0.5 A·g-1, which indicates good long-term cycle stability of Bi/ 3DPC composite. And the charge storage mechanism of the materials was explored by performing cycle voltammetry tests at different scan rates, where capacitance behavior predominated. Meanwhile, Bi nanoparticles and the 3DPC take advantage of the synergistic effect, showing longterm cycle stability in sodium ion batteries. When placed under the current density of 5 A·g-1, Bi/3DPC maintained a capacity of 268.52 mAh·g-1 after 1 000 cycles.
2025, 41(2): 275-283
doi: 10.11862/CJIC.20240213
Abstract:
By introducing polar functional groups such as —OH, —NH2, and —SO3H, two-dimensional truxenonebased covalent organic frameworks (TRO-COFs) with high surface area and imine bond connections are designed. The influence of polar functional groups on the CO2 capture performance of TRO COFs is explored using grand canonical Monte Carlo simulation (GCMC) and density functional theory (DFT) at 298 K and 0-1.0×105 Pa. Analysis of binding energy and cohesive energy indicate that the functional groups modified TRO-COFs still maintain high structural stability. The introduction of functional groups significantly enhances the CO2 adsorption performance, with the order as follows: TRO-COF-SO3H>TRO-COF-NH2>TRO-COF-OH>TRO-COF-H. Notably, TRO-COF-SO3H exhibits the highest CO2 adsorption capacity of 8.02 mmol·g-1 with a selectivity of CO2 over N2 and CH4 at 298 K and 1.0×105 Pa (37 and 26). Moreover, the different effects of functional groups on CO2 capture and separation are illustrated through the radial distribution function and adsorption density distribution. Finally, the modified mechanism of functional groups is elucidated from the heat of adsorption, van der Waals (vdW), and Coulomb interactions.
By introducing polar functional groups such as —OH, —NH2, and —SO3H, two-dimensional truxenonebased covalent organic frameworks (TRO-COFs) with high surface area and imine bond connections are designed. The influence of polar functional groups on the CO2 capture performance of TRO COFs is explored using grand canonical Monte Carlo simulation (GCMC) and density functional theory (DFT) at 298 K and 0-1.0×105 Pa. Analysis of binding energy and cohesive energy indicate that the functional groups modified TRO-COFs still maintain high structural stability. The introduction of functional groups significantly enhances the CO2 adsorption performance, with the order as follows: TRO-COF-SO3H>TRO-COF-NH2>TRO-COF-OH>TRO-COF-H. Notably, TRO-COF-SO3H exhibits the highest CO2 adsorption capacity of 8.02 mmol·g-1 with a selectivity of CO2 over N2 and CH4 at 298 K and 1.0×105 Pa (37 and 26). Moreover, the different effects of functional groups on CO2 capture and separation are illustrated through the radial distribution function and adsorption density distribution. Finally, the modified mechanism of functional groups is elucidated from the heat of adsorption, van der Waals (vdW), and Coulomb interactions.
2025, 41(2): 284-292
doi: 10.11862/CJIC.20240212
Abstract:
BiSbO4/BiOBr composites were synthesized using a two-step hydrothermal method and thoroughly characterized in their microscopic morphology, physical phase structure, chemical composition, optical properties, and photocatalytic performance. The study revealed that nanorod-structured BiSbO4 was successfully deposited onto the surface of flaky BiOBr, forming a heterojunction that not only extended the photoresponsive range of the catalyst but also improved the separation efficiency of photogenerated electron-hole pairs. The photocatalytic activity under simulated visible light exceeded that of individual BiSbO4 and BiOBr. With a BiSbO4 mass fraction of 6%, the composite exhibited optimal photocatalytic degradation of methylene blue (MB), achieving a degradation rate of 91.3% after 120 min of irradiation. Furthermore, the degradation rate remained at 77.4% after four cycles.
BiSbO4/BiOBr composites were synthesized using a two-step hydrothermal method and thoroughly characterized in their microscopic morphology, physical phase structure, chemical composition, optical properties, and photocatalytic performance. The study revealed that nanorod-structured BiSbO4 was successfully deposited onto the surface of flaky BiOBr, forming a heterojunction that not only extended the photoresponsive range of the catalyst but also improved the separation efficiency of photogenerated electron-hole pairs. The photocatalytic activity under simulated visible light exceeded that of individual BiSbO4 and BiOBr. With a BiSbO4 mass fraction of 6%, the composite exhibited optimal photocatalytic degradation of methylene blue (MB), achieving a degradation rate of 91.3% after 120 min of irradiation. Furthermore, the degradation rate remained at 77.4% after four cycles.
2025, 41(2): 293-307
doi: 10.11862/CJIC.20240210
Abstract:
A series of Ce, Mn-modified catalysts were prepared based on the V2O5/TiO2 catalyst matrix, and the structure and active components of the catalysts were analyzed using nitrogen adsorption-desorption, X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscope. The reaction activity was also explored. The results indicated that the prepared modified V2O5/TiO2 catalysts had good dispersion, and the Ce-Mn bimetalmodification improved the NH3 conversion rate and N2 selectivity of catalysts. When the loading amounts of Ce and Mn (the mass ratio of Ce or Mn to TiO2) were 8% and 6%, respectively, the NH3 conversion rate of the modified material reached 100% at 310 ℃, with an N2 selectivity of 78%. In-situ diffuse reflectance Fourier transform infrared spectroscopy characterization showed that NH3 adsorbed on the surface hydroxyl groups of the catalyst would preferentially participate in the reaction. As the temperature increased, NH3 adsorbed on the Brønsted and Lewis acid sites on the catalyst surface began to participate in the reaction, and at higher temperatures, the Lewis acid sites were the main sites for NH3 conversion.
A series of Ce, Mn-modified catalysts were prepared based on the V2O5/TiO2 catalyst matrix, and the structure and active components of the catalysts were analyzed using nitrogen adsorption-desorption, X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscope. The reaction activity was also explored. The results indicated that the prepared modified V2O5/TiO2 catalysts had good dispersion, and the Ce-Mn bimetalmodification improved the NH3 conversion rate and N2 selectivity of catalysts. When the loading amounts of Ce and Mn (the mass ratio of Ce or Mn to TiO2) were 8% and 6%, respectively, the NH3 conversion rate of the modified material reached 100% at 310 ℃, with an N2 selectivity of 78%. In-situ diffuse reflectance Fourier transform infrared spectroscopy characterization showed that NH3 adsorbed on the surface hydroxyl groups of the catalyst would preferentially participate in the reaction. As the temperature increased, NH3 adsorbed on the Brønsted and Lewis acid sites on the catalyst surface began to participate in the reaction, and at higher temperatures, the Lewis acid sites were the main sites for NH3 conversion.
2025, 41(2): 308-320
doi: 10.11862/CJIC.20240138
Abstract:
The effects of oleic acid (OA) and oleylamine (OLA) ligand additions on the fluorescence properties of CdSe nanocrystals were investigated, and the mechanisms of OA and OLA ligands in the growth process of CdSe nanocrystals were analyzed in depth. The optical properties, crystal structure, micro-morphology, and size distribution of CdSe nanocrystals were characterized and analyzed using various characterization methods. The results indicate that the emission peak of the CdSe nanocrystal underwent a red shift upon the addition of OA ligands, and the magnitude of the shift was directly proportional to the number of ligands added. The emission peak of CdSe nanocrystal can be adjusted within the range of 548.5-604.0 nm. When a small amount of OLA ligand was added, the peak shifted towards blue. However, with an increase in the amount of OLA ligand, the peak gradually shifted towards red, with an adjustable range of 548.0-584.4 nm. The layer-by-layer growth method, with the introduction of OA and OLA ligands, can effectively improve the bimodal emission peak phenomenon caused by multiple layer-bylayer growth. Finally, by adjusting the preparation process, four CdSe nanocrystals with fluorescence emission visualization separation were prepared with good size distribution, high photoluminescence quantum yield (PLQY) and excellent resistance to photobleaching.
The effects of oleic acid (OA) and oleylamine (OLA) ligand additions on the fluorescence properties of CdSe nanocrystals were investigated, and the mechanisms of OA and OLA ligands in the growth process of CdSe nanocrystals were analyzed in depth. The optical properties, crystal structure, micro-morphology, and size distribution of CdSe nanocrystals were characterized and analyzed using various characterization methods. The results indicate that the emission peak of the CdSe nanocrystal underwent a red shift upon the addition of OA ligands, and the magnitude of the shift was directly proportional to the number of ligands added. The emission peak of CdSe nanocrystal can be adjusted within the range of 548.5-604.0 nm. When a small amount of OLA ligand was added, the peak shifted towards blue. However, with an increase in the amount of OLA ligand, the peak gradually shifted towards red, with an adjustable range of 548.0-584.4 nm. The layer-by-layer growth method, with the introduction of OA and OLA ligands, can effectively improve the bimodal emission peak phenomenon caused by multiple layer-bylayer growth. Finally, by adjusting the preparation process, four CdSe nanocrystals with fluorescence emission visualization separation were prepared with good size distribution, high photoluminescence quantum yield (PLQY) and excellent resistance to photobleaching.
2025, 41(2): 321-328
doi: 10.11862/CJIC.20240207
Abstract:
Two tetra-iron complexes with bridging diphosphine ligands, named [Fe4(CO)10(μ-SCH2CH(CH3)S)2(dppa)] (1) and [Fe4(CO)10(μ-SCH2CH(CH3)S)2(trans-dppv)] (2), where dppa=bis(diphenylphosphino)acetylene and trans-dppv= trans-1, 2-bis(diphenylphosphino)ethylene, were prepared by the reaction of complex [Fe2(CO)6(μ-SCH2CH(CH3)S)] with dppa or trans-dppv. Both complexes were structurally identified by elemental analysis, FTIR spectra, 1H NMR, and 31P NMR, together with single-crystal X-ray diffraction analysis. X-ray crystallographic studies revealed that complex 1 consists of two di-iron propane-1, 2-dithiolate pentacarbonyl sub-units connected by a linear dppa ligand whereas a zigzag trans-dppv ligand is found in complex 2. The electrochemical properties were probed by cyclic voltammetry, showing that two irreversible reductions and one irreversible oxidation were found for both complexes. Furthermore, electrocatalytic studies were carried out by adding acetic acid as a proton source into the solution. The results demonstrated that both complexes can catalyze proton reduction to evolve hydrogen. For comparison, the catalytic efficiency of complex 2 was better than complex 1.
Two tetra-iron complexes with bridging diphosphine ligands, named [Fe4(CO)10(μ-SCH2CH(CH3)S)2(dppa)] (1) and [Fe4(CO)10(μ-SCH2CH(CH3)S)2(trans-dppv)] (2), where dppa=bis(diphenylphosphino)acetylene and trans-dppv= trans-1, 2-bis(diphenylphosphino)ethylene, were prepared by the reaction of complex [Fe2(CO)6(μ-SCH2CH(CH3)S)] with dppa or trans-dppv. Both complexes were structurally identified by elemental analysis, FTIR spectra, 1H NMR, and 31P NMR, together with single-crystal X-ray diffraction analysis. X-ray crystallographic studies revealed that complex 1 consists of two di-iron propane-1, 2-dithiolate pentacarbonyl sub-units connected by a linear dppa ligand whereas a zigzag trans-dppv ligand is found in complex 2. The electrochemical properties were probed by cyclic voltammetry, showing that two irreversible reductions and one irreversible oxidation were found for both complexes. Furthermore, electrocatalytic studies were carried out by adding acetic acid as a proton source into the solution. The results demonstrated that both complexes can catalyze proton reduction to evolve hydrogen. For comparison, the catalytic efficiency of complex 2 was better than complex 1.
2025, 41(2): 329-338
doi: 10.11862/CJIC.20240206
Abstract:
La3+-doped 0.28Pb(In1/2Nb1/2)O3-0.32Pb(Zn1/3Nb2/3)O3-0.3PbTiO3-0.1PbZrO3 (PIN-PZN-PZT) quaternary piezoelectric ceramics were prepared by the conventional solid-phase method, and the effects of La3+ doping on the microstructures and electrical performances of PIN-PZN-PZT quaternary piezoelectric ceramics were investigated. The results show that introducing La3+ can enhance the local structural heterogeneity of piezoelectric ceramics, enhancing the dielectric relaxation properties to improve the piezoelectric performance. When the La2O3 content was 1.5%, piezoelectric ceramic materials with high electrically induced strain (0.23%) and high Curie temperature (206 ℃) were obtained.
La3+-doped 0.28Pb(In1/2Nb1/2)O3-0.32Pb(Zn1/3Nb2/3)O3-0.3PbTiO3-0.1PbZrO3 (PIN-PZN-PZT) quaternary piezoelectric ceramics were prepared by the conventional solid-phase method, and the effects of La3+ doping on the microstructures and electrical performances of PIN-PZN-PZT quaternary piezoelectric ceramics were investigated. The results show that introducing La3+ can enhance the local structural heterogeneity of piezoelectric ceramics, enhancing the dielectric relaxation properties to improve the piezoelectric performance. When the La2O3 content was 1.5%, piezoelectric ceramic materials with high electrically induced strain (0.23%) and high Curie temperature (206 ℃) were obtained.
2025, 41(2): 339-348
doi: 10.11862/CJIC.20240172
Abstract:
BaTiO3 powers with different morphologies, including nanoparticles, cubes, wires, and sheets were synthesized. The morphology and phase structure of as-synthesized samples were characterized by scanning electron microscopy (SEM), X ray diffraction (XRD), Fourier transform infrared spectra (FTIR), and UV visible(UV Vis) absorption spectra. The piezocatalytic activity of BaTiO3 under different morphologies and catalytic conditions was compared, and the mechanism of differential piezocatalytic activity was explained based on finite element method simulation. The results show that the higher activity of BaTiO3 nanosheets is due to the generated higher potential. The degradation of rhodamine B (RhB) dyes by BaTiO3 nanosheets showed better catalytic activity when the solid content was 2 g·L-1, the ultrasonic frequency was 40 kHz and the dye mass concentration was 5 mg·L-1. Furthermore, the mechanism of piezocatalysis reveals that the hydroxyl radical (·OH) and superoxide radicals (·O2-) are the main reactive species in the degradation process by targeting the degradation of RhB.
BaTiO3 powers with different morphologies, including nanoparticles, cubes, wires, and sheets were synthesized. The morphology and phase structure of as-synthesized samples were characterized by scanning electron microscopy (SEM), X ray diffraction (XRD), Fourier transform infrared spectra (FTIR), and UV visible(UV Vis) absorption spectra. The piezocatalytic activity of BaTiO3 under different morphologies and catalytic conditions was compared, and the mechanism of differential piezocatalytic activity was explained based on finite element method simulation. The results show that the higher activity of BaTiO3 nanosheets is due to the generated higher potential. The degradation of rhodamine B (RhB) dyes by BaTiO3 nanosheets showed better catalytic activity when the solid content was 2 g·L-1, the ultrasonic frequency was 40 kHz and the dye mass concentration was 5 mg·L-1. Furthermore, the mechanism of piezocatalysis reveals that the hydroxyl radical (·OH) and superoxide radicals (·O2-) are the main reactive species in the degradation process by targeting the degradation of RhB.
2025, 41(2): 349-356
doi: 10.11862/CJIC.20240098
Abstract:
A broadband near-infrared Na3CrF6 phosphor was synthesized by hydrothermal method, and its structure, microstructure, and photoluminescence properties were investigated. The results show that under excitation of 435 nm, the Na3CrF6 phosphor can emit broadband near-infrared light of 650-850 nm, with a peak at 738 nm and a half maximum width of 95 nm. The crystal field intensity of Cr3+ in Na3CrF6 phosphor was calculated to be 1.72 by analyzing spectral data, indicating that Cr3+ is located in the weak crystal field environment. The luminescent intensity of Na3CrF6 phosphor decreased slowly with the increase of heating temperature in the temperature range of 298-473 K.
A broadband near-infrared Na3CrF6 phosphor was synthesized by hydrothermal method, and its structure, microstructure, and photoluminescence properties were investigated. The results show that under excitation of 435 nm, the Na3CrF6 phosphor can emit broadband near-infrared light of 650-850 nm, with a peak at 738 nm and a half maximum width of 95 nm. The crystal field intensity of Cr3+ in Na3CrF6 phosphor was calculated to be 1.72 by analyzing spectral data, indicating that Cr3+ is located in the weak crystal field environment. The luminescent intensity of Na3CrF6 phosphor decreased slowly with the increase of heating temperature in the temperature range of 298-473 K.
2025, 41(2): 357-364
doi: 10.11862/CJIC.20240096
Abstract:
Sr1-xZrSi2O7∶xDy3+ phosphors were prepared by using the high-temperature solid-state method. The crystal structure, microscopic morphology, luminescence performance, and thermal stability were studied by X-ray diffractometer, scanning electron microscope, and spectrophotometer, respectively. The results indicate that SrZrSi2O7 has a monoclinic structure and Sr2+ ions are partially occupied by Dy3+ ions. The crystal structure is not affected evidently by doping. Sr1-xZrSi2O7∶xDy3+ phosphors can be excited by near-ultraviolet light. Under 353 nm radiation, the phosphors generate blue light (493 nm) and orange-red light (581 nm) emission peaks, and they can be attributed to the electron transition from 4F9/2 to 6H15/2 and 6H13/2 energy level transitions, respectively. The quenching concentration of Dy3+ ions is 0.03 and the quenching mechanism belongs to dipole-dipole interaction. The emission intensity of Dy3+ ions was kept at 83% when the temperature increased to 150 ℃. The electronic traps and the structural rigidity of SrZrSi2O7 contribute to the excellent thermal stability of the luminescent materials.
Sr1-xZrSi2O7∶xDy3+ phosphors were prepared by using the high-temperature solid-state method. The crystal structure, microscopic morphology, luminescence performance, and thermal stability were studied by X-ray diffractometer, scanning electron microscope, and spectrophotometer, respectively. The results indicate that SrZrSi2O7 has a monoclinic structure and Sr2+ ions are partially occupied by Dy3+ ions. The crystal structure is not affected evidently by doping. Sr1-xZrSi2O7∶xDy3+ phosphors can be excited by near-ultraviolet light. Under 353 nm radiation, the phosphors generate blue light (493 nm) and orange-red light (581 nm) emission peaks, and they can be attributed to the electron transition from 4F9/2 to 6H15/2 and 6H13/2 energy level transitions, respectively. The quenching concentration of Dy3+ ions is 0.03 and the quenching mechanism belongs to dipole-dipole interaction. The emission intensity of Dy3+ ions was kept at 83% when the temperature increased to 150 ℃. The electronic traps and the structural rigidity of SrZrSi2O7 contribute to the excellent thermal stability of the luminescent materials.
2025, 41(2): 365-384
doi: 10.11862/CJIC.20240063
Abstract:
This work studied the corrosion and corrosion inhibition of nickel-cobalt bimetallic phosphide (Ni-Co-P) in aqueous solution. The results show that Ni-Co-P could react with H2O to produce H2, while Ni2+, Co2+, and PO43- ions were released into water. The nickel-to-cobalt ratio affects the reaction rate of Ni-Co-P with H2O, and increased Co content in Ni-Co-P leads to decreased corrosion rate. The influence factors, such as pH value, oxygen content, light, and temperature on the corrosion of Ni-Co-P(nNi/nCo=1/2) prepared with an initial nickel-to-cobalt ratio of 1∶2 in water were studied in detail. To inhibit the corrosion of Ni-Co-P(nNi/nCo=1/2) in aqueous solution, a strategy of coating an inert TiO2 protective layer was put forward. The TiO2 protective layer could effectively reduce the corrosion of Ni-Co-P in water and enhance its stability.
This work studied the corrosion and corrosion inhibition of nickel-cobalt bimetallic phosphide (Ni-Co-P) in aqueous solution. The results show that Ni-Co-P could react with H2O to produce H2, while Ni2+, Co2+, and PO43- ions were released into water. The nickel-to-cobalt ratio affects the reaction rate of Ni-Co-P with H2O, and increased Co content in Ni-Co-P leads to decreased corrosion rate. The influence factors, such as pH value, oxygen content, light, and temperature on the corrosion of Ni-Co-P(nNi/nCo=1/2) prepared with an initial nickel-to-cobalt ratio of 1∶2 in water were studied in detail. To inhibit the corrosion of Ni-Co-P(nNi/nCo=1/2) in aqueous solution, a strategy of coating an inert TiO2 protective layer was put forward. The TiO2 protective layer could effectively reduce the corrosion of Ni-Co-P in water and enhance its stability.
2025, 41(2): 385-394
doi: 10.11862/CJIC.20240298
Abstract:
Binary composites (ZIF-67/rGO) were synthesized by one-step precipitation method using cobalt nitrate hexahydrate as metal source, 2-methylimidazole as organic ligand, and reduced graphene oxide (rGO) as carbon carrier. Then Ru3+ was introduced for ion exchange, and the porous Ru-doped Co3O4/rGO (Ru-Co3O4/rGO) composite electrocatalyst was prepared by annealing. The phase structure, morphology, and valence state of the catalyst were analyzed by X-ray powder diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). In 1 mol·L-1 KOH, the oxygen evolution reaction (OER) performance of the catalyst was measured by linear sweep voltammetry, cyclic voltammetry, and chronoamperometry. The results show that the combination of Ru doping and rGO provides a fast channel for collaborative electron transfer. At the same time, rGO as a carbon carrier can improve the electrical conductivity of Ru-Co3O4 particles, and the uniformly dispersed nanoparticles enable the reactants to diffuse freely on the catalyst. The results showed that the electrochemical performance of Ru-Co3O4/rGO was much better than that of Co3O4/rGO, and the overpotential of Ru-Co3O4/rGO was 363.5 mV at the current density of 50 mA·cm-2.
Binary composites (ZIF-67/rGO) were synthesized by one-step precipitation method using cobalt nitrate hexahydrate as metal source, 2-methylimidazole as organic ligand, and reduced graphene oxide (rGO) as carbon carrier. Then Ru3+ was introduced for ion exchange, and the porous Ru-doped Co3O4/rGO (Ru-Co3O4/rGO) composite electrocatalyst was prepared by annealing. The phase structure, morphology, and valence state of the catalyst were analyzed by X-ray powder diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). In 1 mol·L-1 KOH, the oxygen evolution reaction (OER) performance of the catalyst was measured by linear sweep voltammetry, cyclic voltammetry, and chronoamperometry. The results show that the combination of Ru doping and rGO provides a fast channel for collaborative electron transfer. At the same time, rGO as a carbon carrier can improve the electrical conductivity of Ru-Co3O4 particles, and the uniformly dispersed nanoparticles enable the reactants to diffuse freely on the catalyst. The results showed that the electrochemical performance of Ru-Co3O4/rGO was much better than that of Co3O4/rGO, and the overpotential of Ru-Co3O4/rGO was 363.5 mV at the current density of 50 mA·cm-2.
2025, 41(2): 395-406
doi: 10.11862/CJIC.20240226
Abstract:
Five cadmium naphthalene-diphosphonates, formulated as [Cd1.5(1,4-ndpaH2)2(4,4′-bpyH)(4,4′-bpy)0.5(H2O)2]2 (1), [Cd(1,4-ndpaH2)(1,4-bib)0.5(H2O)] (2), [Cd(1,4-ndpaH3)2(1,2-dpe)(H2O)]·(1,2-dpe)·7H2O (3), (1,2-bixH)[Cd3(1,4-ndpaH)(1,4-ndpaH2)2(H2O)2] (4), and [Cd(1,4-ndpaH2)(H2O)]·H2O (5), have been synthesized from the self-assembly reactions of 1,4-naphthalenediphosphonic acid (1,4-ndpaH4) with Cd(NO3)2·4H2O by introducing auxiliary ligands with variation of rigidity, such as 4,4′-bipyridine (4,4′-bpy), 1,4-bis(1-imidazolyl)benzene (1,4-bib), 1,2-di(4-pyridyl)ethylene (1,2-dpe), 1,3-di(4-pyridyl)propane (1,3-dpp), and bis(imidazol-1-ylmethyl)benzene (1,2-bix), respectively. Structure resolution by single-crystal X-ray diffraction reveals that compound 1 possesses a layered framework, in which the {Cd3(PO2)2} trimers made up of corner-sharing two {CdO4N2} and one {CdO6} octahedra are connected by phosphonate groups, forming a ribbon, which are cross-linked by 4,4′-bipy ligands, forming a 2D layer. Compound 2 shows a 3D open-framework structure, where chains of corner-sharing {CdO4N} trigonal bipyramids and {PO3C} tetrahedra are cross-linked by 1,4-bib and/or phosphonate groups. A 1D ladder-like chain structure is found in compound 3, where the ladder-like chains made up of corner-sharing {CdO5N} octahedra and {PO3C} tetrahedra are connected by 1,4-ndpaH22-. Both compounds 4 and 5 obtained by the introduction of flexible ligands during the synthesis show a 2D layered structure, which is formed by ligand crosslinking double metal chains. Interestingly, In 4, flexible 1,2-bix was singly protonated, as guest molecules, filled between layer and layer, while flexible ligand 1,3-dpp is absent in 5. Photophysical measurements indicate that compounds 1-5 show ligand-centered emissions.
Five cadmium naphthalene-diphosphonates, formulated as [Cd1.5(1,4-ndpaH2)2(4,4′-bpyH)(4,4′-bpy)0.5(H2O)2]2 (1), [Cd(1,4-ndpaH2)(1,4-bib)0.5(H2O)] (2), [Cd(1,4-ndpaH3)2(1,2-dpe)(H2O)]·(1,2-dpe)·7H2O (3), (1,2-bixH)[Cd3(1,4-ndpaH)(1,4-ndpaH2)2(H2O)2] (4), and [Cd(1,4-ndpaH2)(H2O)]·H2O (5), have been synthesized from the self-assembly reactions of 1,4-naphthalenediphosphonic acid (1,4-ndpaH4) with Cd(NO3)2·4H2O by introducing auxiliary ligands with variation of rigidity, such as 4,4′-bipyridine (4,4′-bpy), 1,4-bis(1-imidazolyl)benzene (1,4-bib), 1,2-di(4-pyridyl)ethylene (1,2-dpe), 1,3-di(4-pyridyl)propane (1,3-dpp), and bis(imidazol-1-ylmethyl)benzene (1,2-bix), respectively. Structure resolution by single-crystal X-ray diffraction reveals that compound 1 possesses a layered framework, in which the {Cd3(PO2)2} trimers made up of corner-sharing two {CdO4N2} and one {CdO6} octahedra are connected by phosphonate groups, forming a ribbon, which are cross-linked by 4,4′-bipy ligands, forming a 2D layer. Compound 2 shows a 3D open-framework structure, where chains of corner-sharing {CdO4N} trigonal bipyramids and {PO3C} tetrahedra are cross-linked by 1,4-bib and/or phosphonate groups. A 1D ladder-like chain structure is found in compound 3, where the ladder-like chains made up of corner-sharing {CdO5N} octahedra and {PO3C} tetrahedra are connected by 1,4-ndpaH22-. Both compounds 4 and 5 obtained by the introduction of flexible ligands during the synthesis show a 2D layered structure, which is formed by ligand crosslinking double metal chains. Interestingly, In 4, flexible 1,2-bix was singly protonated, as guest molecules, filled between layer and layer, while flexible ligand 1,3-dpp is absent in 5. Photophysical measurements indicate that compounds 1-5 show ligand-centered emissions.
2025, 41(2): 407-412
doi: 10.11862/CJIC.20240214
Abstract:
A new cobalt(Ⅱ)-radical complex: [Co(im4-py)2(PNB)2] (im4-py=2-(4'-pyridyl)-4,4,5,5-tetramethylimidazole-1-oxyl, HPNB=p-nitrobenzoic acid) has been synthesized and characterized by X-ray diffraction analysis, elemental analysis, IR, and magnetic properties. X-ray diffraction analysis shows that the complex exists as mononuclear molecules and Co(Ⅱ)ion is four-coordinated with two radicals and two PNB- ligands. The magnetic susceptibility study indicates the complex exhibits weak ferromagnetic interactions between cobalt(Ⅱ) and im4-py radical. The magnetic property is explained by the magnetic and structure exchange mechanism.
A new cobalt(Ⅱ)-radical complex: [Co(im4-py)2(PNB)2] (im4-py=2-(4'-pyridyl)-4,4,5,5-tetramethylimidazole-1-oxyl, HPNB=p-nitrobenzoic acid) has been synthesized and characterized by X-ray diffraction analysis, elemental analysis, IR, and magnetic properties. X-ray diffraction analysis shows that the complex exists as mononuclear molecules and Co(Ⅱ)ion is four-coordinated with two radicals and two PNB- ligands. The magnetic susceptibility study indicates the complex exhibits weak ferromagnetic interactions between cobalt(Ⅱ) and im4-py radical. The magnetic property is explained by the magnetic and structure exchange mechanism.
2025, 41(2): 413-424
doi: 10.11862/CJIC.20240205
Abstract:
Porous spherical MnCo2S4 was synthesized by a simple solvothermal method. Thanks to the well-designed bimetallic composition and the unique porous spherical structure, the MnCo2S4 electrode exhibited an exceptional specific capacitance of 190.8 mAh·g-1 at 1 A·g-1, greatly higher than the corresponding monometallic sulfides MnS (31.7 mAh·g-1) and Co3S4 (86.7 mAh·g-1). Impressively, the as assembled MnCo2S4||porous carbon (PC) hybrid supercapacitor (HSC), showed an outstanding energy density of 76.88 Wh·kg-1 at a power density of 374.5 W·kg-1, remarkable cyclic performance with a capacity retention of 86.8% after 10 000 charge-discharge cycles at 5 A·g-1, and excellent Coulombic efficiency of 99.7%.
Porous spherical MnCo2S4 was synthesized by a simple solvothermal method. Thanks to the well-designed bimetallic composition and the unique porous spherical structure, the MnCo2S4 electrode exhibited an exceptional specific capacitance of 190.8 mAh·g-1 at 1 A·g-1, greatly higher than the corresponding monometallic sulfides MnS (31.7 mAh·g-1) and Co3S4 (86.7 mAh·g-1). Impressively, the as assembled MnCo2S4||porous carbon (PC) hybrid supercapacitor (HSC), showed an outstanding energy density of 76.88 Wh·kg-1 at a power density of 374.5 W·kg-1, remarkable cyclic performance with a capacity retention of 86.8% after 10 000 charge-discharge cycles at 5 A·g-1, and excellent Coulombic efficiency of 99.7%.
