Login In
2021 Volume 37 Issue 5
2021, 37(5): 769-777
doi: 10.11862/CJIC.2021.092
Abstract:
By incorporating two different reduced nicotinamide adenine dinucleotide (NADH) mimics within the ligand backbone, two positively charged cobalt-based metal-organic triangular hosts Co-L1 and Co-L2 (H2L1=5'-(benzo[d]thiazol-2-yl)-N'4, N'''''4″-bis((E)-pyridin-2-ylmethylene)-[1, 1': 3', 1″-terphenyl]-4, 4″-dicarbohydrazide, H2L2=5'(benzo[d]imidazol-2-yl)-N'4, N'''''4″-bis((E)-pyridin-2-ylmethylene)-[1, 1': 3', 1″-terphenyl]-4, 4″-dicar bohydrazide) have been prepared in high yield and characterized as a redox vehicle for the construction of an artificial photosynthesis (AP) system. By taking advantage of electrostatic interaction to facilitate the formation of host-guest complexes, anionic ruthenium-based photosensitizer[Ru(dcbpy)3]4- (dcbpy=2, 2'-bipyridine-4, 4'-dicarboxylic acid) was encapsulated into the suitable cavity of hosts to improve photoinduced electron transfer (PET) processes and to promote photocatalytic hydrogen production. Compared with metal-organic triangular Co-L3 without NADH mimics (H2L3=5'-methyl-N'4, N'''''4″-bis((E)-pyridin-2-ylmethylene)-[1, 1': 3', 1″-terphenyl]-4, 4″-dicarbohydrazide) and mononuclear catalyst Co-L4 (HL4=(E)-N'-(pyridin-2-ylmethylene)benzohydrazide) containing the same coordination environment and without NADH mimics, photocatalytic hydrogen production efficiency of the host-guest supramolecular photosynthetic systems could increase 1.6 and 6 times, respectively. The higher catalytic activity is attributed to the formation of host-guest complex between catalyst Co-L1 and Co-L2 and photosensitizer[Ru(dcbpy)3]4- and the introduction of NADH mimics benefiting the PET process between the catalyst and photosensitizer.
By incorporating two different reduced nicotinamide adenine dinucleotide (NADH) mimics within the ligand backbone, two positively charged cobalt-based metal-organic triangular hosts Co-L1 and Co-L2 (H2L1=5'-(benzo[d]thiazol-2-yl)-N'4, N'''''4″-bis((E)-pyridin-2-ylmethylene)-[1, 1': 3', 1″-terphenyl]-4, 4″-dicarbohydrazide, H2L2=5'(benzo[d]imidazol-2-yl)-N'4, N'''''4″-bis((E)-pyridin-2-ylmethylene)-[1, 1': 3', 1″-terphenyl]-4, 4″-dicar bohydrazide) have been prepared in high yield and characterized as a redox vehicle for the construction of an artificial photosynthesis (AP) system. By taking advantage of electrostatic interaction to facilitate the formation of host-guest complexes, anionic ruthenium-based photosensitizer[Ru(dcbpy)3]4- (dcbpy=2, 2'-bipyridine-4, 4'-dicarboxylic acid) was encapsulated into the suitable cavity of hosts to improve photoinduced electron transfer (PET) processes and to promote photocatalytic hydrogen production. Compared with metal-organic triangular Co-L3 without NADH mimics (H2L3=5'-methyl-N'4, N'''''4″-bis((E)-pyridin-2-ylmethylene)-[1, 1': 3', 1″-terphenyl]-4, 4″-dicarbohydrazide) and mononuclear catalyst Co-L4 (HL4=(E)-N'-(pyridin-2-ylmethylene)benzohydrazide) containing the same coordination environment and without NADH mimics, photocatalytic hydrogen production efficiency of the host-guest supramolecular photosynthetic systems could increase 1.6 and 6 times, respectively. The higher catalytic activity is attributed to the formation of host-guest complex between catalyst Co-L1 and Co-L2 and photosensitizer[Ru(dcbpy)3]4- and the introduction of NADH mimics benefiting the PET process between the catalyst and photosensitizer.
2021, 37(5): 778-784
doi: 10.11862/CJIC.2021.096
Abstract:
Lanthanum hydroxide (La(OH)3) was loaded on the surface of zinc-aluminum hydrotalcite (Zn-Al LDHs) by co precipitation method. The X-ray diffraction (XRD) patterns and scanning electron microscopy (SEM) images reveal that the La(OH)3 was successfully loaded on the surface of the Zn-Al LDHs, and the loaded Zn-Al LDHs still showed hexagonal plate-like crystals with uniform particle size and good dispersion; 5%La(OH)3@Zn-Al LDHs had the best electrochemical performance. Cyclic voltammetry (CV), Tafel polarization curves and electrochemical impedance spectroscope (EIS) showed that it had better reversibility, larger positive corrosion potential and lower resistance. 5%La(OH)3@Zn-Al LDHs showed the cycle retention of 94.84% after 80 cycles.
Lanthanum hydroxide (La(OH)3) was loaded on the surface of zinc-aluminum hydrotalcite (Zn-Al LDHs) by co precipitation method. The X-ray diffraction (XRD) patterns and scanning electron microscopy (SEM) images reveal that the La(OH)3 was successfully loaded on the surface of the Zn-Al LDHs, and the loaded Zn-Al LDHs still showed hexagonal plate-like crystals with uniform particle size and good dispersion; 5%La(OH)3@Zn-Al LDHs had the best electrochemical performance. Cyclic voltammetry (CV), Tafel polarization curves and electrochemical impedance spectroscope (EIS) showed that it had better reversibility, larger positive corrosion potential and lower resistance. 5%La(OH)3@Zn-Al LDHs showed the cycle retention of 94.84% after 80 cycles.
2021, 37(5): 785-790
doi: 10.11862/CJIC.2021.102
Abstract:
Three new palladium(Ⅱ) complexes with Br- as the dissociation ligand and with di-tert-butylphenyl phosphine((t-Bu)2PPh), di-tert-butyl-(4-dimethylaminophenyl)phosphine (Amphos) or 4, 5-bis(diphenyl-phosphino)-9, 9-dimethylxanthene (Xantphos) as the organic phosphine ligand, were prepared from the starting material PdBr2 via the coordination addition and ligand substitution process, with an attempt to develop more effective organophosphinopalladium catalysts for the coupling reactions. The palladium (Ⅱ) complexes were tested and characterized by elemental analysis, 1H NMR and single-crystal X-ray diffraction analysis to be trans-Pd((t-Bu)2PPh)2Br2 (1), trans-[Pd(Amphos)Br2]2 (2), cis-Pd(Xantphos)Br2 (3). Among them, trans-[Pd(Amphos)Br2]2 is a unique binuclear palladium complex in which two bromine ions act as the bridging ligand bringing two[Pd(Amphos)Br] blocks together. Two typical Suzuki organic coupling reaction models were used for evaluating the catalytic activity of three complexes along with commercially available Pd((t-Bu)2PPh)2Cl2, Pd(Amphos)2Cl2 and Pd(Xantphos)Cl2 as comparison catalysts. The results showed all three complexes displayed high catalytic activity in two selected typical Suzuki organic coupling reactions, greater than the corresponding values of Pd((t-Bu)2PPh)2Cl2, Pd(Amphos)2Cl2 and Pd(Xantphos)Cl2.
Three new palladium(Ⅱ) complexes with Br- as the dissociation ligand and with di-tert-butylphenyl phosphine((t-Bu)2PPh), di-tert-butyl-(4-dimethylaminophenyl)phosphine (Amphos) or 4, 5-bis(diphenyl-phosphino)-9, 9-dimethylxanthene (Xantphos) as the organic phosphine ligand, were prepared from the starting material PdBr2 via the coordination addition and ligand substitution process, with an attempt to develop more effective organophosphinopalladium catalysts for the coupling reactions. The palladium (Ⅱ) complexes were tested and characterized by elemental analysis, 1H NMR and single-crystal X-ray diffraction analysis to be trans-Pd((t-Bu)2PPh)2Br2 (1), trans-[Pd(Amphos)Br2]2 (2), cis-Pd(Xantphos)Br2 (3). Among them, trans-[Pd(Amphos)Br2]2 is a unique binuclear palladium complex in which two bromine ions act as the bridging ligand bringing two[Pd(Amphos)Br] blocks together. Two typical Suzuki organic coupling reaction models were used for evaluating the catalytic activity of three complexes along with commercially available Pd((t-Bu)2PPh)2Cl2, Pd(Amphos)2Cl2 and Pd(Xantphos)Cl2 as comparison catalysts. The results showed all three complexes displayed high catalytic activity in two selected typical Suzuki organic coupling reactions, greater than the corresponding values of Pd((t-Bu)2PPh)2Cl2, Pd(Amphos)2Cl2 and Pd(Xantphos)Cl2.
2021, 37(5): 791-797
doi: 10.11862/CJIC.2021.104
Abstract:
C/g-C3N4 was firstly prepared by thermal condensation method with urea and glucose as precursors, and then C/g-C3N4/MoS2 ternary composites were synthesized by solvothermal method. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), N2 adsorption-desorption, ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS), photoluminescence spectroscopy (PL) and transient photocurrent analytical tests were used to characterize the crystal structure, morphology, specific surface area and optical properties of photocatalysts. In comparison with the C/g-C3N4, the ternary composites not only present a larger specific surface area, stronger light absorption capacity, but also were more favorable for electron transfer. At the same time, the performance of visible light catalytic degradation of methyl orange was studied. It was found that C/g-C3N4/MoS2-2.0% (Mass fraction of MoS2: 2.0%) showed the highest reaction rate constant (0.008 6 min-1), which was 5.7 times and 2.3 times of g-C3N4/MoS2 2.0% (0.001 5 min-1) and C/g-C3N4 (0.003 6 min-1), respectively.
C/g-C3N4 was firstly prepared by thermal condensation method with urea and glucose as precursors, and then C/g-C3N4/MoS2 ternary composites were synthesized by solvothermal method. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), N2 adsorption-desorption, ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS), photoluminescence spectroscopy (PL) and transient photocurrent analytical tests were used to characterize the crystal structure, morphology, specific surface area and optical properties of photocatalysts. In comparison with the C/g-C3N4, the ternary composites not only present a larger specific surface area, stronger light absorption capacity, but also were more favorable for electron transfer. At the same time, the performance of visible light catalytic degradation of methyl orange was studied. It was found that C/g-C3N4/MoS2-2.0% (Mass fraction of MoS2: 2.0%) showed the highest reaction rate constant (0.008 6 min-1), which was 5.7 times and 2.3 times of g-C3N4/MoS2 2.0% (0.001 5 min-1) and C/g-C3N4 (0.003 6 min-1), respectively.
2021, 37(5): 798-808
doi: 10.11862/CJIC.2021.098
Abstract:
The lack of controllable film-forming technology limits the further application of triphenylene-based metal-organic frameworks (MOFs). In this work, the gas-liquid interface assembled Ni3(HITP)2 films (HITP3-=2, 3, 6, 7, 10, 11 hexaiminotriphenylene) with different thicknesses were transferred on the conductive glass. X-ray diffraction (XRD), field emission transmission electron microscope (FETEM), field emission scanning electron microscope (FESEM), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy were used to characterize the crystal structure, element composition and microscopic morphology of the samples. The electrochemical and electrochromic properties of Ni3(HITP)2 thin film were further studied and characterized. The results show that the Ni3(HITP)2 electrochromic film with porous structure and large specific surface area can increase the contact area with the electrolyte. Thus, the obtained film N-20 had short coloring/bleaching time (0.6/0.7 s) and high coloration efficiency (530 cm2·C-1), while N-50 had a large optical modulation range (70% at 740 nm).
The lack of controllable film-forming technology limits the further application of triphenylene-based metal-organic frameworks (MOFs). In this work, the gas-liquid interface assembled Ni3(HITP)2 films (HITP3-=2, 3, 6, 7, 10, 11 hexaiminotriphenylene) with different thicknesses were transferred on the conductive glass. X-ray diffraction (XRD), field emission transmission electron microscope (FETEM), field emission scanning electron microscope (FESEM), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy were used to characterize the crystal structure, element composition and microscopic morphology of the samples. The electrochemical and electrochromic properties of Ni3(HITP)2 thin film were further studied and characterized. The results show that the Ni3(HITP)2 electrochromic film with porous structure and large specific surface area can increase the contact area with the electrolyte. Thus, the obtained film N-20 had short coloring/bleaching time (0.6/0.7 s) and high coloration efficiency (530 cm2·C-1), while N-50 had a large optical modulation range (70% at 740 nm).
2021, 37(5): 809-816
doi: 10.11862/CJIC.2021.112
Abstract:
A simple wet-chemical method was used to synthesize Co3O4 nanoparticles (NPs) as a "tandem enzyme" (with peroxidase-like and glucose-oxidase-like activities) for unlabeled hydrogen peroxide (H2O2) and surfaceenhanced Raman scattering (SERS) for glucose. As a sensitive SERS substrate, Co3O4 NPs can catalyze the production of gluconic acid and H2O2 from glucose and O2 under the condition of pH=4.0 NaAc buffer. And then H2O2 can oxidize 3, 3', 5, 5'-tetramethylbenzidine (TMB) to form the blue oxidation product oxidized TMB (oxTMB), which showed a strong SERS signal at 1 188, 1 330, 1 610 cm-1. Therefore, we developed a new SERS strategy to analyze glucose with a detection limit of 1×10-10 mol·L-1, indicating that Co3O4 NPs have the potential for biosensors, immunoassays, and medical research.
A simple wet-chemical method was used to synthesize Co3O4 nanoparticles (NPs) as a "tandem enzyme" (with peroxidase-like and glucose-oxidase-like activities) for unlabeled hydrogen peroxide (H2O2) and surfaceenhanced Raman scattering (SERS) for glucose. As a sensitive SERS substrate, Co3O4 NPs can catalyze the production of gluconic acid and H2O2 from glucose and O2 under the condition of pH=4.0 NaAc buffer. And then H2O2 can oxidize 3, 3', 5, 5'-tetramethylbenzidine (TMB) to form the blue oxidation product oxidized TMB (oxTMB), which showed a strong SERS signal at 1 188, 1 330, 1 610 cm-1. Therefore, we developed a new SERS strategy to analyze glucose with a detection limit of 1×10-10 mol·L-1, indicating that Co3O4 NPs have the potential for biosensors, immunoassays, and medical research.
2021, 37(5): 817-823
doi: 10.11862/CJIC.2021.097
Abstract:
Ni/MCM-41 catalysts were prepared with a solvent-free method of mechanical grinding. Furtherly, Ni/MCM-41(CA) catalyst was also prepared by adding citric acid during preparation of Ni/MCM-41. Compared with Ni/MCM-41(IM) catalyst prepared with the conventional impregnation method, the physical properties of the catalyst with the solvent-free method were almost unchanged. And the dispersion of metallic nickel and the performance of naphthalene hydrogenation were slightly improved. After adding citric acid during preparation of Ni/MCM-41, the dispersion of metallic nickel in Ni/MCM-41(CA) catalyst was greatly increased from 6.9% to 67.9%, and the performance of naphthalene hydrogenation was nearly enhanced 100%. Through infrared spectroscopy, UV spectra and thermogravimetric analysis, the promotion mechanism for adding citric acid in the solvent-free method was attributed to forming a kind of nickel citrate by adding citric acid during preparation of Ni/MCM-41.
Ni/MCM-41 catalysts were prepared with a solvent-free method of mechanical grinding. Furtherly, Ni/MCM-41(CA) catalyst was also prepared by adding citric acid during preparation of Ni/MCM-41. Compared with Ni/MCM-41(IM) catalyst prepared with the conventional impregnation method, the physical properties of the catalyst with the solvent-free method were almost unchanged. And the dispersion of metallic nickel and the performance of naphthalene hydrogenation were slightly improved. After adding citric acid during preparation of Ni/MCM-41, the dispersion of metallic nickel in Ni/MCM-41(CA) catalyst was greatly increased from 6.9% to 67.9%, and the performance of naphthalene hydrogenation was nearly enhanced 100%. Through infrared spectroscopy, UV spectra and thermogravimetric analysis, the promotion mechanism for adding citric acid in the solvent-free method was attributed to forming a kind of nickel citrate by adding citric acid during preparation of Ni/MCM-41.
2021, 37(5): 824-834
doi: 10.11862/CJIC.2021.099
Abstract:
In this work, we designed a novel bipyridine ruthenium complex Ru-Indole using 3-(2-pyridine-3-vinyl)1H-indoles (Indole) as the ligand with the bipyridine ruthenium precursor Ru(bpy)2Cl2 as the coordination linkage. The structures of ligand and related complexes were characterized by using 1H NMR, ESI-MS and elemental analysis. Using a fluorescence spectrophotometer and an ultraviolet-visible spectrophotometer, it is found that the complex could emit fluorescence under the excitation of UV-Vis light, which realized the visual imaging of the complex in the cell. The introduction of the ligand greatly improved the lipophilicity of the complex Ru-Indole, rendering it to be easier to enter the cell and exhibited better anti tumor activity compared with the ligand Indole and the precursor Ru(bpy)2Cl2. Furthermore, we used flow cytometry, confocal imaging and western blotting to explore the cell death mechanism induced by Ru-Indole. The results show that the complex Ru-Indole could be enriched in the mitochondria and lysosomes of tumor cells, and could change the mitochondrial membrane potential and at last induce the autophagy.
In this work, we designed a novel bipyridine ruthenium complex Ru-Indole using 3-(2-pyridine-3-vinyl)1H-indoles (Indole) as the ligand with the bipyridine ruthenium precursor Ru(bpy)2Cl2 as the coordination linkage. The structures of ligand and related complexes were characterized by using 1H NMR, ESI-MS and elemental analysis. Using a fluorescence spectrophotometer and an ultraviolet-visible spectrophotometer, it is found that the complex could emit fluorescence under the excitation of UV-Vis light, which realized the visual imaging of the complex in the cell. The introduction of the ligand greatly improved the lipophilicity of the complex Ru-Indole, rendering it to be easier to enter the cell and exhibited better anti tumor activity compared with the ligand Indole and the precursor Ru(bpy)2Cl2. Furthermore, we used flow cytometry, confocal imaging and western blotting to explore the cell death mechanism induced by Ru-Indole. The results show that the complex Ru-Indole could be enriched in the mitochondria and lysosomes of tumor cells, and could change the mitochondrial membrane potential and at last induce the autophagy.
2021, 37(5): 835-843
doi: 10.11862/CJIC.2021.094
Abstract:
Herein, a modification method was proposed to control the morphology and particle size of materials by adding alkyl quaternary ammonium salt surfactant. In the synthesis process of LiNi0.8Co0.1Mn0.1O2 precursor, the surfactant dodecyl trimethyl bromide (DTAB) and hexadecyl trimethyl bromide (CTAB) were added; the LiNi0.8Co0.1Mn0.1O2 precursor was synthesized by using urea as compounding agent and precipitation agent and the solvent heat method as the synthesis method. Finally, hollow porous materials with ellipsoidal shape were synthesized by high temperature calcination of mixed lithium. Compared with blank samples without surfactant, the materials modified by surfactant had smaller particle size and more regular morphology. Electrochemical test showed that the initial charging capacity reached 223 and 251 mAh·g-1 respectively after adding DTAB and CTAB. Among them, the initial discharge capacity of adding CTAB reached 216 mAh·g-1 (0.1C), and the capacity retention rate was 85.1% after 100 cycles, higher than 81.7% (0.1C) of LNCM811. The modification of surfactants significantly improves the electrochemical properties of the materials and provides a new perspective for the modification of high nickel ternary anode materials.
Herein, a modification method was proposed to control the morphology and particle size of materials by adding alkyl quaternary ammonium salt surfactant. In the synthesis process of LiNi0.8Co0.1Mn0.1O2 precursor, the surfactant dodecyl trimethyl bromide (DTAB) and hexadecyl trimethyl bromide (CTAB) were added; the LiNi0.8Co0.1Mn0.1O2 precursor was synthesized by using urea as compounding agent and precipitation agent and the solvent heat method as the synthesis method. Finally, hollow porous materials with ellipsoidal shape were synthesized by high temperature calcination of mixed lithium. Compared with blank samples without surfactant, the materials modified by surfactant had smaller particle size and more regular morphology. Electrochemical test showed that the initial charging capacity reached 223 and 251 mAh·g-1 respectively after adding DTAB and CTAB. Among them, the initial discharge capacity of adding CTAB reached 216 mAh·g-1 (0.1C), and the capacity retention rate was 85.1% after 100 cycles, higher than 81.7% (0.1C) of LNCM811. The modification of surfactants significantly improves the electrochemical properties of the materials and provides a new perspective for the modification of high nickel ternary anode materials.
2021, 37(5): 844-852
doi: 10.11862/CJIC.2021.111
Abstract:
CoMoSx/CeO2-γ-Al2O3 catalyst was prepared by introducing a small amount of CeO2 by isovolume impregnation method. The morphology, reducibility, adsorption properties and reaction process of the catalysts were characterized by X-ray diffraction (XRD), high-angle annular dark field-scanning transmission electron microscopy (HAADF STEM), X-ray photoelectron spectroscopy (XPS), temperature programmed desorption/temperature programmed reduction/temperature programmed surface reaction (TPD/TPR/TPSR). And the catalytic performance and stability of the catalyst for CO reduction of SO2 were studied using a fixed bed reactor. The results show that the introduction of a small amount of CeO2 can reduce the reaction temperature. With the increase of CeO2 content, the catalytic activity of CoMoSx/CeO2-γ-Al2O3 catalyst first increased and then decreased. The catalyst with 1.5% molar fraction of CeO2 had the best catalytic activity. At the optimal reaction temperature of 350℃, SO2 was almost completely converted to S, and the catalyst had excellent stability at 300℃. The metal elements on the surface of the catalyst prepared by the isovolume impregnation method were well dispersed; the introduction of CeO2 improved the sulfidation degree and low-temperature reducibility of the catalyst, and increased the adsorption of SO2 on the catalyst surface; COS reduced the catalyst at a lower temperature, making the reaction proceed according to the synergistic mechanism of COS and oxygen vacancies.
CoMoSx/CeO2-γ-Al2O3 catalyst was prepared by introducing a small amount of CeO2 by isovolume impregnation method. The morphology, reducibility, adsorption properties and reaction process of the catalysts were characterized by X-ray diffraction (XRD), high-angle annular dark field-scanning transmission electron microscopy (HAADF STEM), X-ray photoelectron spectroscopy (XPS), temperature programmed desorption/temperature programmed reduction/temperature programmed surface reaction (TPD/TPR/TPSR). And the catalytic performance and stability of the catalyst for CO reduction of SO2 were studied using a fixed bed reactor. The results show that the introduction of a small amount of CeO2 can reduce the reaction temperature. With the increase of CeO2 content, the catalytic activity of CoMoSx/CeO2-γ-Al2O3 catalyst first increased and then decreased. The catalyst with 1.5% molar fraction of CeO2 had the best catalytic activity. At the optimal reaction temperature of 350℃, SO2 was almost completely converted to S, and the catalyst had excellent stability at 300℃. The metal elements on the surface of the catalyst prepared by the isovolume impregnation method were well dispersed; the introduction of CeO2 improved the sulfidation degree and low-temperature reducibility of the catalyst, and increased the adsorption of SO2 on the catalyst surface; COS reduced the catalyst at a lower temperature, making the reaction proceed according to the synergistic mechanism of COS and oxygen vacancies.
2021, 37(5): 853-866
doi: 10.11862/CJIC.2021.103
Abstract:
To investigate the performance of Cu-SSZ-13 for selective catalytic reduction of NO with C3H6 under lean-burn conditions, Cu-SSZ-13 with different nCu/nAl and nSi/nAl were prepared by one-step hydrothermal synthesis method using Cu2+-tetraethylenepentamine (Cu-TEPA) as a structure directing agent. The Cu-SSZ-13 catalyst with nCu/nAl=2 and n Si/nAl=6 had the best low-temperature activity, which could reach over 80% NO conversion at 200℃, and 100% NO conversion and ~100% N2 selectivity at 250~300℃. In addition, it also exhibited moderate resistance to SO2 and H2O. The influence of different nCu/nAl and nSi/nAl on the physicochemical properties of the catalysts were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), N2 adsorption-desorption test, temperature programmed reduction of H2 (H2-TPR), temperature programmed desorption of ammonia (NH3-TPD), ultraviolet -visible spectroscopy (UV-Vis) and other characterization methods. According to the results of characterizations, the excellent catalytic activity of 2.0Cu-SSZ-13(6) obtained with nCu/nAl=2 and nSi/nAl=6 may relate to the largest specific surface area, the strongest surface acidity and the highest distribution of isolated Cu2+ ions. Abundant acid sites on Cu-SSZ-13 can effectively promote the adsorption and activation of C3H6 and NO. The isolated Cu2+ ions in the 8membered rings of SSZ-13 had great redox performance, which were the main active sites for the C3H6-SCR reaction. As the nCu/nAl increased, the isolated Cu2+ ions would migrate and accumulate on the surface of the zeolite catalysts to form CuO species, resulting in the decrease in the activity of C3H6-SCR reaction.
To investigate the performance of Cu-SSZ-13 for selective catalytic reduction of NO with C3H6 under lean-burn conditions, Cu-SSZ-13 with different nCu/nAl and nSi/nAl were prepared by one-step hydrothermal synthesis method using Cu2+-tetraethylenepentamine (Cu-TEPA) as a structure directing agent. The Cu-SSZ-13 catalyst with nCu/nAl=2 and n Si/nAl=6 had the best low-temperature activity, which could reach over 80% NO conversion at 200℃, and 100% NO conversion and ~100% N2 selectivity at 250~300℃. In addition, it also exhibited moderate resistance to SO2 and H2O. The influence of different nCu/nAl and nSi/nAl on the physicochemical properties of the catalysts were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), N2 adsorption-desorption test, temperature programmed reduction of H2 (H2-TPR), temperature programmed desorption of ammonia (NH3-TPD), ultraviolet -visible spectroscopy (UV-Vis) and other characterization methods. According to the results of characterizations, the excellent catalytic activity of 2.0Cu-SSZ-13(6) obtained with nCu/nAl=2 and nSi/nAl=6 may relate to the largest specific surface area, the strongest surface acidity and the highest distribution of isolated Cu2+ ions. Abundant acid sites on Cu-SSZ-13 can effectively promote the adsorption and activation of C3H6 and NO. The isolated Cu2+ ions in the 8membered rings of SSZ-13 had great redox performance, which were the main active sites for the C3H6-SCR reaction. As the nCu/nAl increased, the isolated Cu2+ ions would migrate and accumulate on the surface of the zeolite catalysts to form CuO species, resulting in the decrease in the activity of C3H6-SCR reaction.
2021, 37(5): 867-874
doi: 10.11862/CJIC.2021.108
Abstract:
Layered double hydroxide (LDH) photogenerated electron-hole pairs are easy to recombine. Although the unique structure of nanosheets promotes the separation of carriers, the photocatalytic efficiency is still low. In this paper, taking advantage of its thin-film structure, FeNi LDH was combined with TiO2 by electrostatic self-assembly method to design and prepare efficient FeNi LDH/TiO2 composite photocatalysts, and evaluated its hydrogen production performance. Their structure, photocatalytic performance and photoelectrochemistry were characterized in detail. The results showed that the high specific surface area of FeNi LDH and the heterojunction structure of the composite were all conducive to photo-generated charge transfer. The results of photocatalytic hydrogen production showed that the hydrogen production rate (22.6 mmol·g-1·h-1) of FeNi LDH/TiO2 composite was 226 and 452 times higher than that of bare TiO2 (0.1 mmol·g-1·h-1) and FeNi LDH (0.05 mmol·g-1·h-1) respectively, indicating the crucial role of heterojunction in improving the photocatalytic efficiency of LDH.
Layered double hydroxide (LDH) photogenerated electron-hole pairs are easy to recombine. Although the unique structure of nanosheets promotes the separation of carriers, the photocatalytic efficiency is still low. In this paper, taking advantage of its thin-film structure, FeNi LDH was combined with TiO2 by electrostatic self-assembly method to design and prepare efficient FeNi LDH/TiO2 composite photocatalysts, and evaluated its hydrogen production performance. Their structure, photocatalytic performance and photoelectrochemistry were characterized in detail. The results showed that the high specific surface area of FeNi LDH and the heterojunction structure of the composite were all conducive to photo-generated charge transfer. The results of photocatalytic hydrogen production showed that the hydrogen production rate (22.6 mmol·g-1·h-1) of FeNi LDH/TiO2 composite was 226 and 452 times higher than that of bare TiO2 (0.1 mmol·g-1·h-1) and FeNi LDH (0.05 mmol·g-1·h-1) respectively, indicating the crucial role of heterojunction in improving the photocatalytic efficiency of LDH.
2021, 37(5): 875-885
doi: 10.11862/CJIC.2021.110
Abstract:
Nano-sized Li1.26Fe0.22Mn0.52O2(LFMO) cathode material coated with conducting polypyrrole (PPy) was successfully synthesized by simple chemical oxidative polymerization. The crystal structure of the sample was examined by X-ray diffraction (XRD), and the morphology and micro-structure were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The elemental mapping and Fourier transform infrared spectrometer results demonstrated that the conductive network of PPy was present in the composites and PPy was uniformly distributed on the LFMO particles. The electrochemical properties of all of the samples were investigated by galvanostatic charge-discharge test and electrochemical impedance spectroscopy (EIS) analysis, which showed that the PPy on the surface significantly decreased the charge-transfer resistance of LFMO. LFMO coated with mass ratio of 2% PPy (LFMO-2%PPy) exhibited excellent rate performance and good cycle stability. The initial discharge capacity was 206 mAh·g-1 at the 1C rate, and the initial coulombic efficiency was 87%. After 50 cycles at 1C and 2C, the capacity stabilized at 131 and 139 mAh·g-1, respectively.
Nano-sized Li1.26Fe0.22Mn0.52O2(LFMO) cathode material coated with conducting polypyrrole (PPy) was successfully synthesized by simple chemical oxidative polymerization. The crystal structure of the sample was examined by X-ray diffraction (XRD), and the morphology and micro-structure were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The elemental mapping and Fourier transform infrared spectrometer results demonstrated that the conductive network of PPy was present in the composites and PPy was uniformly distributed on the LFMO particles. The electrochemical properties of all of the samples were investigated by galvanostatic charge-discharge test and electrochemical impedance spectroscopy (EIS) analysis, which showed that the PPy on the surface significantly decreased the charge-transfer resistance of LFMO. LFMO coated with mass ratio of 2% PPy (LFMO-2%PPy) exhibited excellent rate performance and good cycle stability. The initial discharge capacity was 206 mAh·g-1 at the 1C rate, and the initial coulombic efficiency was 87%. After 50 cycles at 1C and 2C, the capacity stabilized at 131 and 139 mAh·g-1, respectively.
2021, 37(5): 886-898
doi: 10.11862/CJIC.2021.078
Abstract:
The NiCo-layered double hydroxide (LDH) was prepared directly on different carbon fiber substrates by potentiostatic deposition. This method did not need to add any binder, which can prevent the phenomenon of conductivity reduction due to the resistance of the binder. In the layered crystal structure of NiCo-LDH, the positively charged host layer and the interlayer charge compensating anion can promote ion diffusion between electrode materials, so that the active sites can be efficiently utilized. In this paper, an electrode material with a wrinkled structure was synthesized by a potentiostatic deposition technique. Benefiting from the folded lamellar structure features, this composite material (NiCo-LDH/carbon fiber cloth) had sterling specific capacitance (1 387.5 F·g-1 at 1 A·g-1). In addition, with the composite as the positive electrode and the rGO coated on the surface of nickel foam (NF) as negative material, the assembled asymmetric supercapacitor (ASC) presented superb electrochemical performance. ASC had an energy density of 26.6 Wh·kg-1 and a power density of 850.4 W·kg-1 at 1 A·g-1. The energy density remained 14.9 Wh·kg-1 as the maximum power density (8 500.3 W·kg-1).
The NiCo-layered double hydroxide (LDH) was prepared directly on different carbon fiber substrates by potentiostatic deposition. This method did not need to add any binder, which can prevent the phenomenon of conductivity reduction due to the resistance of the binder. In the layered crystal structure of NiCo-LDH, the positively charged host layer and the interlayer charge compensating anion can promote ion diffusion between electrode materials, so that the active sites can be efficiently utilized. In this paper, an electrode material with a wrinkled structure was synthesized by a potentiostatic deposition technique. Benefiting from the folded lamellar structure features, this composite material (NiCo-LDH/carbon fiber cloth) had sterling specific capacitance (1 387.5 F·g-1 at 1 A·g-1). In addition, with the composite as the positive electrode and the rGO coated on the surface of nickel foam (NF) as negative material, the assembled asymmetric supercapacitor (ASC) presented superb electrochemical performance. ASC had an energy density of 26.6 Wh·kg-1 and a power density of 850.4 W·kg-1 at 1 A·g-1. The energy density remained 14.9 Wh·kg-1 as the maximum power density (8 500.3 W·kg-1).
2021, 37(5): 899-904
doi: 10.11862/CJIC.2021.093
Abstract:
A novel symmetrical dinuclear bridging complex (NH4)2[Ru(Cym)(L)]2Cl2·4H2O (1) (Cym=p-cymene=1-isopropyl-4-methylbenzene, H2L=1, 1-dimethylbiguanide) was obtained by treatment of the precursor[Ru(Cym)Cl2]2 with metformin hydrochloride. In aqueous base solution, deprotonation of the proligand (1, 1-dimethylbiguanide) occured and the corresponding neutral ruthenium complex 1 was obtained. The structure of complex 1 has been established by FT-IR and NMR spectroscopy and single-crystal X-ray diffraction analysis. The number of crystal water was obtained by thermogravimetric analysis. The inhibition of cell proliferation activity against four human cancer cell lines (HepG-2, A549, Hela, MCF-7) of complex 1 relative to cisplatin was measured by MTT method in vitro. Notably, the novel complex displayed comparable potency toward HepG-2 (hepatocellular carcinoma, HCC) compared to cisplatin.
A novel symmetrical dinuclear bridging complex (NH4)2[Ru(Cym)(L)]2Cl2·4H2O (1) (Cym=p-cymene=1-isopropyl-4-methylbenzene, H2L=1, 1-dimethylbiguanide) was obtained by treatment of the precursor[Ru(Cym)Cl2]2 with metformin hydrochloride. In aqueous base solution, deprotonation of the proligand (1, 1-dimethylbiguanide) occured and the corresponding neutral ruthenium complex 1 was obtained. The structure of complex 1 has been established by FT-IR and NMR spectroscopy and single-crystal X-ray diffraction analysis. The number of crystal water was obtained by thermogravimetric analysis. The inhibition of cell proliferation activity against four human cancer cell lines (HepG-2, A549, Hela, MCF-7) of complex 1 relative to cisplatin was measured by MTT method in vitro. Notably, the novel complex displayed comparable potency toward HepG-2 (hepatocellular carcinoma, HCC) compared to cisplatin.
2021, 37(5): 905-913
doi: 10.11862/CJIC.2021.091
Abstract:
A series of floating photocatalysts containing BiFeO3 nanoparticles on the expanding perlite (EP) support were synthesized by hydrothermal method. The as-prepared composites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectrometer (FT-IR), scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS) and UV-Vis diffusion reflection (UV-Vis DRS). The SEM and TEM analyses indicated that BiFeO3 was dispersed on the surface of EP. The DRS spectra revealed that the composites had improved optical adsorption in the visible light region, and exhibited enhanced photocatalytic activity for methylene blue (MB) degradation under visible light irradiation. It was found that the 70%BiFeO3/EP composite showed the highest photocatalytic activity for MB dye wastewater treatment, and the first-order rate constant for 70%BiFeO3/EP was 2.2 times higher than that for pure BiFeO3. Owing to the low density of EP, the as-prepared BiFeO3/EP particles floated in water to favor phase separation and the recovery of the photocatalyst after the reaction. The recovery test shows that the composite was rather stable during the MB photodegradation.
A series of floating photocatalysts containing BiFeO3 nanoparticles on the expanding perlite (EP) support were synthesized by hydrothermal method. The as-prepared composites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectrometer (FT-IR), scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS) and UV-Vis diffusion reflection (UV-Vis DRS). The SEM and TEM analyses indicated that BiFeO3 was dispersed on the surface of EP. The DRS spectra revealed that the composites had improved optical adsorption in the visible light region, and exhibited enhanced photocatalytic activity for methylene blue (MB) degradation under visible light irradiation. It was found that the 70%BiFeO3/EP composite showed the highest photocatalytic activity for MB dye wastewater treatment, and the first-order rate constant for 70%BiFeO3/EP was 2.2 times higher than that for pure BiFeO3. Owing to the low density of EP, the as-prepared BiFeO3/EP particles floated in water to favor phase separation and the recovery of the photocatalyst after the reaction. The recovery test shows that the composite was rather stable during the MB photodegradation.
2021, 37(5): 914-920
doi: 10.11862/CJIC.2021.113
Abstract:
The rational design of 2p-4f chains, which are made of 4f ions and nitronyl nitroxide biradical, has been presented. The reaction of Ln(hfac)3·2H2O (hfac=hexafluoroacetylacetonate) and nitronyl nitroxide biradical BNPhOEt (BNPhOEt=1, 2-(bis-2, 2'-(4, 4, 5, 5-tetramethylimidazolyl-1-oxyl-3-oxide) phenoxy)ethane) afforded two isostructural chains of the formula[Ln(hfac)3(BNPhOEt)]·C6H14 (Ln=Tb (1), Ho (2)). Direct-current magnetic susceptibility studies show ferromagnetic 4f-radical interaction in Tb complex while antiferromagnetic interaction in Ho derivative. In addition, the luminescence emission spectra of two complexes vary depending on lanthanide ion.
The rational design of 2p-4f chains, which are made of 4f ions and nitronyl nitroxide biradical, has been presented. The reaction of Ln(hfac)3·2H2O (hfac=hexafluoroacetylacetonate) and nitronyl nitroxide biradical BNPhOEt (BNPhOEt=1, 2-(bis-2, 2'-(4, 4, 5, 5-tetramethylimidazolyl-1-oxyl-3-oxide) phenoxy)ethane) afforded two isostructural chains of the formula[Ln(hfac)3(BNPhOEt)]·C6H14 (Ln=Tb (1), Ho (2)). Direct-current magnetic susceptibility studies show ferromagnetic 4f-radical interaction in Tb complex while antiferromagnetic interaction in Ho derivative. In addition, the luminescence emission spectra of two complexes vary depending on lanthanide ion.
2021, 37(5): 921-928
doi: 10.11862/CJIC.2021.101
Abstract:
Three complexes, namely {[Zn(H2L) (H2O)3]·H2O·0.5H4L}n (1), {[Co(L)0.5(4, 4'-bpy)]·0.5H2O}n (2) and {[Co(L)0.5(pbmb)(H2O)]·H2O}n (3) (H4L=5, 5'-(hexane-1, 6-diyl)-bis(oxy)diisophthalic acid, 4, 4'-bpy=4, 4'-bipyridine, pbmb=1, 1'-(1, 3-propane)bis-(2-methylbenzimidazole)), have been prepared by solvo-/hydrothermal reactions. Complex 1 belongs to a 1D chain structure. Complex 2 presents a 3D 3-fold interpenetrating framework with the Schläfli symbol (64·7·8)(6·72). Complex 3 features a (3, 4)-connected 2D network with the Schläfli symbol (4·62) (42·62·82). Complex 1 exhibited better fluorescence properties. CCDC: 1968748, 1; 1968750, 2; 1968751, 3.
Three complexes, namely {[Zn(H2L) (H2O)3]·H2O·0.5H4L}n (1), {[Co(L)0.5(4, 4'-bpy)]·0.5H2O}n (2) and {[Co(L)0.5(pbmb)(H2O)]·H2O}n (3) (H4L=5, 5'-(hexane-1, 6-diyl)-bis(oxy)diisophthalic acid, 4, 4'-bpy=4, 4'-bipyridine, pbmb=1, 1'-(1, 3-propane)bis-(2-methylbenzimidazole)), have been prepared by solvo-/hydrothermal reactions. Complex 1 belongs to a 1D chain structure. Complex 2 presents a 3D 3-fold interpenetrating framework with the Schläfli symbol (64·7·8)(6·72). Complex 3 features a (3, 4)-connected 2D network with the Schläfli symbol (4·62) (42·62·82). Complex 1 exhibited better fluorescence properties. CCDC: 1968748, 1; 1968750, 2; 1968751, 3.
2021, 37(5): 929-936
doi: 10.11862/CJIC.2021.076
Abstract:
In this paper, the effect of mass ratio of Ni and Co (wNi: wCo) in initial solution on the structure and properties of Ni-Co-S-O composite catalysts was studied. A three-dimensional petal-like and hierarchically connected nano-structured Ni-Co-S-O composite catalyst was obtained on a nickel foam (NF) substrate by a hydrothermal method. When w Ni: wCo=1:2, the prepared Ni-Co-S-O/NF(1:2) catalyst has a larger electrochemically active area (ECSA) and the best oxygen evolution reaction (OER) catalytic performance in alkaline water electrolysis. In 1 mol·L-1 KOH alkaline solution, Ni-Co-S-O/NF(1:2) only need 61 and 313 mV to achieve the current density of 10 and 100 mA·cm-2 respectively. At the same time, its Tafel slope was 155 mV·dec-1. After tested at a high current density of 100 mA·cm-2 for 24 h in the alkaline solution, the Ni-Co-S-O/NF(1:2) could still maintain sheet structure and displayed a good durability.
In this paper, the effect of mass ratio of Ni and Co (wNi: wCo) in initial solution on the structure and properties of Ni-Co-S-O composite catalysts was studied. A three-dimensional petal-like and hierarchically connected nano-structured Ni-Co-S-O composite catalyst was obtained on a nickel foam (NF) substrate by a hydrothermal method. When w Ni: wCo=1:2, the prepared Ni-Co-S-O/NF(1:2) catalyst has a larger electrochemically active area (ECSA) and the best oxygen evolution reaction (OER) catalytic performance in alkaline water electrolysis. In 1 mol·L-1 KOH alkaline solution, Ni-Co-S-O/NF(1:2) only need 61 and 313 mV to achieve the current density of 10 and 100 mA·cm-2 respectively. At the same time, its Tafel slope was 155 mV·dec-1. After tested at a high current density of 100 mA·cm-2 for 24 h in the alkaline solution, the Ni-Co-S-O/NF(1:2) could still maintain sheet structure and displayed a good durability.
2021, 37(5): 937-944
doi: 10.11862/CJIC.2021.100
Abstract:
The reactions of 1, 2, 4, 5-benzenetetracarboxylic acid (H4BTEC) with the transition metal ions in the presence of neutral viologen moiety, 1-carboxyethyl-4, 4'-bipyridine (CEbpy), led to three isostructural co-crystals[M(H2O)5(BTEC)0.5]·(CEbpy) (M=Mn (1), Zn (2), Co (3)) in an alkaline environment. Upon UV irradiation, these three compounds exhibited obvious photochromic behaviors owing to the formation of viologen radicals through photo-induced electron transfer. Meanwhile, compound 3 exhibited irreversible hydrochromic behavior upon heating, while compounds 1 and 2 did not. The influence of metal ions on their chromic behaviors has been discussed. CCDC: 1953749, 1; 1954911, 2; 2032783, 3.
The reactions of 1, 2, 4, 5-benzenetetracarboxylic acid (H4BTEC) with the transition metal ions in the presence of neutral viologen moiety, 1-carboxyethyl-4, 4'-bipyridine (CEbpy), led to three isostructural co-crystals[M(H2O)5(BTEC)0.5]·(CEbpy) (M=Mn (1), Zn (2), Co (3)) in an alkaline environment. Upon UV irradiation, these three compounds exhibited obvious photochromic behaviors owing to the formation of viologen radicals through photo-induced electron transfer. Meanwhile, compound 3 exhibited irreversible hydrochromic behavior upon heating, while compounds 1 and 2 did not. The influence of metal ions on their chromic behaviors has been discussed. CCDC: 1953749, 1; 1954911, 2; 2032783, 3.
2021, 37(5): 945-952
doi: 10.11862/CJIC.2021.079
Abstract:
Two metal-organic frameworks (MOFs), [Ni(μ2-H2O)(L)(DMF)(H2O)]·0.5H2O (1) and[Cd2.5(L)(trz)3(H2O)2]·2.5DMF (2) (L=2, 2'-dimethyl-4, 4'-biphenyldicarboxylic acid, DMF=N, N-dimethylformamide, Htrz=1, 2, 4-triazole), have been synthesized and characterized by FT-IR, thermogravimetric analysis (TGA), powder and single crystal X-ray diffraction. MOF 1 crystallizes in monoclinic system with a space group P21/c. Ni(Ⅱ) ion adopts an elongated[NiO6] octahedron as a 4-connected node and is linked by μ2-H2O and L2- ligands to generate a 2D sql topological network. MOF 2 crystallizes in monoclinic system with a space group C2/m and contains three crystallographically different Cd(Ⅱ) ions. Each Cd(Ⅱ) ion shows a distorted octahedral geometry and three Cd(Ⅱ) ions are connected by trz- co-ligands in a μ1, 2, 4-bridging mode to form a 2D kgd layer with (3, 6) topology in the ab plane. These layers are further pillared by the L2- ligands along the c axis to produce a binodal (4, 8)-connected 3D flu framework. The TGA showed that 1 and 2 were stable below 390 and 230℃, respectively. CCDC: 2042076, 1; 2042077, 2.
Two metal-organic frameworks (MOFs), [Ni(μ2-H2O)(L)(DMF)(H2O)]·0.5H2O (1) and[Cd2.5(L)(trz)3(H2O)2]·2.5DMF (2) (L=2, 2'-dimethyl-4, 4'-biphenyldicarboxylic acid, DMF=N, N-dimethylformamide, Htrz=1, 2, 4-triazole), have been synthesized and characterized by FT-IR, thermogravimetric analysis (TGA), powder and single crystal X-ray diffraction. MOF 1 crystallizes in monoclinic system with a space group P21/c. Ni(Ⅱ) ion adopts an elongated[NiO6] octahedron as a 4-connected node and is linked by μ2-H2O and L2- ligands to generate a 2D sql topological network. MOF 2 crystallizes in monoclinic system with a space group C2/m and contains three crystallographically different Cd(Ⅱ) ions. Each Cd(Ⅱ) ion shows a distorted octahedral geometry and three Cd(Ⅱ) ions are connected by trz- co-ligands in a μ1, 2, 4-bridging mode to form a 2D kgd layer with (3, 6) topology in the ab plane. These layers are further pillared by the L2- ligands along the c axis to produce a binodal (4, 8)-connected 3D flu framework. The TGA showed that 1 and 2 were stable below 390 and 230℃, respectively. CCDC: 2042076, 1; 2042077, 2.
2021, 37(5): 953-960
doi: 10.11862/CJIC.2021.106
Abstract:
By virtue of 2, 6-bis(4-carboxybenzylidene)cyclohexanone (H2L) as the ligand, metal-organic framework [MnL]n has been successfully fabricated. This compound has been characterized by FT-IR, powder X-ray diffraction, cyclic voltammogram, solid UV, X-ray photoelectron spectroscopy and single-crystal X-ray diffraction. It crystalizes in triclinic system with space group P1, and the asymmetric unit is composed of one Mn(Ⅱ) ion and one ligand. The carboxyl groups at both ends of the ligand are monodentate coordination, and the oxygen on the carbonyl group in the middle of the ligand coordinate with the central ion as well. Each ligand is coordinated with three Mn(Ⅱ) ions and consequently, achieving a relatively stable triangular coordination configuration. The Mn (Ⅱ) ion forms a six-coordinated configuration with oxygen atoms from six different ligands, i. e., those four O atoms in the equatorial plane derived from four different ligands' carboxyl groups, the other two O atoms on the two vertices from the different ligands' carbonyl groups, respectively. As a consequence, the octahedral configuration[MnO6] unit is formed. Based on the topological analysis, its two-dimensional (2D) kgd structural character could be observed. The cyclic voltammogram showed that the half-wave potential, E1/2=(Ecp+Eap)/2, was 171 mV when the sweep speed was 30 mV·s-1. The solid UV absorption spectra showed the band gap was ~1.76 eV. Photocatalytic activity has been observed in the process of degrading of dye molecules such as methylene blue and methyl orange. CCDC: 2045728.
By virtue of 2, 6-bis(4-carboxybenzylidene)cyclohexanone (H2L) as the ligand, metal-organic framework [MnL]n has been successfully fabricated. This compound has been characterized by FT-IR, powder X-ray diffraction, cyclic voltammogram, solid UV, X-ray photoelectron spectroscopy and single-crystal X-ray diffraction. It crystalizes in triclinic system with space group P1, and the asymmetric unit is composed of one Mn(Ⅱ) ion and one ligand. The carboxyl groups at both ends of the ligand are monodentate coordination, and the oxygen on the carbonyl group in the middle of the ligand coordinate with the central ion as well. Each ligand is coordinated with three Mn(Ⅱ) ions and consequently, achieving a relatively stable triangular coordination configuration. The Mn (Ⅱ) ion forms a six-coordinated configuration with oxygen atoms from six different ligands, i. e., those four O atoms in the equatorial plane derived from four different ligands' carboxyl groups, the other two O atoms on the two vertices from the different ligands' carbonyl groups, respectively. As a consequence, the octahedral configuration[MnO6] unit is formed. Based on the topological analysis, its two-dimensional (2D) kgd structural character could be observed. The cyclic voltammogram showed that the half-wave potential, E1/2=(Ecp+Eap)/2, was 171 mV when the sweep speed was 30 mV·s-1. The solid UV absorption spectra showed the band gap was ~1.76 eV. Photocatalytic activity has been observed in the process of degrading of dye molecules such as methylene blue and methyl orange. CCDC: 2045728.
