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2023 Volume 39 Issue 10
2023, 39(10): 1841-1847
doi: 10.11862/CJIC.2023.163
Abstract:
In the semiconductor industry, efficient capture of isopentane from tetramethylsilane (TMS)/isopentane mixtures is very important. Herein, we chose MOF-801 with cages to achieve the separation of isopentane from TMS by using the difference in their adsorption capacity for TMS and isopentane. The gas adsorption test results showed that the isopentane uptake amount of MOF-801 was 2.56 mmol·g-1 and the TMS was 1.20 mmol·g-1 at 298 K and 60 kPa. Ideal adsorption solution theory (IAST) calculations showed that its separation selectivity for the TMS/isopentane (95:5, volume ratio) mixture was 105.8. The great separation performance of MOF-801 was further verified by the liquid-phase adsorption separation experiments, and the purity of the obtained TMS was greater than 99.98% (volume fraction).
In the semiconductor industry, efficient capture of isopentane from tetramethylsilane (TMS)/isopentane mixtures is very important. Herein, we chose MOF-801 with cages to achieve the separation of isopentane from TMS by using the difference in their adsorption capacity for TMS and isopentane. The gas adsorption test results showed that the isopentane uptake amount of MOF-801 was 2.56 mmol·g-1 and the TMS was 1.20 mmol·g-1 at 298 K and 60 kPa. Ideal adsorption solution theory (IAST) calculations showed that its separation selectivity for the TMS/isopentane (95:5, volume ratio) mixture was 105.8. The great separation performance of MOF-801 was further verified by the liquid-phase adsorption separation experiments, and the purity of the obtained TMS was greater than 99.98% (volume fraction).
2023, 39(10): 1848-1856
doi: 10.11862/CJIC.2023.155
Abstract:
Molybdenum disulfide nanosheets (MoS2) are affected by charged impurities, structural defects and traps, and their easy aggregation leads to the deterioration of their electron transfer performance, which limits their application. In this study, Ag NPs/MoS2 composites were prepared by combining a few layers of MoS2 nanosheets with silver nanoparticles (Ag NPs), in order to improve the electrochemical performance of MoS2 nanosheets. Firstly, the low-layer MoS2 nanosheets were prepared by ultrasonic assisted liquid phase stripping method, and then the Ag NPs/MoS2 composites were prepared by microwave reduction method. After Ag NPs/MoS2 composites were modified onto screen printed electrodes (SPE), the peak current of cyclic voltammetry (CV) curve was 1.8 times of that of MoS2 modified SPE, and the peak current of square wave voltammetry (SWV) curve was 3.4 times of that of MoS2 modified SPE. The electron transfer impedance (Ret) of electrochemical impedance spectroscopy (EIS) was only 167 Ω, which was significantly lower than that of MoS2/SPE (320 Ω), indicating that compared to that of MoS2 nanosheets, the electrochemical performance of Ag NPs/MoS2 composites is significantly enhanced. Subsequently, the conductive mechanism of the highly conductive Ag NPs/MoS2 composites was also speculated. Finally, an electrochemical sensor was constructed based on Ag NPs/MoS2 composites and used for the detection of prostate specific antigen (PSA). The results showed that the detection limit of the sensor for PSA was 0.009 ng·mL-1, the linear detection range was 0.1~1 000 ng·mL-1, and the sensitivity was 0.011 μA·mL·ng-1.
Molybdenum disulfide nanosheets (MoS2) are affected by charged impurities, structural defects and traps, and their easy aggregation leads to the deterioration of their electron transfer performance, which limits their application. In this study, Ag NPs/MoS2 composites were prepared by combining a few layers of MoS2 nanosheets with silver nanoparticles (Ag NPs), in order to improve the electrochemical performance of MoS2 nanosheets. Firstly, the low-layer MoS2 nanosheets were prepared by ultrasonic assisted liquid phase stripping method, and then the Ag NPs/MoS2 composites were prepared by microwave reduction method. After Ag NPs/MoS2 composites were modified onto screen printed electrodes (SPE), the peak current of cyclic voltammetry (CV) curve was 1.8 times of that of MoS2 modified SPE, and the peak current of square wave voltammetry (SWV) curve was 3.4 times of that of MoS2 modified SPE. The electron transfer impedance (Ret) of electrochemical impedance spectroscopy (EIS) was only 167 Ω, which was significantly lower than that of MoS2/SPE (320 Ω), indicating that compared to that of MoS2 nanosheets, the electrochemical performance of Ag NPs/MoS2 composites is significantly enhanced. Subsequently, the conductive mechanism of the highly conductive Ag NPs/MoS2 composites was also speculated. Finally, an electrochemical sensor was constructed based on Ag NPs/MoS2 composites and used for the detection of prostate specific antigen (PSA). The results showed that the detection limit of the sensor for PSA was 0.009 ng·mL-1, the linear detection range was 0.1~1 000 ng·mL-1, and the sensitivity was 0.011 μA·mL·ng-1.
2023, 39(10): 1857-1868
doi: 10.11862/CJIC.2023.164
Abstract:
Aiming at enhancing the degradation efficiency of antibiotics in slightly polluted water bodies, the photocatalytic synergistic sodium peroxysulfate (PDS)-activated catalytic oxidation using chiral mesoporous TiO2 under irradiation of visible light (PDS/vis-TiO2) was employed to degrade tetracycline (TC). The differences in active species and degradation pathways of PDS activation (PDS/TiO2), visible light photocatalysis (vis-TiO2), and PDS/vis-TiO2 systems using mesoporous TiO2 as catalysts for TC degradation were comparatively studied. The results showed that the asymmetric helical stacking structure introduced abundant Ti3+ into chiral mesoporous TiO2, not only improving its visible light response but also activating PDS by Ti3+/Ti4+ couples to form free radicals. Both the photogenerated holes h+ and the free radicals (like ·OH) in the PDS/vis-TiO2 system could simultaneously participate in TC degradation. Within 5 h, the removal rate of TC (the concentration of TC in the solution was 5 mg·L-1) using the PDS/vis-TiO2 system could reach over 95%, far exceeding that of the PDS/TiO2 system (with a TC removal rate of 48.9%) and the vis-TiO2 system (with a TC removal rate of 71.1%). PDS/vis-TiO2 system had a high removal rate of TC in solutions with different concentrations, and the degradation all followed a first-order kinetic reaction process. Even when the initial concentration of TC reached 15 mg·L-1, the 5 h removal rate of TC by PDS/vis-TiO2 system could still reach 67.2%, which further indicated that the PDS synergistic photocatalysis had an effective ability to degrade TC. However, the removal rate of TC at low concentrations by PDS/vis-TiO2 was faster than using the same amount of TiO2 catalyst and PDS. Added PDS in the photocatalytic system would be activated by the photo-generated electrons to generate free radicals, which then consume photo-generated electrons to improve the separation rate of photo-generated holes and electrons, thus achieving synergistic enhancement on the pollutant degradation. Additionally, the free radicals after PDS activation would also enhance TC degradation. The density functional theory calculation and intermediate product analysis results indicate that the degradation pathway of TC in the PDS/vis-TiO2 system includes the degradation pathway of attacking TC by h+, as well as the degradation pathway of TC after the free radicals attack.
Aiming at enhancing the degradation efficiency of antibiotics in slightly polluted water bodies, the photocatalytic synergistic sodium peroxysulfate (PDS)-activated catalytic oxidation using chiral mesoporous TiO2 under irradiation of visible light (PDS/vis-TiO2) was employed to degrade tetracycline (TC). The differences in active species and degradation pathways of PDS activation (PDS/TiO2), visible light photocatalysis (vis-TiO2), and PDS/vis-TiO2 systems using mesoporous TiO2 as catalysts for TC degradation were comparatively studied. The results showed that the asymmetric helical stacking structure introduced abundant Ti3+ into chiral mesoporous TiO2, not only improving its visible light response but also activating PDS by Ti3+/Ti4+ couples to form free radicals. Both the photogenerated holes h+ and the free radicals (like ·OH) in the PDS/vis-TiO2 system could simultaneously participate in TC degradation. Within 5 h, the removal rate of TC (the concentration of TC in the solution was 5 mg·L-1) using the PDS/vis-TiO2 system could reach over 95%, far exceeding that of the PDS/TiO2 system (with a TC removal rate of 48.9%) and the vis-TiO2 system (with a TC removal rate of 71.1%). PDS/vis-TiO2 system had a high removal rate of TC in solutions with different concentrations, and the degradation all followed a first-order kinetic reaction process. Even when the initial concentration of TC reached 15 mg·L-1, the 5 h removal rate of TC by PDS/vis-TiO2 system could still reach 67.2%, which further indicated that the PDS synergistic photocatalysis had an effective ability to degrade TC. However, the removal rate of TC at low concentrations by PDS/vis-TiO2 was faster than using the same amount of TiO2 catalyst and PDS. Added PDS in the photocatalytic system would be activated by the photo-generated electrons to generate free radicals, which then consume photo-generated electrons to improve the separation rate of photo-generated holes and electrons, thus achieving synergistic enhancement on the pollutant degradation. Additionally, the free radicals after PDS activation would also enhance TC degradation. The density functional theory calculation and intermediate product analysis results indicate that the degradation pathway of TC in the PDS/vis-TiO2 system includes the degradation pathway of attacking TC by h+, as well as the degradation pathway of TC after the free radicals attack.
2023, 39(10): 1869-1876
doi: 10.11862/CJIC.2023.156
Abstract:
Three charge-transfer (CT) complexes (1+·)(I3)·I2, (2+·)(I5)·I2, and (32+)(I3)2 have been prepared via solvent evaporation method comprising arylthio - substituted tetrathiafulvalene derivatives (Ar-S-TTF) and iodine. Single crystal X-ray diffraction, UV-Vis spectrum, and cyclic voltammetry were used to characterize the complexes. Complex (1+·)(I3)·I2 crystallizes in the C2/c space group. 1+· takes the chair configuration. The asymmetric unit contains half of 1+· ions, half of I3- ions, and half of I2 molecules. The charge transfer between compound 1 with iodine is consistent in the complex in solution. Complex (2+·)(I5)·I2 crystallizes in the P1 space group, and 2+· takes the chair conformation. The asymmetric unit contains one 2+· ion, one I5- ion, and one I2 molecule. Complex (32+)(I3)2 crystallizes in the Pbca space group, and 32+ takes the unique planar configuration. The asymmetric unit contains one 32+ ion and two I3- ions. Compounds 2 and 3 exhibit different charge transfers with iodine in solution and the complex. The iodine components in the complexes show various structures including the 1D chain of I3- or I5-/I2, and 2D iodine networks comprised of I2 and I3-.
Three charge-transfer (CT) complexes (1+·)(I3)·I2, (2+·)(I5)·I2, and (32+)(I3)2 have been prepared via solvent evaporation method comprising arylthio - substituted tetrathiafulvalene derivatives (Ar-S-TTF) and iodine. Single crystal X-ray diffraction, UV-Vis spectrum, and cyclic voltammetry were used to characterize the complexes. Complex (1+·)(I3)·I2 crystallizes in the C2/c space group. 1+· takes the chair configuration. The asymmetric unit contains half of 1+· ions, half of I3- ions, and half of I2 molecules. The charge transfer between compound 1 with iodine is consistent in the complex in solution. Complex (2+·)(I5)·I2 crystallizes in the P1 space group, and 2+· takes the chair conformation. The asymmetric unit contains one 2+· ion, one I5- ion, and one I2 molecule. Complex (32+)(I3)2 crystallizes in the Pbca space group, and 32+ takes the unique planar configuration. The asymmetric unit contains one 32+ ion and two I3- ions. Compounds 2 and 3 exhibit different charge transfers with iodine in solution and the complex. The iodine components in the complexes show various structures including the 1D chain of I3- or I5-/I2, and 2D iodine networks comprised of I2 and I3-.
2023, 39(10): 1877-1886
doi: 10.11862/CJIC.2023.153
Abstract:
CuW/CeTi and W/CuCeTi catalysts were prepared by impregnation method. The effects of different action modes of Cu on denitrification performance of NH3 selective catalytic reduction of NOx (NH3-SCR) reaction were investigated. Studies showed that fresh CuW/CeTi and W/CuCeTi exhibited excellent activity at low temperature. After 800 ℃ and 10 h hydrothermal aging, W/CuCeTi showed better denitration performance than CuW/CeTi, which proves that W/CuCeTi has higher hydrothermal stability. Then, these catalysts were characterized by transmission electron microscope (TEM), X - ray diffraction (XRD), Raman spectrum (Raman), N2 physical adsorption - desorption, X-ray photoelectron spectroscopy (XPS), ammonia temperature-programmed desorption (NH3-TPD) and hydrogen temperature-programmed reduction (H2-TPR). It was found that the Cu-O-Ce structure formed by Cu doping can improve the anti-sintering ability of CeTi, weaken the interaction of W-CeO2, and thus inhibits the formation of Ce2(WO4)3 in the aging process. Therefore, W/CuCeTi shows better hydrothermal stability.
CuW/CeTi and W/CuCeTi catalysts were prepared by impregnation method. The effects of different action modes of Cu on denitrification performance of NH3 selective catalytic reduction of NOx (NH3-SCR) reaction were investigated. Studies showed that fresh CuW/CeTi and W/CuCeTi exhibited excellent activity at low temperature. After 800 ℃ and 10 h hydrothermal aging, W/CuCeTi showed better denitration performance than CuW/CeTi, which proves that W/CuCeTi has higher hydrothermal stability. Then, these catalysts were characterized by transmission electron microscope (TEM), X - ray diffraction (XRD), Raman spectrum (Raman), N2 physical adsorption - desorption, X-ray photoelectron spectroscopy (XPS), ammonia temperature-programmed desorption (NH3-TPD) and hydrogen temperature-programmed reduction (H2-TPR). It was found that the Cu-O-Ce structure formed by Cu doping can improve the anti-sintering ability of CeTi, weaken the interaction of W-CeO2, and thus inhibits the formation of Ce2(WO4)3 in the aging process. Therefore, W/CuCeTi shows better hydrothermal stability.
2023, 39(10): 1887-1897
doi: 10.11862/CJIC.2023.160
Abstract:
Here, we describe [Os(η6-bip)(1, 3-bib)Cl]2Cl2 (bib-Os) (η6-bip=η6-biphenyl, 1, 3-bib=1, 3-di(1H-imidazol-1-yl) benzene), a binuclear Os(Ⅱ) complex, which was characterized by 1H NMR and ESI-MS. The results showed that complex bib-Os had good lipophilicity (lg Po/w=1.52) and was easy to accumulate in cells. Complex bib-Os showed high antiproliferative activity against human ovarian A2780 cancer cells (IC50=4.2 μmol·L-1), producing a large number of reactive oxygen species (ROS) and inducing mitochondrial morphological damage and membrane potential decline. Lipid peroxide (LPO) accumulation, glutathione (GSH) depletion, and glutathione peroxidase 4 (GPX4) inhibition further verified bib-Os-induced cell death through the ferroptosis pathway.
Here, we describe [Os(η6-bip)(1, 3-bib)Cl]2Cl2 (bib-Os) (η6-bip=η6-biphenyl, 1, 3-bib=1, 3-di(1H-imidazol-1-yl) benzene), a binuclear Os(Ⅱ) complex, which was characterized by 1H NMR and ESI-MS. The results showed that complex bib-Os had good lipophilicity (lg Po/w=1.52) and was easy to accumulate in cells. Complex bib-Os showed high antiproliferative activity against human ovarian A2780 cancer cells (IC50=4.2 μmol·L-1), producing a large number of reactive oxygen species (ROS) and inducing mitochondrial morphological damage and membrane potential decline. Lipid peroxide (LPO) accumulation, glutathione (GSH) depletion, and glutathione peroxidase 4 (GPX4) inhibition further verified bib-Os-induced cell death through the ferroptosis pathway.
2023, 39(10): 1898-1904
doi: 10.11862/CJIC.2023.165
Abstract:
La3+ doped CaCaFe2O4 materials have been synthesized by the electrospinning method. The structure and morphology of obtained samples were characterized by X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. Subsequently, the influence of the doping amount (mass fraction) of La3+ on the gas-sensing properties of CaFe2O4 was investigated. The results indicated that 3% La3+ doped CaCaFe2O4 materials exhibited the highest response value (Ra/Rg=14.1) to 100 μL·L-1 formaldehyde at room temperature. More importantly, the detection limit was as low as 0.1 nL·L-1, and the response/ recovery time only was 4.3 s/8.4 s.
La3+ doped CaCaFe2O4 materials have been synthesized by the electrospinning method. The structure and morphology of obtained samples were characterized by X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. Subsequently, the influence of the doping amount (mass fraction) of La3+ on the gas-sensing properties of CaFe2O4 was investigated. The results indicated that 3% La3+ doped CaCaFe2O4 materials exhibited the highest response value (Ra/Rg=14.1) to 100 μL·L-1 formaldehyde at room temperature. More importantly, the detection limit was as low as 0.1 nL·L-1, and the response/ recovery time only was 4.3 s/8.4 s.
2023, 39(10): 1905-1913
doi: 10.11862/CJIC.2023.150
Abstract:
Ru/NiFe LDH was obtained by introducing Ru into the surface of NiFe layered double hydroxide (LDH) nanosheet arrays by using the ion-exchange method. The introduction of Ru species promotes electrocatalytic performances of NiFe LDH toward water splitting with the assistance of the increased active surface areas with much more active sites, as well as optimal electronic structure. Ru anchored NiFe LDH (Ru/NiFe LDH) showed superior activity toward hydrogen evolution reaction with an overpotential of 50 mV to reach 10 mA·cm-2 with Tafel slop of 52.3 mV·dec-1, compared with that of NiFe LDH with 226 mV at 10 mA·cm-2 and Tafel slope of 157.5 mV·dec-1. In addition, Ru/NiFe LDH catalyst also exhibited excellent performance toward oxygen evolution reaction, requiring an overpotential of 231 mV to achieve 50 mA·cm-2, outperforming that of NiFe LDH (237 mV). As expected, Ru/NiFe LDH catalyst showed robust tolerance to long-term working catalysis.
Ru/NiFe LDH was obtained by introducing Ru into the surface of NiFe layered double hydroxide (LDH) nanosheet arrays by using the ion-exchange method. The introduction of Ru species promotes electrocatalytic performances of NiFe LDH toward water splitting with the assistance of the increased active surface areas with much more active sites, as well as optimal electronic structure. Ru anchored NiFe LDH (Ru/NiFe LDH) showed superior activity toward hydrogen evolution reaction with an overpotential of 50 mV to reach 10 mA·cm-2 with Tafel slop of 52.3 mV·dec-1, compared with that of NiFe LDH with 226 mV at 10 mA·cm-2 and Tafel slope of 157.5 mV·dec-1. In addition, Ru/NiFe LDH catalyst also exhibited excellent performance toward oxygen evolution reaction, requiring an overpotential of 231 mV to achieve 50 mA·cm-2, outperforming that of NiFe LDH (237 mV). As expected, Ru/NiFe LDH catalyst showed robust tolerance to long-term working catalysis.
2023, 39(10): 1914-1922
doi: 10.11862/CJIC.2023.152
Abstract:
Four fluorescent probes for zinc ion based on Schiff bases were synthesized from ethylenediamine and salicylaldehyde derivatives and their structures were characterized by 1H NMR, 13C NMR, and IR. The spectral analysis results show that probe L2 has better selectivity and sensitivity to Zn2+ than other probes and the detection limit of probe L2 was 92.15 nmol·L-1. There was a good linear relationship between the fluorescence intensity of probe L2 and the concentration of Zn2+ in a range of 0 to 10 μmol·L-1. The visible fluorescence color change was observed with the naked eye under the ultraviolet lamp. The recognition mechanism was studied by Job's plot, NMR titration experiment, density functional theory calculation, and the crystal structure of the L2 - Zn2+ complex. The results showed that probe L2 was complexed with Zn2+ in a molar ratio of 1∶1. In addition, probe L2 could detect Zn2+ in actual water samples.
Four fluorescent probes for zinc ion based on Schiff bases were synthesized from ethylenediamine and salicylaldehyde derivatives and their structures were characterized by 1H NMR, 13C NMR, and IR. The spectral analysis results show that probe L2 has better selectivity and sensitivity to Zn2+ than other probes and the detection limit of probe L2 was 92.15 nmol·L-1. There was a good linear relationship between the fluorescence intensity of probe L2 and the concentration of Zn2+ in a range of 0 to 10 μmol·L-1. The visible fluorescence color change was observed with the naked eye under the ultraviolet lamp. The recognition mechanism was studied by Job's plot, NMR titration experiment, density functional theory calculation, and the crystal structure of the L2 - Zn2+ complex. The results showed that probe L2 was complexed with Zn2+ in a molar ratio of 1∶1. In addition, probe L2 could detect Zn2+ in actual water samples.
2023, 39(10): 1923-1930
doi: 10.11862/CJIC.2023.149
Abstract:
A novel NaBi(WO4)2 (NBW) ceramic prepared by solid-phase synthesis, the phase structure, morphology, sintering properties, and microwave dielectric properties of NBW ceramic were investigated. NBW is a chemical properties stable compound and was used without special packaging. The NBW ceramic can be sintered densification at temperatures from 625 to 800 ℃ for 1-4 h. The X-ray diffraction showed that the NBW ceramic sintered at temperatures from 625 to 800 ℃ for 2 h is a tetragonal crystal scheelite structure single-phase ceramic. With the increase of sintered temperature, the permittivity and quality factor (Qf value) first increased then decreased, while the temperature coefficient of resonant frequency gradually decreased. The dielectric properties of NBW ceramic sintered at 650 ℃ for 2 h were permittivity of 14.36, Qf of 16 503 GHz, and temperature coefficient of resonant frequency of -1.055 ×10-5 ℃-1. When NBW was co-fired with Ag, it reacted with Ag to form Ag2W2O7, but NBW had chemical compatibility with Au and Al.
A novel NaBi(WO4)2 (NBW) ceramic prepared by solid-phase synthesis, the phase structure, morphology, sintering properties, and microwave dielectric properties of NBW ceramic were investigated. NBW is a chemical properties stable compound and was used without special packaging. The NBW ceramic can be sintered densification at temperatures from 625 to 800 ℃ for 1-4 h. The X-ray diffraction showed that the NBW ceramic sintered at temperatures from 625 to 800 ℃ for 2 h is a tetragonal crystal scheelite structure single-phase ceramic. With the increase of sintered temperature, the permittivity and quality factor (Qf value) first increased then decreased, while the temperature coefficient of resonant frequency gradually decreased. The dielectric properties of NBW ceramic sintered at 650 ℃ for 2 h were permittivity of 14.36, Qf of 16 503 GHz, and temperature coefficient of resonant frequency of -1.055 ×10-5 ℃-1. When NBW was co-fired with Ag, it reacted with Ag to form Ag2W2O7, but NBW had chemical compatibility with Au and Al.
2023, 39(10): 1931-1940
doi: 10.11862/CJIC.2023.162
Abstract:
In this work, a series of cerium coordination polymers (Ce-COPs) with different morphology and electro- chemical signals were synthesized by a simple hydrothermal method using Ce3+ as the central ion and N, N-dimethyl- formamide as the organic ligand through temperature regulation. The polyhedral Ce-COP with the largest electro- chemical signal was selected as the signal probe. Then, a sensitive thrombin (TB) aptamer sensor was designed through the specific recognition between TB and TB aptamer. Under the optimal experimental conditions, the linear range for TB detection was from 1.0 fmol·L-1 to 1.0 nmol·L-1, and the detection limit was 0.94 fmol·L-1. In addition, our method is similar to the results of commercial human thrombin (TM) ELISA reagent detection. In a word, our biosensor possesses good sensitivity, specificity, selectivity, and stability.
In this work, a series of cerium coordination polymers (Ce-COPs) with different morphology and electro- chemical signals were synthesized by a simple hydrothermal method using Ce3+ as the central ion and N, N-dimethyl- formamide as the organic ligand through temperature regulation. The polyhedral Ce-COP with the largest electro- chemical signal was selected as the signal probe. Then, a sensitive thrombin (TB) aptamer sensor was designed through the specific recognition between TB and TB aptamer. Under the optimal experimental conditions, the linear range for TB detection was from 1.0 fmol·L-1 to 1.0 nmol·L-1, and the detection limit was 0.94 fmol·L-1. In addition, our method is similar to the results of commercial human thrombin (TM) ELISA reagent detection. In a word, our biosensor possesses good sensitivity, specificity, selectivity, and stability.
2023, 39(10): 1941-1949
doi: 10.11862/CJIC.2023.159
Abstract:
ZnCaFe2O4/Ag/TiO2 composites were prepared with silver nitrate, tetrabutyl titanate, anhydrous zinc chloride, and ferric chloride hexahydrate as raw materials by sol-gel and solvothermal methods. The samples were characterized and tested by scanning electron microscope, energy spectrum analyzer, X-ray powder diffractometer, X-ray photoelectron spectrometer, vibrating sample magnetometer, ultraviolet visible spectrophotometer. The results showed that ZnCaFe2O4/Ag/TiO2-10 had the best photocatalytic effect, and the degradation rate of dye can reach more than 90% under both ultraviolet and visible light. It had excellent ultraviolet/visible light photocatalytic activity. And after being compounded with ZnCaFe2O4, ZnCaFe2O4/Ag/TiO2 had unique magnetism, which can be recycled under the action of external magnetic field, which makes it possible in practical application. Through magnetic separation technology, the photocatalysis performance of ZnCaFe2O4/Ag/TiO2-10 was still excellent after recycling for five times, which showed excellent magnetism and high photocatalytic cycle stability.
ZnCaFe2O4/Ag/TiO2 composites were prepared with silver nitrate, tetrabutyl titanate, anhydrous zinc chloride, and ferric chloride hexahydrate as raw materials by sol-gel and solvothermal methods. The samples were characterized and tested by scanning electron microscope, energy spectrum analyzer, X-ray powder diffractometer, X-ray photoelectron spectrometer, vibrating sample magnetometer, ultraviolet visible spectrophotometer. The results showed that ZnCaFe2O4/Ag/TiO2-10 had the best photocatalytic effect, and the degradation rate of dye can reach more than 90% under both ultraviolet and visible light. It had excellent ultraviolet/visible light photocatalytic activity. And after being compounded with ZnCaFe2O4, ZnCaFe2O4/Ag/TiO2 had unique magnetism, which can be recycled under the action of external magnetic field, which makes it possible in practical application. Through magnetic separation technology, the photocatalysis performance of ZnCaFe2O4/Ag/TiO2-10 was still excellent after recycling for five times, which showed excellent magnetism and high photocatalytic cycle stability.
Synthesis, structures, and luminescent properties of a series of lanthanide carboxylate-phosphonates
2023, 39(10): 1950-1958
doi: 10.11862/CJIC.2023.167
Abstract:
Three lanthanide carboxylate-phosphonates based on lanthanide nitrate hexahydrate and (5-carboxynaph-thalen-1-yl)phosphonic acid (5-pncH3) formulated as [Pr(5-pnc)(H2O)]·2H2O (1), [Sm(5-pnc)(H2O)]·H2O (2), and [Eu(5-pnc)(H2O)]·H2O (3) has been obtained as single phases under solvothermal conditions. Complexes 1-3 were characterized by single-crystal X-ray diffraction, powder X-ray diffraction, elemental analysis, IR spectra, thermo-gravimetric analysis, and fluorescence spectra. Crystal structures reveal that each lanthanide ion is seven-coordinated by six O atoms from five phosphonate ligands and one O atom from one water molecule. The building blocks [LnO7] of complexes 1-3 are linked into a 1D double metal chain structure by the O—C—O, O—P—O, or —O— units. The 1D double metal chain is fused into a 3D open-framework structure by 5-pnc3-. Complex 3 exhibited very strong characteristic emission bands for the Eu (Ⅲ) ion in the visible region under 330 nm excitation. Complexes 1 and 2 displayed very broad ligand -centered emission bands in the blue light region.
Three lanthanide carboxylate-phosphonates based on lanthanide nitrate hexahydrate and (5-carboxynaph-thalen-1-yl)phosphonic acid (5-pncH3) formulated as [Pr(5-pnc)(H2O)]·2H2O (1), [Sm(5-pnc)(H2O)]·H2O (2), and [Eu(5-pnc)(H2O)]·H2O (3) has been obtained as single phases under solvothermal conditions. Complexes 1-3 were characterized by single-crystal X-ray diffraction, powder X-ray diffraction, elemental analysis, IR spectra, thermo-gravimetric analysis, and fluorescence spectra. Crystal structures reveal that each lanthanide ion is seven-coordinated by six O atoms from five phosphonate ligands and one O atom from one water molecule. The building blocks [LnO7] of complexes 1-3 are linked into a 1D double metal chain structure by the O—C—O, O—P—O, or —O— units. The 1D double metal chain is fused into a 3D open-framework structure by 5-pnc3-. Complex 3 exhibited very strong characteristic emission bands for the Eu (Ⅲ) ion in the visible region under 330 nm excitation. Complexes 1 and 2 displayed very broad ligand -centered emission bands in the blue light region.
2023, 39(10): 1959-1968
doi: 10.11862/CJIC.2023.154
Abstract:
A simple in-situ growth method was presented to synthesize zeolitic imidazolate framework-8 (ZIF-8), one of the most common metal-organic frameworks (MOFs) crystals, onto a carboxymethylated polyacrylonitrile electrospun nanofibers (PAN-COOH NFs). The synthesized ZIF-8/PAN-COOH NFs were characterized by field-emission scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), X-ray powder diffraction (XRD), and Fourier-transform infrared (FTIR) spectroscopy. The characterization results confirmed that the ZIF-8 particles were successfully loaded on the surface of the PAN-COOH NFs. The ability of ZIF-8/PAN-COOH NFs to remove malachite green (MG), a model organic dye, from wastewater was evaluated to examine the potential of this novel material as an adsorbent. The adsorption to MG was consistent with the pseudo -second -order kinetic equation, and the adsorption process was expressed by the Langmuir isotherm model. The maximum adsorption capacity for MG was examined as 3 604 mg·g-1. It is noteworthy that the ZIF-8/PAN-COOH NFs could be easily separated from the dye solution and regenerated through a simple washing process for recycling.
A simple in-situ growth method was presented to synthesize zeolitic imidazolate framework-8 (ZIF-8), one of the most common metal-organic frameworks (MOFs) crystals, onto a carboxymethylated polyacrylonitrile electrospun nanofibers (PAN-COOH NFs). The synthesized ZIF-8/PAN-COOH NFs were characterized by field-emission scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), X-ray powder diffraction (XRD), and Fourier-transform infrared (FTIR) spectroscopy. The characterization results confirmed that the ZIF-8 particles were successfully loaded on the surface of the PAN-COOH NFs. The ability of ZIF-8/PAN-COOH NFs to remove malachite green (MG), a model organic dye, from wastewater was evaluated to examine the potential of this novel material as an adsorbent. The adsorption to MG was consistent with the pseudo -second -order kinetic equation, and the adsorption process was expressed by the Langmuir isotherm model. The maximum adsorption capacity for MG was examined as 3 604 mg·g-1. It is noteworthy that the ZIF-8/PAN-COOH NFs could be easily separated from the dye solution and regenerated through a simple washing process for recycling.
2023, 39(10): 1969-1979
doi: 10.11862/CJIC.2023.147
Abstract:
We report two cyanide-bridged mixed-valence chain-like coordination polymers by the self-assembly reaction of tricyanoferrate(Ⅲ) building blocks (Bu4N)[Fe(PzTp)(CN)3] (PzTp=tetrakis(pyrazolyl)borate) and Co(Ⅱ) ions in the presence of monodentate ligand (E)-1-styryl-1H-imidazole (Bzi). X-ray diffraction analysis indicated that complex [Fe(PzTp)(CN)3]2[Co(Bzi)4]2(ClO4)2·H2O (1) adopts a square-wave type chain structure, while complex [Fe(PzTp) (CN)3]2[Co(Bzi)2]·CH3OH (2) forms double zigzag chains that contain methanol solvent molecules. Magnetic studies revealed that complex 1 displayed a thermally induced spin transition at around 360 K, while complex 2 exhibited a solvent-induced two-step spin transition at approximately 200 K. Variable-temperature infrared spectra confirmed the thermally induced intermetallic charge transfer behavior. Additionally, photomagnetic experiments revealed that complex 1 displayed reversible light-induced charge transfer behavior when alternately irradiated with 808 and 532 nm light, while the charge transfer behavior of complex 2 could be induced by 808 nm irradiation. The magneto-structural relationship analysis indicates that the different hydrogen bonding interactions and local coordination environments of the cobalt sites in complexes 1 and 2 are the main factors contributing to their distinct charge transfer and light-responsive properties.
We report two cyanide-bridged mixed-valence chain-like coordination polymers by the self-assembly reaction of tricyanoferrate(Ⅲ) building blocks (Bu4N)[Fe(PzTp)(CN)3] (PzTp=tetrakis(pyrazolyl)borate) and Co(Ⅱ) ions in the presence of monodentate ligand (E)-1-styryl-1H-imidazole (Bzi). X-ray diffraction analysis indicated that complex [Fe(PzTp)(CN)3]2[Co(Bzi)4]2(ClO4)2·H2O (1) adopts a square-wave type chain structure, while complex [Fe(PzTp) (CN)3]2[Co(Bzi)2]·CH3OH (2) forms double zigzag chains that contain methanol solvent molecules. Magnetic studies revealed that complex 1 displayed a thermally induced spin transition at around 360 K, while complex 2 exhibited a solvent-induced two-step spin transition at approximately 200 K. Variable-temperature infrared spectra confirmed the thermally induced intermetallic charge transfer behavior. Additionally, photomagnetic experiments revealed that complex 1 displayed reversible light-induced charge transfer behavior when alternately irradiated with 808 and 532 nm light, while the charge transfer behavior of complex 2 could be induced by 808 nm irradiation. The magneto-structural relationship analysis indicates that the different hydrogen bonding interactions and local coordination environments of the cobalt sites in complexes 1 and 2 are the main factors contributing to their distinct charge transfer and light-responsive properties.
2023, 39(10): 1980-1990
doi: 10.11862/CJIC.2023.161
Abstract:
Controlling the p-type transmission operation of nanoelectronics remains a major challenge in lowering the Schottky barrier. To solve this problem, we systematically investigated the effects of O atoms adsorption doped on the interlayer interactions and electronic properties of the BP/graphene (BP=blue phosphorus) heterostructures by first-principles calculations incorporating a semiempirical dispersion-correction scheme. The results show that the interfacial binding can be enhanced by O atom adsorption doped inside the interface. The height of the Schottky barrier can be adjusted by changing the concentration of O atom adsorption doped inside the interface. It is further found that by increasing the concentration of O atoms inside the interface, a low p - type Schottky barrier can be obtained, thereby achieving efficient charge transfer. Finally, it is confirmed that the redistribution of the interfacial charge leads to the movement of the Fermi level, which determines the height of the Schottky barrier.
Controlling the p-type transmission operation of nanoelectronics remains a major challenge in lowering the Schottky barrier. To solve this problem, we systematically investigated the effects of O atoms adsorption doped on the interlayer interactions and electronic properties of the BP/graphene (BP=blue phosphorus) heterostructures by first-principles calculations incorporating a semiempirical dispersion-correction scheme. The results show that the interfacial binding can be enhanced by O atom adsorption doped inside the interface. The height of the Schottky barrier can be adjusted by changing the concentration of O atom adsorption doped inside the interface. It is further found that by increasing the concentration of O atoms inside the interface, a low p - type Schottky barrier can be obtained, thereby achieving efficient charge transfer. Finally, it is confirmed that the redistribution of the interfacial charge leads to the movement of the Fermi level, which determines the height of the Schottky barrier.
2023, 39(10): 1991-2002
doi: 10.11862/CJIC.2023.158
Abstract:
Herein, we report the synthesis, structure, adsorption and photocatalytic degradation properties of a novel metal-organic framework [Cu3(ppda)3(tib)2(H2O)4]·6H2O (Cu-MOF) by the selection of the flexible 1,4-phenylenedi-acetic acid (H2ppda) and the rigid 1,3,5-tris(1-imidazolyl) benzene (tib). In Cu-MOF, ppda2- and tib ligands alternately link Cu ions to form 2D polymeric layers, the layer and layer interpenetrate each other by trans-ppda2- to form a stable 3D structure. Cu-MOF has excellent thermal stability and semiconductor properties, so it can be used as a catalyst. Cu-MOF had the best catalytic effect on methylene blue (MB), with a catalytic efficiency of up to 97% and the highest reaction rate constant of 0.019 7 min-1. The main photocatalytic degradation mechanism is the separation of the photogenerated electron and hole pair of the catalyst under the light excitation, and the redox reaction occurs to produce the active species to degrade the dye and eventually decompose into carbon dioxide and water. Cu - MOF exhibited high adsorption capacity after adding NaCl (200 g·L-1) to MB solution (87.23 mg·g-1). The adsorption process is a spontaneous monolayer chemisorption process illustrated by the pseudo-second-order kinetic and Langmuir isotherm models and thermodynamic studies.
Herein, we report the synthesis, structure, adsorption and photocatalytic degradation properties of a novel metal-organic framework [Cu3(ppda)3(tib)2(H2O)4]·6H2O (Cu-MOF) by the selection of the flexible 1,4-phenylenedi-acetic acid (H2ppda) and the rigid 1,3,5-tris(1-imidazolyl) benzene (tib). In Cu-MOF, ppda2- and tib ligands alternately link Cu ions to form 2D polymeric layers, the layer and layer interpenetrate each other by trans-ppda2- to form a stable 3D structure. Cu-MOF has excellent thermal stability and semiconductor properties, so it can be used as a catalyst. Cu-MOF had the best catalytic effect on methylene blue (MB), with a catalytic efficiency of up to 97% and the highest reaction rate constant of 0.019 7 min-1. The main photocatalytic degradation mechanism is the separation of the photogenerated electron and hole pair of the catalyst under the light excitation, and the redox reaction occurs to produce the active species to degrade the dye and eventually decompose into carbon dioxide and water. Cu - MOF exhibited high adsorption capacity after adding NaCl (200 g·L-1) to MB solution (87.23 mg·g-1). The adsorption process is a spontaneous monolayer chemisorption process illustrated by the pseudo-second-order kinetic and Langmuir isotherm models and thermodynamic studies.
2023, 39(10): 2003-2008
doi: 10.11862/CJIC.2023.151
Abstract:
A 2p-3d hetero-spin complex, namely [Co(hfac)2(NIT-PyzMe-PhCHO)] (1), where hfac=hexafluoroacetyl-acetone, NIT-PyzMe-PhCHO=2-(3-(1H-imidazol-1-ylmethyl)benzaldehyde)-4, 4, 5, 5-tetramethylimidazoline-1-oxyl-3-oxide, has been successfully isolated and characterized. Complex 1 displays a mononuclear structure. Strong antifer-romagnetic interaction was detected between the CoⅡ ion and the directly coordinated nitroxide group. Moreover, the frequency-dependent out-of-phase signals related to the slow relaxation of magnetization verify the typical single-molecule magnet behavior of the system.
A 2p-3d hetero-spin complex, namely [Co(hfac)2(NIT-PyzMe-PhCHO)] (1), where hfac=hexafluoroacetyl-acetone, NIT-PyzMe-PhCHO=2-(3-(1H-imidazol-1-ylmethyl)benzaldehyde)-4, 4, 5, 5-tetramethylimidazoline-1-oxyl-3-oxide, has been successfully isolated and characterized. Complex 1 displays a mononuclear structure. Strong antifer-romagnetic interaction was detected between the CoⅡ ion and the directly coordinated nitroxide group. Moreover, the frequency-dependent out-of-phase signals related to the slow relaxation of magnetization verify the typical single-molecule magnet behavior of the system.
2023, 39(10): 2009-2019
doi: 10.11862/CJIC.2023.148
Abstract:
A new 2D nickel (Ⅱ) coordination polymer (Ni - CP) has been synthesized hydrothermally, named as [Ni(DDB)0.5(2, 2'-bipy)(H2O)]·H2O (H4DDB=1, 4-di(3, 5-dicarboylphenoxy) benzene, 2, 2'-bipy=2, 2'-bipyridine), and characterized by element analysis, thermogravimetric analysis, powder X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. Single-crystal structural analysis shows that the coordination polymer possesses a 2D waved network through DDB4- ligand in μ4 fashion. Ag-loaded products (Ag@Ni-CP) with Schottky junction were prepared by the photoreduction method. Photocatalytic degradation performance of Ni-CP and Ag@ Ni-CP were investigated, and the latter exhibited excellent degradation effect, especially for rhodamine B and methylene blue with a high degradation rate of 99% rapidly in 60 min. Ag@Ni-CP exhibited higher and faster degradation performance than the reported MOF catalyst materials. The photocatalytic mechanism was investigated by free radical trapping experiments.
A new 2D nickel (Ⅱ) coordination polymer (Ni - CP) has been synthesized hydrothermally, named as [Ni(DDB)0.5(2, 2'-bipy)(H2O)]·H2O (H4DDB=1, 4-di(3, 5-dicarboylphenoxy) benzene, 2, 2'-bipy=2, 2'-bipyridine), and characterized by element analysis, thermogravimetric analysis, powder X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. Single-crystal structural analysis shows that the coordination polymer possesses a 2D waved network through DDB4- ligand in μ4 fashion. Ag-loaded products (Ag@Ni-CP) with Schottky junction were prepared by the photoreduction method. Photocatalytic degradation performance of Ni-CP and Ag@ Ni-CP were investigated, and the latter exhibited excellent degradation effect, especially for rhodamine B and methylene blue with a high degradation rate of 99% rapidly in 60 min. Ag@Ni-CP exhibited higher and faster degradation performance than the reported MOF catalyst materials. The photocatalytic mechanism was investigated by free radical trapping experiments.
2023, 39(10): 2020-2032
doi: 10.11862/CJIC.2023.157
Abstract:
Peanut shells were used as raw materials and activated to peanut shell-based porous carbon (HC) by KOH. Nitrogen adsorption-desorption studies showed that the obtained porous carbon featured a total surface area as high as 1 645 m2·g-1. Pd-Co/HC catalyst was prepared by the impregnation reduction method, in which HC was the carrier. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis demonstrated that Co in the catalyst was mainly in the form of Co and CoO, and Co was entered into the crystal lattice of Pd and formed a Pd-Co alloy. The TEM image of Pd-Co/HC0.5-700 showed that numerous Pd-Co nanoparticles were successfully dispersed in the prepared porous carbon with a small particle size (ca. 4 nm). Pd-Co/HC0.5-700 exhibited apparent electrocatalytic activity, CO tolerance, and stability towards methanol electrooxidation in alkaline media. This remarkable high performance can be attributed to the large surface area of the biomass carrier and the doping of Co into Pd.
Peanut shells were used as raw materials and activated to peanut shell-based porous carbon (HC) by KOH. Nitrogen adsorption-desorption studies showed that the obtained porous carbon featured a total surface area as high as 1 645 m2·g-1. Pd-Co/HC catalyst was prepared by the impregnation reduction method, in which HC was the carrier. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis demonstrated that Co in the catalyst was mainly in the form of Co and CoO, and Co was entered into the crystal lattice of Pd and formed a Pd-Co alloy. The TEM image of Pd-Co/HC0.5-700 showed that numerous Pd-Co nanoparticles were successfully dispersed in the prepared porous carbon with a small particle size (ca. 4 nm). Pd-Co/HC0.5-700 exhibited apparent electrocatalytic activity, CO tolerance, and stability towards methanol electrooxidation in alkaline media. This remarkable high performance can be attributed to the large surface area of the biomass carrier and the doping of Co into Pd.
