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2021 Volume 37 Issue 10
2021, 37(10): 1713-1726
doi: 10.11862/CJIC.2021.206
Abstract:
As a typical two-dimensional organic polymeric semiconductor photocatalyst, graphitic carbon nitride (g-C3N4) has attracted much attention due to its visible-light-responsive property, chemical structure stability and excellent biocompatibility, indicating its promising applications in fields of energy and environment. However, there are many defects both in the bulk and on the surface of g-C3N4 due to the incomplete polymerization, which become the charge recombination centers, resulting in a poor photoreactivity. Recently, the study on the high-photoreactive crystalline carbon nitride (CCN) has elicited considerable attention. In this mini review paper, typical methods in fabrication of CCN, together with the modification strategies, are summarized. The five methods in synthesizing CCN include traditional molten, precursor-preheated molten, solid salt, solvothermal reaction and protonation synthesis, and the modification strategies include defects engineering, morphology-controlling, single-atom modification and materials hybridization. We mainly focuse on the introduction of principles, structure properties and photocatalytic performances of CCN. Finally, the methods in preparation and modification of CCN are commented, and the study of CCN in the future is also outlooked.
As a typical two-dimensional organic polymeric semiconductor photocatalyst, graphitic carbon nitride (g-C3N4) has attracted much attention due to its visible-light-responsive property, chemical structure stability and excellent biocompatibility, indicating its promising applications in fields of energy and environment. However, there are many defects both in the bulk and on the surface of g-C3N4 due to the incomplete polymerization, which become the charge recombination centers, resulting in a poor photoreactivity. Recently, the study on the high-photoreactive crystalline carbon nitride (CCN) has elicited considerable attention. In this mini review paper, typical methods in fabrication of CCN, together with the modification strategies, are summarized. The five methods in synthesizing CCN include traditional molten, precursor-preheated molten, solid salt, solvothermal reaction and protonation synthesis, and the modification strategies include defects engineering, morphology-controlling, single-atom modification and materials hybridization. We mainly focuse on the introduction of principles, structure properties and photocatalytic performances of CCN. Finally, the methods in preparation and modification of CCN are commented, and the study of CCN in the future is also outlooked.
2021, 37(10): 1727-1737
doi: 10.11862/CJIC.2021.217
Abstract:
A new two-component photochromic Ag (Ⅰ) complex 1 was synthesized by employing two diarylethenes bearing separated absorption wavelengths as ligands, i.e. 1, 2-bis(2'-methyl-5'-(4″-cyanopheny)-3'-thienyl) perfluorocyclopentene (L1) and cis-1, 2-dicyano-1, 2-bis(2', 4', 5'-trimethyl-3'-thienyl) ethylene (L2), Ag(Ⅰ) as metal ions as well as strong coordinating CF3COO- as anions. The complex was characterized structurally by IR, 1H NMR and MS. The multi-colored photochromism of complex 1 was investigated in thtrahydrofuran (THF) and polymethylmethacrylate (PMMA) films by UV-Vis spectra with the mixture of two ligands as control. The results show the coordination of silver ions doesn't inhibit the photochromism but regulates the photo-isomerizations of the two ligands. The four color transformations of yellow, blue, red and purple in complex 1 were realized successfully by the selective stepwise photo-isomerization of the distinct ligands upon irradiation with combination of different wavelengths lights (254 nm, 405 nm, > 550 nm).
A new two-component photochromic Ag (Ⅰ) complex 1 was synthesized by employing two diarylethenes bearing separated absorption wavelengths as ligands, i.e. 1, 2-bis(2'-methyl-5'-(4″-cyanopheny)-3'-thienyl) perfluorocyclopentene (L1) and cis-1, 2-dicyano-1, 2-bis(2', 4', 5'-trimethyl-3'-thienyl) ethylene (L2), Ag(Ⅰ) as metal ions as well as strong coordinating CF3COO- as anions. The complex was characterized structurally by IR, 1H NMR and MS. The multi-colored photochromism of complex 1 was investigated in thtrahydrofuran (THF) and polymethylmethacrylate (PMMA) films by UV-Vis spectra with the mixture of two ligands as control. The results show the coordination of silver ions doesn't inhibit the photochromism but regulates the photo-isomerizations of the two ligands. The four color transformations of yellow, blue, red and purple in complex 1 were realized successfully by the selective stepwise photo-isomerization of the distinct ligands upon irradiation with combination of different wavelengths lights (254 nm, 405 nm, > 550 nm).
2021, 37(10): 1738-1744
doi: 10.11862/CJIC.2021.207
Abstract:
Two new polypyridine dinuclear nickel (Ⅱ) complexes[Ni2(L)2Cl2](ClO4)2·3H2O (1) and[Ni2(L)2Cl2](PF6)2 (2) (L=N, N-bis(pyridin-2-ylmethyl)-4-(4-((pyridin-2-ylmethyl)amino)benzyl)aniline) were synthesized, and their structures were determined by X-ray single crystal diffraction, elemental analysis and infrared spectroscopy. Moreover, the in vitro toxic effects of the two complexes on cancer cells (HeLa, BGC-823, NCI-H460, HepG-2) were tested by thiazole blue (MTT) method, and the results indicate that the two complexes showed good toxicity on NCIH460 cells. IC50=(26.0±2.2) μmol·L-1 (1), (31.3±2.7) μmol·L-1 (2). The cytotoxic mechanism of complex 1 towards NCI-H460 cells was further explored by Hoechst 33342 staining, detection of intracellular reactive oxygen species levels and measurement of mitochondrial membrane potential change. The results demonstrate that complex 1 is likely to induce cell apoptosis through the mitochondrial pathway, thereby causing lethal effects on cancer cells.
Two new polypyridine dinuclear nickel (Ⅱ) complexes[Ni2(L)2Cl2](ClO4)2·3H2O (1) and[Ni2(L)2Cl2](PF6)2 (2) (L=N, N-bis(pyridin-2-ylmethyl)-4-(4-((pyridin-2-ylmethyl)amino)benzyl)aniline) were synthesized, and their structures were determined by X-ray single crystal diffraction, elemental analysis and infrared spectroscopy. Moreover, the in vitro toxic effects of the two complexes on cancer cells (HeLa, BGC-823, NCI-H460, HepG-2) were tested by thiazole blue (MTT) method, and the results indicate that the two complexes showed good toxicity on NCIH460 cells. IC50=(26.0±2.2) μmol·L-1 (1), (31.3±2.7) μmol·L-1 (2). The cytotoxic mechanism of complex 1 towards NCI-H460 cells was further explored by Hoechst 33342 staining, detection of intracellular reactive oxygen species levels and measurement of mitochondrial membrane potential change. The results demonstrate that complex 1 is likely to induce cell apoptosis through the mitochondrial pathway, thereby causing lethal effects on cancer cells.
2021, 37(10): 1745-1752
doi: 10.11862/CJIC.2021.202
Abstract:
Magnesium-doped tricalcium aluminate (Mg-C3A) was successfully prepared through solid reaction method. The crystal structure and morphology of Mg-C3A with various Mg contents were analyzed via X-ray diffraction, Raman spectra, scanning electron microscope and high-resolution transmission electron microscope to explore the preparation mechanism. The results showed that Mg-C3A was composed of C3A isomorphism formed by the replacement of Ca with Mg and the surface MgO, in which the Mg doping did not change the cubic symmetric structure and morphology of C3A. The simultaneous removal behavior of nitrogen (NH4+) and phosphorus (PO43-) by Mg-C3A were investigated by batch experiments (e. g., Mg-C3A dosage, reaction time and real wastewater treatment), which revealed the maximum capacity was 65.2 and 20.2 mg·g-1 at 12 h, respectively, conforming to the pseudo-secondorder kinetic model. Besides, the removal mechanisms were comprehensively explored by microscopic characterizations. The released ions (i.e., Mg2+ and Al3+) of Mg-C3A play a major role in the removal of NH4+ and PO43- via the formation of struvite and AlPO4; the OH- benefits for the removal of excessive NH4+ via neutralization.
Magnesium-doped tricalcium aluminate (Mg-C3A) was successfully prepared through solid reaction method. The crystal structure and morphology of Mg-C3A with various Mg contents were analyzed via X-ray diffraction, Raman spectra, scanning electron microscope and high-resolution transmission electron microscope to explore the preparation mechanism. The results showed that Mg-C3A was composed of C3A isomorphism formed by the replacement of Ca with Mg and the surface MgO, in which the Mg doping did not change the cubic symmetric structure and morphology of C3A. The simultaneous removal behavior of nitrogen (NH4+) and phosphorus (PO43-) by Mg-C3A were investigated by batch experiments (e. g., Mg-C3A dosage, reaction time and real wastewater treatment), which revealed the maximum capacity was 65.2 and 20.2 mg·g-1 at 12 h, respectively, conforming to the pseudo-secondorder kinetic model. Besides, the removal mechanisms were comprehensively explored by microscopic characterizations. The released ions (i.e., Mg2+ and Al3+) of Mg-C3A play a major role in the removal of NH4+ and PO43- via the formation of struvite and AlPO4; the OH- benefits for the removal of excessive NH4+ via neutralization.
2021, 37(10): 1753-1763
doi: 10.11862/CJIC.2021.211
Abstract:
Herein, anatase TiO2 nanoparticles with co-exposed {101}/[111]-facets (ethanoic acid-TiO2 and no control agent-TiO2, namely HAc-TiO2 and NO-TiO2) and co-exposed {101}/{010}/[111]-facets (formic acid-TiO2 and hydrofluoric acid-TiO2, namely FA-TiO2 and HF-TiO2) were prepared by a mild solvothermal method using tetrabutyl titanate as titanium source. The crystal structure, morphology, specific surface area, pore size distribution, optical properties, transformation and recombination of charge carriers (electron and hole) of the samples were characterized. The photocatalytic performance and cycling performance of the samples were also evaluated. The results showed that as-prepared HF-TiO2 with co-exposed {101}/{010}/[111]-facets exhibited the highest photocatalytic activity in the process of photocatalytic degradation of rhodamine B solution (or p-nitrophenol solution), and its degradation efficiency was 97.35% (or 68.57%), which was 1.06 times (or 1.09 times), 1.18 times (or 1.14 times), 1.35 times (or 2.33 times) and 4.88 times (or 5.80 times) of FA-TiO2, HAc-TiO2, BD-TiO2 and NO-TiO2, respectively. The highest photocatalytic activity of HF-TiO2 could be attributed to the synergistic effect of the maximum crystallinity, larger surface energy, superior surface atomic structure and surface electronic structure, lowest photoluminescence intensity, fastest charge transfer rate and minimum carrier recombination rate.
Herein, anatase TiO2 nanoparticles with co-exposed {101}/[111]-facets (ethanoic acid-TiO2 and no control agent-TiO2, namely HAc-TiO2 and NO-TiO2) and co-exposed {101}/{010}/[111]-facets (formic acid-TiO2 and hydrofluoric acid-TiO2, namely FA-TiO2 and HF-TiO2) were prepared by a mild solvothermal method using tetrabutyl titanate as titanium source. The crystal structure, morphology, specific surface area, pore size distribution, optical properties, transformation and recombination of charge carriers (electron and hole) of the samples were characterized. The photocatalytic performance and cycling performance of the samples were also evaluated. The results showed that as-prepared HF-TiO2 with co-exposed {101}/{010}/[111]-facets exhibited the highest photocatalytic activity in the process of photocatalytic degradation of rhodamine B solution (or p-nitrophenol solution), and its degradation efficiency was 97.35% (or 68.57%), which was 1.06 times (or 1.09 times), 1.18 times (or 1.14 times), 1.35 times (or 2.33 times) and 4.88 times (or 5.80 times) of FA-TiO2, HAc-TiO2, BD-TiO2 and NO-TiO2, respectively. The highest photocatalytic activity of HF-TiO2 could be attributed to the synergistic effect of the maximum crystallinity, larger surface energy, superior surface atomic structure and surface electronic structure, lowest photoluminescence intensity, fastest charge transfer rate and minimum carrier recombination rate.
2021, 37(10): 1764-1772
doi: 10.11862/CJIC.2021.200
Abstract:
The research results show size- and shape-dependent infrared absorption properties for binary and ternary tungsten-oxides. However, there is no universal theory in both physical principle and calculation method for binary and ternary tungsten-oxides. In this study, the correlation between the optical absorption characteristics and onedimensional material length was deduced based on Mie scattering theory, and the correlation of tungsten oxide based materials was studied by means of theoretical deductions and experimental verifications. Firstly, from a perspective of deduction and calculation based on Mie scattering theory reveal that increasing the length of both nanoCs0.2WO3 and W18O49 can improve their near-infrared absorption performance. Secondly, the near-infrared absorption performance of synthesized Cs0.2WO3 nanorods and W18O49 nanowires with different lengths was tested. The experimental data is consistent with the theoretical calculations and simulation results. Cs0.2WO3 nanorods and W18O49 nanowires have different trends with particle length between 2 500 and 20 000 nm, and the infrared absorption properties of Cs0.2WO3 nanorods were proportional to particle length. Finally, the photothermal effects of Cs0.2WO3 nanorods and W18O49 nanowires were tested. And the amplification of temperature reached 18.5% and 12.7% with the increase of particle length for both nano-tungsten oxides, respectively.
The research results show size- and shape-dependent infrared absorption properties for binary and ternary tungsten-oxides. However, there is no universal theory in both physical principle and calculation method for binary and ternary tungsten-oxides. In this study, the correlation between the optical absorption characteristics and onedimensional material length was deduced based on Mie scattering theory, and the correlation of tungsten oxide based materials was studied by means of theoretical deductions and experimental verifications. Firstly, from a perspective of deduction and calculation based on Mie scattering theory reveal that increasing the length of both nanoCs0.2WO3 and W18O49 can improve their near-infrared absorption performance. Secondly, the near-infrared absorption performance of synthesized Cs0.2WO3 nanorods and W18O49 nanowires with different lengths was tested. The experimental data is consistent with the theoretical calculations and simulation results. Cs0.2WO3 nanorods and W18O49 nanowires have different trends with particle length between 2 500 and 20 000 nm, and the infrared absorption properties of Cs0.2WO3 nanorods were proportional to particle length. Finally, the photothermal effects of Cs0.2WO3 nanorods and W18O49 nanowires were tested. And the amplification of temperature reached 18.5% and 12.7% with the increase of particle length for both nano-tungsten oxides, respectively.
2021, 37(10): 1773-1781
doi: 10.11862/CJIC.2021.199
Abstract:
In this work, micron-sized commercial Si-Al alloy powders were used as raw material to in-situ prepare porous silicon/CoOx composites by acid etching, photochemical deposition and subsequently reduction process. The effects of different photodeposition times on the morphologies and lithium storage properties of pSi@CoOx materials were explored. The introduction of CoOx nanosheets improves the electronic conductivity and structural stability of the composites. Even at the current density of 1 A·g-1, pSi@CoOx-5 delivered a specific capacity of 774.2 mAh·g-1 after 200 cycles.
In this work, micron-sized commercial Si-Al alloy powders were used as raw material to in-situ prepare porous silicon/CoOx composites by acid etching, photochemical deposition and subsequently reduction process. The effects of different photodeposition times on the morphologies and lithium storage properties of pSi@CoOx materials were explored. The introduction of CoOx nanosheets improves the electronic conductivity and structural stability of the composites. Even at the current density of 1 A·g-1, pSi@CoOx-5 delivered a specific capacity of 774.2 mAh·g-1 after 200 cycles.
2021, 37(10): 1782-1792
doi: 10.11862/CJIC.2021.210
Abstract:
High-voltage LiNi0.5Mn1.5O4 cathode materials doped with different rare earth elements were prepared by low temperature combustion method. The effects of different doping ratios (molar ratios of 0.5%, 1%, 2%) and different kinds of rare earth elements (La, Ce, Yb) on the material performance were investigated, and the influence mechanism was explored by X-ray diffraction, Raman spectrum, electron paramagnetic resonance and galvanostatic intermittent titration technique. X-ray diffraction pattern illustrates that rare earth doping can inhibit the generation of LixNi1-xO phase. The inductively coupled plasma spectroscopy illustrates that the doped rare earth elements are basically in accordance with the design proportion. Raman spectrum illustrates that rare earth elements can increase the ordered phase of the material and Ce doped sample has the most ordered phase. In combination with electron paramagnetic resonance oxygen vacancy test, it is found that Ce doped sample induces the increase of the proportion of ordered phase in the material, thus improving the stability of the material. Galvanostatic intermittent titration technique test showed that the diffusion coefficient of Ce-doped LiNi0.5Mn1.5O4 material was about 15 times higher than the undoped sample. In different doping proportion, the material with 1% doping amount had the best performance. Among the samples doping with the best amount of three rare earth elements, Ce doped samples had the best doping performance, and the specific discharge capacity of the first discharge can reach 133.3 mAh·g-1, which was higher than the undoped group and the first discharge efficiency was increased by 18%. After 200 cycles at 1C, the capacity retention rate was 102%, which was 8% higher than the undoped group.
High-voltage LiNi0.5Mn1.5O4 cathode materials doped with different rare earth elements were prepared by low temperature combustion method. The effects of different doping ratios (molar ratios of 0.5%, 1%, 2%) and different kinds of rare earth elements (La, Ce, Yb) on the material performance were investigated, and the influence mechanism was explored by X-ray diffraction, Raman spectrum, electron paramagnetic resonance and galvanostatic intermittent titration technique. X-ray diffraction pattern illustrates that rare earth doping can inhibit the generation of LixNi1-xO phase. The inductively coupled plasma spectroscopy illustrates that the doped rare earth elements are basically in accordance with the design proportion. Raman spectrum illustrates that rare earth elements can increase the ordered phase of the material and Ce doped sample has the most ordered phase. In combination with electron paramagnetic resonance oxygen vacancy test, it is found that Ce doped sample induces the increase of the proportion of ordered phase in the material, thus improving the stability of the material. Galvanostatic intermittent titration technique test showed that the diffusion coefficient of Ce-doped LiNi0.5Mn1.5O4 material was about 15 times higher than the undoped sample. In different doping proportion, the material with 1% doping amount had the best performance. Among the samples doping with the best amount of three rare earth elements, Ce doped samples had the best doping performance, and the specific discharge capacity of the first discharge can reach 133.3 mAh·g-1, which was higher than the undoped group and the first discharge efficiency was increased by 18%. After 200 cycles at 1C, the capacity retention rate was 102%, which was 8% higher than the undoped group.
2021, 37(10): 1793-1800
doi: 10.11862/CJIC.2021.216
Abstract:
The three-dimensional N and S co-doped graphene loaded cobalt sulfide nanoparticles oxygen evolution electrocatalyst (CoS/N/S/rGO) was prepared by using D-glucosamine as the Co dispersant and carbon source, thiourea as the nitrogen source and sulfur source, and NaCl as the template, achieving N and S co-doping and uniformly loading two kinds of nanoparticles Co9S8 and Co4S3. CoS/N/S/rGO had good oxygen reduction reaction (ORR) activity with initial potential of 960 mV and half-wave potential of 815 mV, respectively, which was similar to commercial Pt/C. In addition, CoS/N/S/rGO showed obvious four-electron transfer characteristics and ultra-low hydrogen peroxide production rate. Compared with Pt/C based zinc-air battery, CoS/N/S/rGO based zinc-air battery showed higher constant current discharge performance and better stability in 6 mol·L-1 KOH and 0.2 mol·L-1 Zn(CH3COO)2 alkaline electrolyte.
The three-dimensional N and S co-doped graphene loaded cobalt sulfide nanoparticles oxygen evolution electrocatalyst (CoS/N/S/rGO) was prepared by using D-glucosamine as the Co dispersant and carbon source, thiourea as the nitrogen source and sulfur source, and NaCl as the template, achieving N and S co-doping and uniformly loading two kinds of nanoparticles Co9S8 and Co4S3. CoS/N/S/rGO had good oxygen reduction reaction (ORR) activity with initial potential of 960 mV and half-wave potential of 815 mV, respectively, which was similar to commercial Pt/C. In addition, CoS/N/S/rGO showed obvious four-electron transfer characteristics and ultra-low hydrogen peroxide production rate. Compared with Pt/C based zinc-air battery, CoS/N/S/rGO based zinc-air battery showed higher constant current discharge performance and better stability in 6 mol·L-1 KOH and 0.2 mol·L-1 Zn(CH3COO)2 alkaline electrolyte.
2021, 37(10): 1801-1808
doi: 10.11862/CJIC.2021.209
Abstract:
Two diphenyltin complexes, [(C6H5(O)C＝N—N＝C(Ph)—(Ph)C＝N—N＝C(O)—C6H5)2SnPh2(CH3OH)]· 3CH3OH (1) and[(o-OH—C6H4(O)C＝N—N＝C(Ph)— (Ph)C＝N—N＝C(O)— (o-OH—C6H4))2SnPh2(CH3OH)] · CH3OH (2), have been synthesized via the reaction of diphenyl ethylenedione benzoyl hydrazone or diphenylethylenedione salicylhydrazone with diphenyltin dichloride. Complexes 1 and 2 have been characterized by IR, 1H NMR, 13C NMR, 119Sn NMR spectra, elemental analysis, HRMS and the crystal structures have been determined by X-ray diffraction. The thermostability of complexes 1 and 2 were analyzed, and in vitro antitumor activities of both the complexes were evaluated by MTT against three human cancer cell lines. It was found that complex 2 showed a slightly better inhibitory effect on cancer cells NCI-H460, HepG2, MCF7. The interaction of complex 2 with DNA was investigated using UV-Vis absorption spectroscopy and fluorescence quench spectra. It was found that complex 2 could bind to DNA through an intercalation mode.
Two diphenyltin complexes, [(C6H5(O)C＝N—N＝C(Ph)—(Ph)C＝N—N＝C(O)—C6H5)2SnPh2(CH3OH)]· 3CH3OH (1) and[(o-OH—C6H4(O)C＝N—N＝C(Ph)— (Ph)C＝N—N＝C(O)— (o-OH—C6H4))2SnPh2(CH3OH)] · CH3OH (2), have been synthesized via the reaction of diphenyl ethylenedione benzoyl hydrazone or diphenylethylenedione salicylhydrazone with diphenyltin dichloride. Complexes 1 and 2 have been characterized by IR, 1H NMR, 13C NMR, 119Sn NMR spectra, elemental analysis, HRMS and the crystal structures have been determined by X-ray diffraction. The thermostability of complexes 1 and 2 were analyzed, and in vitro antitumor activities of both the complexes were evaluated by MTT against three human cancer cell lines. It was found that complex 2 showed a slightly better inhibitory effect on cancer cells NCI-H460, HepG2, MCF7. The interaction of complex 2 with DNA was investigated using UV-Vis absorption spectroscopy and fluorescence quench spectra. It was found that complex 2 could bind to DNA through an intercalation mode.
2021, 37(10): 1809-1818
doi: 10.11862/CJIC.2021.215
Abstract:
Direct Z-scheme LaNiO3/Mn0.2Cd0.8S heterojunction photocatalysts were synthesized in situ by the introduction of Mn2+ ions in the hydrothermal preparation of CdS using LaNiO3 nanoparticles matrix and fully characterized by field emission scanning electron microscope, powder X-ray diffraction, X-ray photoelectron spectroscopy, UV-Vis diffuse reflectance spectra, N2 adsorption-desorption test and electrochemistry test. LaNiO3/Mn0.2Cd0.8S heterojunction photocatalysts showed improved photocatalytic H2 evolution and stability. The photocatalytic H2 evolution over LaNiO3/Mn0.2Cd0.8S heterojunction photocatalysts reached to 1 190.3 μmol in 5 h, which was 25-fold and 10-fold enhanced compared with pure CdS and Mn0.2Cd0.8S. The enhanced performance of LaNiO3/Mn0.2Cd0.8S heterojunction photocatalysts was ascribed to the formation of heterojunction between LaNiO3 and Mn0.2Cd0.8S as well as the introduced Mn2+ ion, which both can inhibit the recombination of the photoinduced electron-hole. Based on the above results, the direct Z-scheme photocatalytic reaction mechanism was proposed to elucidate the improved performance of LaNiO3/Mn0.2Cd0.8S heterojunction photocatalysts.
Direct Z-scheme LaNiO3/Mn0.2Cd0.8S heterojunction photocatalysts were synthesized in situ by the introduction of Mn2+ ions in the hydrothermal preparation of CdS using LaNiO3 nanoparticles matrix and fully characterized by field emission scanning electron microscope, powder X-ray diffraction, X-ray photoelectron spectroscopy, UV-Vis diffuse reflectance spectra, N2 adsorption-desorption test and electrochemistry test. LaNiO3/Mn0.2Cd0.8S heterojunction photocatalysts showed improved photocatalytic H2 evolution and stability. The photocatalytic H2 evolution over LaNiO3/Mn0.2Cd0.8S heterojunction photocatalysts reached to 1 190.3 μmol in 5 h, which was 25-fold and 10-fold enhanced compared with pure CdS and Mn0.2Cd0.8S. The enhanced performance of LaNiO3/Mn0.2Cd0.8S heterojunction photocatalysts was ascribed to the formation of heterojunction between LaNiO3 and Mn0.2Cd0.8S as well as the introduced Mn2+ ion, which both can inhibit the recombination of the photoinduced electron-hole. Based on the above results, the direct Z-scheme photocatalytic reaction mechanism was proposed to elucidate the improved performance of LaNiO3/Mn0.2Cd0.8S heterojunction photocatalysts.
2021, 37(10): 1819-1827
doi: 10.11862/CJIC.2021.201
Abstract:
A series of PdxMo/C (atomic ratio x of Pd/Mo was 1, 2, 3, 4, 5, respectively) catalysts in dichloromethane were prepared by phase transfer method using tetrabutylammonium hydroxide as phase transfer agent and sodium borohydride as reducing agent. Trancmission electron microscope (TEM) images showed that PdxMo/C was 2~4 nm circular particles with uniform size and good dispersion. The X-ray diffraction (XRD) results showed that the crystal lattice of Pd was expanded by adding the second component Mo, and the lattice structure of Pd was adjusted. In addition, X-ray photoelectron spectroscopy (XPS) results show that compared with Pd/C, the binding energy of Pd3d5/2 for Pd4Mo/C was shifted by 0.50 eV to the lower direction, indicating that Pd with higher electronegativity absorbs electrons from Mo, and the electronic structure changes. The results of oxygen reduction reaction (ORR) showed that the activity of different ratios of PdxMo/C was better than that of Pd/C, and the ORR activity was the best when x=4. The initial oxidation potential and half-wave potential were 0.876 and 0.813 V, respectively, which were higher than that of 0.870 and 0.810 V of commercial Pt/C. In addition, the current density retained 82.9% after 3 h of operation, showing a significant advantage over commercial Pt/C.
A series of PdxMo/C (atomic ratio x of Pd/Mo was 1, 2, 3, 4, 5, respectively) catalysts in dichloromethane were prepared by phase transfer method using tetrabutylammonium hydroxide as phase transfer agent and sodium borohydride as reducing agent. Trancmission electron microscope (TEM) images showed that PdxMo/C was 2~4 nm circular particles with uniform size and good dispersion. The X-ray diffraction (XRD) results showed that the crystal lattice of Pd was expanded by adding the second component Mo, and the lattice structure of Pd was adjusted. In addition, X-ray photoelectron spectroscopy (XPS) results show that compared with Pd/C, the binding energy of Pd3d5/2 for Pd4Mo/C was shifted by 0.50 eV to the lower direction, indicating that Pd with higher electronegativity absorbs electrons from Mo, and the electronic structure changes. The results of oxygen reduction reaction (ORR) showed that the activity of different ratios of PdxMo/C was better than that of Pd/C, and the ORR activity was the best when x=4. The initial oxidation potential and half-wave potential were 0.876 and 0.813 V, respectively, which were higher than that of 0.870 and 0.810 V of commercial Pt/C. In addition, the current density retained 82.9% after 3 h of operation, showing a significant advantage over commercial Pt/C.
2021, 37(10): 1828-1838
doi: 10.11862/CJIC.2021.213
Abstract:
BiOBr/BiPO4 p-n heterojunction composite photocatalyst was successfully prepared by one-step hydrothermal method. The physical properties of the samples were characterized by X-ray powder diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), N2 adsorption-desorption isotherm, X-ray photoelectron spectroscopy (XPS) and UV-Vis diffuse reflection spectrum (UV-Vis DRS). The photocatalytic activity of the sample was evaluated by degradation of rhodamine B under visible light irradiation (λ > 420 nm), and the effect of BiPO4 content on the photocatalytic activity of the prepared materials was investigated. The main active species in the photocatalytic reaction were determined by capturing experiment, and the photocatalytic mechanism was proposed. The results showed that the optimum molar content of BiPO4 was 10%, and the optimal catalyst showed the best photocatalytic activity with the reaction rate constant of 0.14 min-1, which was about 3.7 times that of pure BiOBr. And it also exhibited amostly unchanged photocatalytic activity after three cycling experiments. The improvement of catalytic activity is mainly due to the formation of BiPO4/BiOBr heterojunction, which improves the separation efficiency of photo-generated carriers. In addition, the enhanced adsorption capacity of pollutants promotes the improvement of catalytic activity. The hole and superoxide radical are the main active species in the photocatalytic process, and the order of the role of the three species is hole > superoxide radical > hydroxyl radical.
BiOBr/BiPO4 p-n heterojunction composite photocatalyst was successfully prepared by one-step hydrothermal method. The physical properties of the samples were characterized by X-ray powder diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), N2 adsorption-desorption isotherm, X-ray photoelectron spectroscopy (XPS) and UV-Vis diffuse reflection spectrum (UV-Vis DRS). The photocatalytic activity of the sample was evaluated by degradation of rhodamine B under visible light irradiation (λ > 420 nm), and the effect of BiPO4 content on the photocatalytic activity of the prepared materials was investigated. The main active species in the photocatalytic reaction were determined by capturing experiment, and the photocatalytic mechanism was proposed. The results showed that the optimum molar content of BiPO4 was 10%, and the optimal catalyst showed the best photocatalytic activity with the reaction rate constant of 0.14 min-1, which was about 3.7 times that of pure BiOBr. And it also exhibited amostly unchanged photocatalytic activity after three cycling experiments. The improvement of catalytic activity is mainly due to the formation of BiPO4/BiOBr heterojunction, which improves the separation efficiency of photo-generated carriers. In addition, the enhanced adsorption capacity of pollutants promotes the improvement of catalytic activity. The hole and superoxide radical are the main active species in the photocatalytic process, and the order of the role of the three species is hole > superoxide radical > hydroxyl radical.
2021, 37(10): 1839-1846
doi: 10.11862/CJIC.2021.214
Abstract:
BiVO4 photocatalytic materials with different Cu doping amounts were prepared by hydrothermal method at 180℃ via Cu(NO3)2·3H2O as the copper source, and exhibited enhanced photocatalytic performance under visible light. The samples were characterized and analyzed by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, UV-Vis absorption spectroscopy, photoluminescence spectra and electrochemical impedance spectroscopy. The photocatalytic activity of rhodamine B (RhB) dye was evaluated under the irradiation of 500 W Xe lamp to simulate the visible light. The results suggest that the Cu doping can not only alter the morphology of BiVO4, but also influence the photocatalytic activity of BiVO4. The visible light absorption of BiVO4 doped with mass ratio of 1% Cu was significantly enhanced in the range of 500~800 nm. This catalyst can achieve the optimum photocatalytic activity for the degradation of RhB (10 mg·L-1) with degradation rate of 81.6%, which was nearly 20% higher than that of pure BiVO4 prepared under the same conditions.
BiVO4 photocatalytic materials with different Cu doping amounts were prepared by hydrothermal method at 180℃ via Cu(NO3)2·3H2O as the copper source, and exhibited enhanced photocatalytic performance under visible light. The samples were characterized and analyzed by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, UV-Vis absorption spectroscopy, photoluminescence spectra and electrochemical impedance spectroscopy. The photocatalytic activity of rhodamine B (RhB) dye was evaluated under the irradiation of 500 W Xe lamp to simulate the visible light. The results suggest that the Cu doping can not only alter the morphology of BiVO4, but also influence the photocatalytic activity of BiVO4. The visible light absorption of BiVO4 doped with mass ratio of 1% Cu was significantly enhanced in the range of 500~800 nm. This catalyst can achieve the optimum photocatalytic activity for the degradation of RhB (10 mg·L-1) with degradation rate of 81.6%, which was nearly 20% higher than that of pure BiVO4 prepared under the same conditions.
2021, 37(10): 1847-1852
doi: 10.11862/CJIC.2021.212
Abstract:
A Fe(Ⅱ) complex[Fe(TPAPhen)3](BF4)2 was prepared by coordination reaction between Fe2+ ion and the ligand N-(4-(1-methyl-1H-imidazo[4, 5-f] [1,10]phenanthrolin-2-yl)phenyl)-N-phenylbenzenamine (TPAPhen), which was synthesized from the starting materials including 4-(diphenylamino)benzaldehyde and 1, 10-phenanthroline-5, 6- dione through condensation reaction and methylation. Then the electrochromic material poly-Fe(TPAPhen)3 was deposited on the ITO glass by electropolymerization of[Fe(TPAPhen)3](BF4)2. Poly-Fe(TPAPhen)3 exhibited multicolor change and good electrochromic performance under external voltage. Especially, a high optical contrast of 86% was achieved at 721 nm with a fast switch speed (coloration time: 2.6 s, bleaching time: 5.3 s) and high coloration efficiency of 971 cm2·C-1.
A Fe(Ⅱ) complex[Fe(TPAPhen)3](BF4)2 was prepared by coordination reaction between Fe2+ ion and the ligand N-(4-(1-methyl-1H-imidazo[4, 5-f] [1,10]phenanthrolin-2-yl)phenyl)-N-phenylbenzenamine (TPAPhen), which was synthesized from the starting materials including 4-(diphenylamino)benzaldehyde and 1, 10-phenanthroline-5, 6- dione through condensation reaction and methylation. Then the electrochromic material poly-Fe(TPAPhen)3 was deposited on the ITO glass by electropolymerization of[Fe(TPAPhen)3](BF4)2. Poly-Fe(TPAPhen)3 exhibited multicolor change and good electrochromic performance under external voltage. Especially, a high optical contrast of 86% was achieved at 721 nm with a fast switch speed (coloration time: 2.6 s, bleaching time: 5.3 s) and high coloration efficiency of 971 cm2·C-1.
2021, 37(10): 1853-1861
doi: 10.11862/CJIC.2021.221
Abstract:
Herein, the rare earth metal trifluoromethanesulfonate salts can function as new types of catalyst for the synthesis of covalent organic frameworks (COF), to accelerate the synthesis of four different types of COF (COF-42, TPB-DMTP, RT-COF-1, COF-LZU1) under ambient conditions and form desirable monodisperse COF nano-particles. Through the systematic optimization of the reaction conditions, the size of the COF particle was precisely controlled in a range of 200~900 nm. X-ray diffraction analysis showed that the resulting COF nano-particle exhibited good crystallinity. In addition, compared with the traditional method usually requiring high-temperature (120℃), this method is suitable for COF production at ambient temperature and pressure within half an hour.
Herein, the rare earth metal trifluoromethanesulfonate salts can function as new types of catalyst for the synthesis of covalent organic frameworks (COF), to accelerate the synthesis of four different types of COF (COF-42, TPB-DMTP, RT-COF-1, COF-LZU1) under ambient conditions and form desirable monodisperse COF nano-particles. Through the systematic optimization of the reaction conditions, the size of the COF particle was precisely controlled in a range of 200~900 nm. X-ray diffraction analysis showed that the resulting COF nano-particle exhibited good crystallinity. In addition, compared with the traditional method usually requiring high-temperature (120℃), this method is suitable for COF production at ambient temperature and pressure within half an hour.
2021, 37(10): 1862-1870
doi: 10.11862/CJIC.2021.205
Abstract:
Herein, Li2Ni2(MoO4)3@C composite with mass ratio of 23.7% of carbon was prepared using conventional solid-state method combined with mechanical ball milling and first investigated as the new anode of lithium-ion batteries. Compared with pure Li2Ni2(MoO4)3, Li2Ni2(MoO4)3@C presented an outstanding electrochemical performance, where a high reversible capacity of 845 mAh·g-1 can be acquired at a current density of 200 mA·g-1 after 50 cycles. It's worth noting that Li2Ni2(MoO4)3@C delivered high initial coulombic efficiency of 85%. Moreover, the lithium intercalation/de-intercalation behavior of Li2Ni2(MoO4)3@C was preliminarily investigated by cyclic voltammetry.
Herein, Li2Ni2(MoO4)3@C composite with mass ratio of 23.7% of carbon was prepared using conventional solid-state method combined with mechanical ball milling and first investigated as the new anode of lithium-ion batteries. Compared with pure Li2Ni2(MoO4)3, Li2Ni2(MoO4)3@C presented an outstanding electrochemical performance, where a high reversible capacity of 845 mAh·g-1 can be acquired at a current density of 200 mA·g-1 after 50 cycles. It's worth noting that Li2Ni2(MoO4)3@C delivered high initial coulombic efficiency of 85%. Moreover, the lithium intercalation/de-intercalation behavior of Li2Ni2(MoO4)3@C was preliminarily investigated by cyclic voltammetry.
2021, 37(10): 1871-1884
doi: 10.11862/CJIC.2021.204
Abstract:
Uniform erythrocyte-like Bi2WO6 was obtained by means of I- assisted tactic without utilizing any organic capping reagents in the convenient hydrothermal process for the first time. In order to analyze the preconditions which affect the morphology of Bi2WO6, we tried to change the I- concentration, hydrothermal time and temperature, then put forward a possible growth mechanism. I- absorb to the surface of Bi2WO6 nanoplates to prevent excessive accumulation of nanoplates and guide them to form an erythrocyte-like structure. The unique layered structure, on the one hand, increases the specific surface area and provides more reaction sites, on the other hand, it also enhances surface acidity and heightens the adsorption capacity.
Uniform erythrocyte-like Bi2WO6 was obtained by means of I- assisted tactic without utilizing any organic capping reagents in the convenient hydrothermal process for the first time. In order to analyze the preconditions which affect the morphology of Bi2WO6, we tried to change the I- concentration, hydrothermal time and temperature, then put forward a possible growth mechanism. I- absorb to the surface of Bi2WO6 nanoplates to prevent excessive accumulation of nanoplates and guide them to form an erythrocyte-like structure. The unique layered structure, on the one hand, increases the specific surface area and provides more reaction sites, on the other hand, it also enhances surface acidity and heightens the adsorption capacity.
2021, 37(10): 1885-1892
doi: 10.11862/CJIC.2021.179
Abstract:
To further improve the photocatalytic activity of polymeric semiconductor, graphitic carbon nitride (g-C3N4), for organic degradation, carbonized MoS2/S-doped g-C3N4 heterojunction (MoSC/S-CN) was prepared simply by hydrothermal method. And it was used to degrade rhodamine B (RhB) under visible-light illumination. Based on the results, it turned out that the visible-light adsorption range of optimized MoSC/S-CN became much broader, and the corresponding RhB degradation efficiency under visible-light illumination within 100 min was 92.5%, which was 68.83% higher than that of pure g-C3N4. Based on a series of structural and optical characterizations, it is clear that after S doping and further coupling with carbonized MoS2, MoSC/S-CN shows a synergistic effect. The band structure of g-C3N4 changes, and the photo-induced electron-hole pair separation rate is enhanced, which improves the photocatalytic activity of g-C3N4 effectively.
To further improve the photocatalytic activity of polymeric semiconductor, graphitic carbon nitride (g-C3N4), for organic degradation, carbonized MoS2/S-doped g-C3N4 heterojunction (MoSC/S-CN) was prepared simply by hydrothermal method. And it was used to degrade rhodamine B (RhB) under visible-light illumination. Based on the results, it turned out that the visible-light adsorption range of optimized MoSC/S-CN became much broader, and the corresponding RhB degradation efficiency under visible-light illumination within 100 min was 92.5%, which was 68.83% higher than that of pure g-C3N4. Based on a series of structural and optical characterizations, it is clear that after S doping and further coupling with carbonized MoS2, MoSC/S-CN shows a synergistic effect. The band structure of g-C3N4 changes, and the photo-induced electron-hole pair separation rate is enhanced, which improves the photocatalytic activity of g-C3N4 effectively.
2021, 37(10): 1893-1899
doi: 10.11862/CJIC.2021.203
Abstract:
A series of double perovskite Ca2Gd1-xTaO6: xTb3+ (CGTO: xTb3+) phosphors were prepared by a hightemperature solid-state reaction method. The X-ray diffraction, scanning electron microscopy, photoluminescence spectroscopy, decay curve and quantum efficiency (η) were used to characterize CGTO: xTb3+ phosphors. Under UV excitation, CGTO: xTb3+ phosphors show intense green light emission, which is originated from the characteristic 5D4-7F5 transition of the Tb3+ ion. On the basis of temperature-dependence luminescence spectra, the activation energy of thermal quenching was about 0.181 9 eV for CGTO: 0.15Tb3+ phosphor. CGTO: 0.15Tb3+ phosphor as optimum doping concentration exhibited intensive green emission with the η of 32.32% under 255 nm excitation.
A series of double perovskite Ca2Gd1-xTaO6: xTb3+ (CGTO: xTb3+) phosphors were prepared by a hightemperature solid-state reaction method. The X-ray diffraction, scanning electron microscopy, photoluminescence spectroscopy, decay curve and quantum efficiency (η) were used to characterize CGTO: xTb3+ phosphors. Under UV excitation, CGTO: xTb3+ phosphors show intense green light emission, which is originated from the characteristic 5D4-7F5 transition of the Tb3+ ion. On the basis of temperature-dependence luminescence spectra, the activation energy of thermal quenching was about 0.181 9 eV for CGTO: 0.15Tb3+ phosphor. CGTO: 0.15Tb3+ phosphor as optimum doping concentration exhibited intensive green emission with the η of 32.32% under 255 nm excitation.
2021, 37(10): 1900-1910
doi: 10.11862/CJIC.2021.208
Abstract:
Three Cu(Ⅱ)/Co(Ⅱ)/Ni(Ⅱ) coordination polymers, namely {[Cu2(μ5-deta)(2, 2'-bipy)2]·2H2O}n (1), [Co2(μ4-deta)(2, 2'-bipy)2(H2O)3]n(2) and {[Ni2(μ3-deta)(μ-4, 4'-bipy)2.5(H2O)5]·3H2O}n (3), have been constructed hydrothermally using H4deta (2, 3', 4, 4'-diphenyl ether tetracarboxylic acid), 2, 2'-bipy (2, 2'-bipyridine)/4, 4'-bipy (4, 4'-bipyridine) and CuCl2·2H2O, CoCl2·6H2O, NiCl2·6H2O, respectively, at 160℃. The products were isolated as stable crystalline solids and were characterized by IR spectra, elemental analyses, thermogravimetric analyses and single-crystal X-ray diffraction analyses. Single-crystal X-ray diffraction analyses reveal that the three compounds crystallize in the triclinic or monoclinic systems, space groups P1 or P21/n. Compound 1 discloses a 2D sheet. Compound 2 features a 1D chain structure. Compound 3 shows a 3D framework. The catalytic activity in the Knoevenagel condensation reaction of these compounds were investigated. Compound 1 exhibited an excellent catalytic activity in the Knoevenagel condensation reaction at room temperature.
Three Cu(Ⅱ)/Co(Ⅱ)/Ni(Ⅱ) coordination polymers, namely {[Cu2(μ5-deta)(2, 2'-bipy)2]·2H2O}n (1), [Co2(μ4-deta)(2, 2'-bipy)2(H2O)3]n(2) and {[Ni2(μ3-deta)(μ-4, 4'-bipy)2.5(H2O)5]·3H2O}n (3), have been constructed hydrothermally using H4deta (2, 3', 4, 4'-diphenyl ether tetracarboxylic acid), 2, 2'-bipy (2, 2'-bipyridine)/4, 4'-bipy (4, 4'-bipyridine) and CuCl2·2H2O, CoCl2·6H2O, NiCl2·6H2O, respectively, at 160℃. The products were isolated as stable crystalline solids and were characterized by IR spectra, elemental analyses, thermogravimetric analyses and single-crystal X-ray diffraction analyses. Single-crystal X-ray diffraction analyses reveal that the three compounds crystallize in the triclinic or monoclinic systems, space groups P1 or P21/n. Compound 1 discloses a 2D sheet. Compound 2 features a 1D chain structure. Compound 3 shows a 3D framework. The catalytic activity in the Knoevenagel condensation reaction of these compounds were investigated. Compound 1 exhibited an excellent catalytic activity in the Knoevenagel condensation reaction at room temperature.
