In this study, the Ag/Ag Cl/WO3 plasmonic Z-scheme photocatalysts with different contents of Ag/Ag Cl nanoparticles（NPs） were prepared through a facile ultrasonic precipitation method in geothermal water,wherein the...In this study, the Ag/Ag Cl/WO3 plasmonic Z-scheme photocatalysts with different contents of Ag/Ag Cl nanoparticles（NPs） were prepared through a facile ultrasonic precipitation method in geothermal water,wherein the geothermal water served as the chlorine source. Then the photocatalytic activity was investigated by degradation of 4-Aminobenzoic acid（4-ABA） under visible-light irradiation. It was found that the as-prepared 50 wt% Ag/Ag Cl/WO3 photocatalyst showed the highest photocatalytic efficiency with 25.12 and 3.53 times higher than those of pure WO3 and Ag/Ag Cl, respectively. The active species trapping experiments indicated that h＋and ·O2-were key factors in 4-ABA photodegradation process. The possible plasmonic Z-scheme photocatalytic mechanism of photocatalytic reaction for 4-ABA degradation was proposed based on systematical characterizations. We hope this paper could give new ideas for further exploiting geothermal energy to design and fabricate highly efficient visible-light-driven photocatalysts for environmental remediation.展开更多
采用微波辅助合成方法将WO3固载到金属有机骨架MIL-101(Cr)上,借助于沉积沉淀–光还原方法将Ag/AgCl和WO3/MIL-101复合在一起,制备出Ag/AgCl@WO3/MIL-101可见光催化剂。利用FT-IR、XRD、UV-Vis-DRS和XPS测试技术对该催化剂进行了表征。...采用微波辅助合成方法将WO3固载到金属有机骨架MIL-101(Cr)上,借助于沉积沉淀–光还原方法将Ag/AgCl和WO3/MIL-101复合在一起,制备出Ag/AgCl@WO3/MIL-101可见光催化剂。利用FT-IR、XRD、UV-Vis-DRS和XPS测试技术对该催化剂进行了表征。结果表明,Ag/AgCl和WO3的引入没有改变MIL-101的结构,催化剂在可见光区有强烈的光吸收。当WO3的负载量为0.3(w)%,Ag的负载量为3.4(w)%时,Ag/AgCl@WO3/MIL-101对70 mL 20 mg/L的罗丹明B溶液的降解率达到100%,并且该催化剂具有较好的稳定性。展开更多
WO_3是一种带隙约为2.7 e V的过渡金属半导体,可见光就能激发其光催化活性,这极大地提高了太阳光的利用率,但纯WO_3纳米材料催化活性偏低,针对这一难题,本文选取了三维网格结构的WO_3纳米材料为载体,利用化学搅拌法制备了不同摩尔比的Ag...WO_3是一种带隙约为2.7 e V的过渡金属半导体,可见光就能激发其光催化活性,这极大地提高了太阳光的利用率,但纯WO_3纳米材料催化活性偏低,针对这一难题,本文选取了三维网格结构的WO_3纳米材料为载体,利用化学搅拌法制备了不同摩尔比的Ag_2O/WO_3复合光催化剂。选择亚甲基蓝为研究对象,测定了不同摩尔比的Ag_2O/WO_3复合催化剂的光催化性能。实验表明,当Ag_2O和WO_3的摩尔配比为1∶2时,该复合催化剂的光催性能最好。过量的Ag_2O纳米颗粒会增加Ag_2O/WO_3内部电子空穴的复合几率,反而导致光催化剂反应活性的降低。展开更多
The ternary plasmonic Ag Cl/Ag/g-C_3N_4 photocatalysts were successfully fabricated by a modified deposition–precipitation method, through which Ag/Ag Cl nanoparticles(5–15 nm in size) were evenly dispersed on the s...The ternary plasmonic Ag Cl/Ag/g-C_3N_4 photocatalysts were successfully fabricated by a modified deposition–precipitation method, through which Ag/Ag Cl nanoparticles(5–15 nm in size) were evenly dispersed on the surface of g-C_3N_4. The Ag Cl/Ag/g-C_3N_4 composites exhibited higher photocatalytic activity than Ag/Ag Cl and g-C_3N_4. The enhanced photocatalytic performance could be attributed to an efficient separation of electron–hole pairs through a Z-scheme mechanism, in which Ag nanoparticles acted as charge separation centers.展开更多
Core–shell nanoparticles containing plasmonic metals（Ag or Au） have been frequently reported to enhance performance of photo-electrochemical（PEC） devices. However, the stability of these particles in water-splitt...Core–shell nanoparticles containing plasmonic metals（Ag or Au） have been frequently reported to enhance performance of photo-electrochemical（PEC） devices. However, the stability of these particles in water-splitting conditions is usually not addressed. In this study we demonstrate that Ag@SiOcore–shell particles are instable in the acidic conditions in which WO-based PEC cells typically operate, Ag in the core being prone to oxidation, even if the SiOshell has a thickness in the order of 10 nm. This is evident from in situ voltammetry studies of several anode composites. Similar to the results of the PEC experiments, the Ag@SiOcore–shell particles are instable in slurry-based, Pt/ZnO induced photocatalytic water-splitting. This was evidenced by in situ photodeposition of Ag nanoparticles on the Pt-loaded ZnO catalyst, observed in TEM micrographs obtained after reaction. We explain the instability of Ag@SiOby OH-radical induced oxidation of Ag, yielding dissolved Ag+. Our results imply that a decrease in shell permeability for OH-radicals is necessary to obtain stable, Ag-based plasmonic entities in photo-electrochemical and photocatalytic water splitting.展开更多
基金the financial support by the National Natural Science Foundation of China (grant no. 51272107 and 51372118)the Doctor Discipline Special Research Foundation of Chinese Ministry of Education (grant no. 20133219110015)
文摘In this study, the Ag/Ag Cl/WO3 plasmonic Z-scheme photocatalysts with different contents of Ag/Ag Cl nanoparticles（NPs） were prepared through a facile ultrasonic precipitation method in geothermal water,wherein the geothermal water served as the chlorine source. Then the photocatalytic activity was investigated by degradation of 4-Aminobenzoic acid（4-ABA） under visible-light irradiation. It was found that the as-prepared 50 wt% Ag/Ag Cl/WO3 photocatalyst showed the highest photocatalytic efficiency with 25.12 and 3.53 times higher than those of pure WO3 and Ag/Ag Cl, respectively. The active species trapping experiments indicated that h＋and ·O2-were key factors in 4-ABA photodegradation process. The possible plasmonic Z-scheme photocatalytic mechanism of photocatalytic reaction for 4-ABA degradation was proposed based on systematical characterizations. We hope this paper could give new ideas for further exploiting geothermal energy to design and fabricate highly efficient visible-light-driven photocatalysts for environmental remediation.
文摘采用微波辅助合成方法将WO3固载到金属有机骨架MIL-101(Cr)上,借助于沉积沉淀–光还原方法将Ag/AgCl和WO3/MIL-101复合在一起,制备出Ag/AgCl@WO3/MIL-101可见光催化剂。利用FT-IR、XRD、UV-Vis-DRS和XPS测试技术对该催化剂进行了表征。结果表明,Ag/AgCl和WO3的引入没有改变MIL-101的结构,催化剂在可见光区有强烈的光吸收。当WO3的负载量为0.3(w)%,Ag的负载量为3.4(w)%时,Ag/AgCl@WO3/MIL-101对70 mL 20 mg/L的罗丹明B溶液的降解率达到100%,并且该催化剂具有较好的稳定性。
文摘WO_3是一种带隙约为2.7 e V的过渡金属半导体,可见光就能激发其光催化活性,这极大地提高了太阳光的利用率,但纯WO_3纳米材料催化活性偏低,针对这一难题,本文选取了三维网格结构的WO_3纳米材料为载体,利用化学搅拌法制备了不同摩尔比的Ag_2O/WO_3复合光催化剂。选择亚甲基蓝为研究对象,测定了不同摩尔比的Ag_2O/WO_3复合催化剂的光催化性能。实验表明,当Ag_2O和WO_3的摩尔配比为1∶2时,该复合催化剂的光催性能最好。过量的Ag_2O纳米颗粒会增加Ag_2O/WO_3内部电子空穴的复合几率,反而导致光催化剂反应活性的降低。
基金supported by the National Natural Science Foundation of China(51572103 and 51502106)the Distinguished Young Scholar of Anhui Province(1808085J14)+2 种基金the Foundation for Young Talents in College of Anhui Province(gxyqZD2017051)the Key Foundation of Educational Commission of Anhui Province(KJ2016SD53)the Innovation Team of Design and Application of Advanced Energetic Materials(KJ2015TD003)~~
基金financial aid from the National Natural Science Foundation of China(NSFC No.51472133)
文摘The ternary plasmonic Ag Cl/Ag/g-C_3N_4 photocatalysts were successfully fabricated by a modified deposition–precipitation method, through which Ag/Ag Cl nanoparticles(5–15 nm in size) were evenly dispersed on the surface of g-C_3N_4. The Ag Cl/Ag/g-C_3N_4 composites exhibited higher photocatalytic activity than Ag/Ag Cl and g-C_3N_4. The enhanced photocatalytic performance could be attributed to an efficient separation of electron–hole pairs through a Z-scheme mechanism, in which Ag nanoparticles acted as charge separation centers.
基金part of the research programme of the Foundation for Fundamental Research on Matter(FOM,project 10TBSC07-1),which is part of the Netherlands Organisation for Scientific Research(NWO)
文摘Core–shell nanoparticles containing plasmonic metals（Ag or Au） have been frequently reported to enhance performance of photo-electrochemical（PEC） devices. However, the stability of these particles in water-splitting conditions is usually not addressed. In this study we demonstrate that Ag@SiOcore–shell particles are instable in the acidic conditions in which WO-based PEC cells typically operate, Ag in the core being prone to oxidation, even if the SiOshell has a thickness in the order of 10 nm. This is evident from in situ voltammetry studies of several anode composites. Similar to the results of the PEC experiments, the Ag@SiOcore–shell particles are instable in slurry-based, Pt/ZnO induced photocatalytic water-splitting. This was evidenced by in situ photodeposition of Ag nanoparticles on the Pt-loaded ZnO catalyst, observed in TEM micrographs obtained after reaction. We explain the instability of Ag@SiOby OH-radical induced oxidation of Ag, yielding dissolved Ag+. Our results imply that a decrease in shell permeability for OH-radicals is necessary to obtain stable, Ag-based plasmonic entities in photo-electrochemical and photocatalytic water splitting.
