以Bi(NO3)3·5H2O、Na2WO4·2H2O、AgNO3为原料,利用液相沉淀法制备Bi2WO6及Ag掺杂Bi2WO6光催化剂,以亚甲基蓝溶液为目标降解物,对其降解效率进行研究。研究结果表明,当亚甲基蓝溶液的浓度为15 mg/L,体积为50 m L,降解时间3.5 h...以Bi(NO3)3·5H2O、Na2WO4·2H2O、AgNO3为原料,利用液相沉淀法制备Bi2WO6及Ag掺杂Bi2WO6光催化剂,以亚甲基蓝溶液为目标降解物,对其降解效率进行研究。研究结果表明,当亚甲基蓝溶液的浓度为15 mg/L,体积为50 m L,降解时间3.5 h,Bi2WO6降解率仅为55%;当Ag/Bi摩尔比为0.4%时,Ag/Bi2WO6表现出较好的催化性能,相同时间降解率达到97%。展开更多
Ag3PO4has good potential for use in photocatalytic degradation of organic contaminants.However,the activity and stability of Ag3PO4is hard to sustain because of photocorrosion and the positive potential of the conduct...Ag3PO4has good potential for use in photocatalytic degradation of organic contaminants.However,the activity and stability of Ag3PO4is hard to sustain because of photocorrosion and the positive potential of the conduction band of Ag3PO4.In this study,A composite consisting of Bi2WO6nanosheets and Ag3PO4was developed to curb recombination of charge carriers and enhance the activity and stability of the catalyst.Formation of a Ag3PO4/Bi2WO6composite was confirmed using X‐ray diffraction,energy‐dispersive X‐ray spectroscopy,and X‐ray photoelectron spectroscopy.Photoluminescence spectroscopy provided convincing evidence that compositing Bi2WO6with Ag3PO4effectively reduced photocorrosion of Ag3PO4.The Ag3PO4/Bi2WO6composite gave a high photocatalytic performance in photodegradation of methylene blue.A degradation rate of0.61min?1was achieved;this is1.3and6.0times higher than those achieved using Ag3PO4(0.47min?1)and Bi2WO6(0.10min?1),respectively.Reactive species trapping experiments using the Ag3PO4/Bi2WO6composite showed that holes,?OH,and?O2?all played specific roles in the photodegradation process.The photocatalytic mechanism was investigated and a Z‐scheme was proposed as a plausible mechanism.展开更多
Highly crystalline orthorhombic Bi2WO6 powders were hydrothermally synthesized from aqueous solutions of Na2WO4 · 2H2O and Bi （NO3）3 · 5H2O over a wide range of pH. The effect of pH on morphologies, sizes ...Highly crystalline orthorhombic Bi2WO6 powders were hydrothermally synthesized from aqueous solutions of Na2WO4 · 2H2O and Bi （NO3）3 · 5H2O over a wide range of pH. The effect of pH on morphologies, sizes and properties of the Bi2WO6 crystals was investigated. The band gaps of the as-prepared Bi2WO6 were determined from the onset of the absorption edge of UV-vis diffuse reflectance spectra. The methyl orange photodegradation was employed as a probe reaction to test the photocatalytic activity of the as-prepared samples under visible light irradiation. The photocatalytic activities of methyl orange degradation under visible light irradiation are strongly dependent on the pH used in the synthesis. The highest efficiency is observed at pH=7.展开更多
Hierarchical Ag/Bi2WO6 nanomaterials were prepared by a facile one-step hydrothermal method in mixed acetic acid and ethylene glycol (EG) medium. EG is employed as mild reducing agent for the formation of metallic Ag ...Hierarchical Ag/Bi2WO6 nanomaterials were prepared by a facile one-step hydrothermal method in mixed acetic acid and ethylene glycol (EG) medium. EG is employed as mild reducing agent for the formation of metallic Ag from Ag+ precursors. In situ energy dispersive X-ray diffraction (EDXRD) monitoring showed that the hydrothermal formation kinetics of Bi2WO6 in the presence of EG was significantly slowed down due to its very high viscosity. The photocatalytic activities of Ag/Bi2WO6 composites were evaluated by the photodegradation of methylene blue (MB) under visible light irradiation. The photocatalytic activity of Bi2WO6 is strongly influenced by the Ag loading. The enhanced catalytic activity of the composites is based on the cooperative effects of plasmon absorption band and separation of photogenerated electron-hole pairs.展开更多
文摘以Bi(NO3)3·5H2O、Na2WO4·2H2O、AgNO3为原料,利用液相沉淀法制备Bi2WO6及Ag掺杂Bi2WO6光催化剂,以亚甲基蓝溶液为目标降解物,对其降解效率进行研究。研究结果表明,当亚甲基蓝溶液的浓度为15 mg/L,体积为50 m L,降解时间3.5 h,Bi2WO6降解率仅为55%;当Ag/Bi摩尔比为0.4%时,Ag/Bi2WO6表现出较好的催化性能,相同时间降解率达到97%。
基金supported by the National Natural Science Foundation of China(51572103,51502106)the Foundation for Young Talents in College of Anhui Province(gxyqZD201751)~~
文摘Ag3PO4has good potential for use in photocatalytic degradation of organic contaminants.However,the activity and stability of Ag3PO4is hard to sustain because of photocorrosion and the positive potential of the conduction band of Ag3PO4.In this study,A composite consisting of Bi2WO6nanosheets and Ag3PO4was developed to curb recombination of charge carriers and enhance the activity and stability of the catalyst.Formation of a Ag3PO4/Bi2WO6composite was confirmed using X‐ray diffraction,energy‐dispersive X‐ray spectroscopy,and X‐ray photoelectron spectroscopy.Photoluminescence spectroscopy provided convincing evidence that compositing Bi2WO6with Ag3PO4effectively reduced photocorrosion of Ag3PO4.The Ag3PO4/Bi2WO6composite gave a high photocatalytic performance in photodegradation of methylene blue.A degradation rate of0.61min?1was achieved;this is1.3and6.0times higher than those achieved using Ag3PO4(0.47min?1)and Bi2WO6(0.10min?1),respectively.Reactive species trapping experiments using the Ag3PO4/Bi2WO6composite showed that holes,?OH,and?O2?all played specific roles in the photodegradation process.The photocatalytic mechanism was investigated and a Z‐scheme was proposed as a plausible mechanism.
基金Funded by the PCSIRT, the National Natural Science Foundation of China (Nos. 50532030 and 50625206)the Zhejiang Provincial Natural Science Foundation of China (No. Z4080021)
文摘Highly crystalline orthorhombic Bi2WO6 powders were hydrothermally synthesized from aqueous solutions of Na2WO4 · 2H2O and Bi （NO3）3 · 5H2O over a wide range of pH. The effect of pH on morphologies, sizes and properties of the Bi2WO6 crystals was investigated. The band gaps of the as-prepared Bi2WO6 were determined from the onset of the absorption edge of UV-vis diffuse reflectance spectra. The methyl orange photodegradation was employed as a probe reaction to test the photocatalytic activity of the as-prepared samples under visible light irradiation. The photocatalytic activities of methyl orange degradation under visible light irradiation are strongly dependent on the pH used in the synthesis. The highest efficiency is observed at pH=7.
基金supported by the National Natural Science Foundation of China (51102245 and U1232119)the Innovative Research Team of Southwest Petroleum University (2012XJZT002)the Swiss National Science Foundation (SNSF Professorship PP0P2-133483/1)
文摘Hierarchical Ag/Bi2WO6 nanomaterials were prepared by a facile one-step hydrothermal method in mixed acetic acid and ethylene glycol (EG) medium. EG is employed as mild reducing agent for the formation of metallic Ag from Ag+ precursors. In situ energy dispersive X-ray diffraction (EDXRD) monitoring showed that the hydrothermal formation kinetics of Bi2WO6 in the presence of EG was significantly slowed down due to its very high viscosity. The photocatalytic activities of Ag/Bi2WO6 composites were evaluated by the photodegradation of methylene blue (MB) under visible light irradiation. The photocatalytic activity of Bi2WO6 is strongly influenced by the Ag loading. The enhanced catalytic activity of the composites is based on the cooperative effects of plasmon absorption band and separation of photogenerated electron-hole pairs.
