| Affiliation: | 1. College of Optoelectronic Engineering, Chongqing University of Posts and Telecommunications, Chongqing, 400065 China;2. School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001 China;3. State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023 China;4. Key Laboratory of Optoelectronic Technology & Systems (Ministry of Education), College of Optoelectronic Engineering, Chongqing University, Chongqing, 400044 China;5. Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 314000 China;6. Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 314000 China State Key Laboratory of High Field Laser Physics and CAS Center for Excellence in Ultra-Intense Laser Science, Shanghai Institute of Optics and Fine Mechanics, CAS, Shanghai, 201800 China;7. State Key Laboratory of High Field Laser Physics and CAS Center for Excellence in Ultra-Intense Laser Science, Shanghai Institute of Optics and Fine Mechanics, CAS, Shanghai, 201800 China |
| Abstract: | In this study, a new type of lead-free double perovskite Cs2TeBr6 combined with metal-free semiconductor g-C3N4 heterojunction is constructed and used for photocatalytic CO2 reduction for the first time. The S-scheme charge transfer mechanism between Cs2TeBr6 and g-C3N4 is systematically verified by X-ray photoelectron spectroscopy (XPS), electron spin resonance (ESR) and in situ Fourier infrared spectroscopy(FT-IR). The formation of S-type heterojunction makes the photocatalyst have higher charge separation ability and highest redox ability. The results show that 5%-CTB/CN heterojunction material has the best photocatalytic reduction effect on CO2 under visible light irradiation. After 3 h of illumination, the yield of CO and CH4 are 468.9 µmol g−1 and 61.31 µmol g−1, respectively. The yield of CO is 1.5 times and 32 times that of pure Cs2TeBr6 and g-C3N4, and the yield of CH4 is doubled compared with pure Cs2TeBr6. However, g-C3N4 almost does not produce CH4, which indicates that the construction of heterojunction helps to further improve the photocatalytic performance of the material. This study provides a new idea for the preparation of Cs2TeBr6/g-C3N4 heterojunction and its effective interfacial charge separation. |
