In this work,a novel Z-scheme Bi_(5)O_(7-δ)I/CeO_(2-δ)heterojunction photocatalyst was prepared by combining hydrothermal synthesis and thermal treatment methods.Oxygen vacancies were in situ generated on the surfac...In this work,a novel Z-scheme Bi_(5)O_(7-δ)I/CeO_(2-δ)heterojunction photocatalyst was prepared by combining hydrothermal synthesis and thermal treatment methods.Oxygen vacancies were in situ generated on the surface of Bi_(5)O_(7-δ)I and CeO_(2-δ)nanostructures.The existence of oxygen vacancies significantly improved the light absorption of CeO_(2-δ)and inhibited the recombination of photogenerated carriers.Based on the photocatalytic activity,the as-prepared Bi_(5)O_(7-δ)I/CeO_(2-δ)photocatalyst exhibited excellent photocatalytic NO removal performance under visible light irradiation.The results of the capture experiment and electron spin resonance(ESR)spectroscopy show that super oxygen radicals(·O_(2)^(-))and hydroxyl radicals(·OH)are the main active species in the overall photocatalytic reaction process.Density functional theory(DFT)calculations and ESR results demonstrate that a Z-scheme heterojunction is formed between Bi_(5)O_(7-δ)I and CeO_(2-δ).Compared with the traditional type-Ⅱ heterojunction,the Z-scheme heterojunction exhibited more efficient charge separation and robust redox capacity in the photocatalytic reaction.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51772183 and 52072230)the Fundamental Research Funds for the Central Universities(2020TS028).
文摘In this work,a novel Z-scheme Bi_(5)O_(7-δ)I/CeO_(2-δ)heterojunction photocatalyst was prepared by combining hydrothermal synthesis and thermal treatment methods.Oxygen vacancies were in situ generated on the surface of Bi_(5)O_(7-δ)I and CeO_(2-δ)nanostructures.The existence of oxygen vacancies significantly improved the light absorption of CeO_(2-δ)and inhibited the recombination of photogenerated carriers.Based on the photocatalytic activity,the as-prepared Bi_(5)O_(7-δ)I/CeO_(2-δ)photocatalyst exhibited excellent photocatalytic NO removal performance under visible light irradiation.The results of the capture experiment and electron spin resonance(ESR)spectroscopy show that super oxygen radicals(·O_(2)^(-))and hydroxyl radicals(·OH)are the main active species in the overall photocatalytic reaction process.Density functional theory(DFT)calculations and ESR results demonstrate that a Z-scheme heterojunction is formed between Bi_(5)O_(7-δ)I and CeO_(2-δ).Compared with the traditional type-Ⅱ heterojunction,the Z-scheme heterojunction exhibited more efficient charge separation and robust redox capacity in the photocatalytic reaction.
