The appropriate energy level position of photocatalysts dominates the photocatalytic redox reaction and utilization efficiency of solar energy for wastewater treatment.Herein,we report a near-infrared(NIR)light driven...The appropriate energy level position of photocatalysts dominates the photocatalytic redox reaction and utilization efficiency of solar energy for wastewater treatment.Herein,we report a near-infrared(NIR)light driven Bi^(5+)-rich Bi407 photocatalyst,achieving a greatly enhanced photocatalytic activity for pollutant removal compared with Bi3+-replenished Bi2O3.Density functional theory calculations show the formation of an intermediate band in the Bi_(4)O_(7)structure because of the hybridization of O 2p and Bi 4s orbits.The formation of the intermediate band not only narrows the band gap but also improves the optical absorption property and separation efficiency of the photoinduced carriers.The existence of the oxygen vacancies(OVs)in the Bi_(4)O_(7)nanosheets ensures high carriers’concentration,which is verified by the Hall effect test.The synergetic effects of the OVs and Bi^(5+)greatly accelerate the separation efficiency of the photogenerated carriers.Consequently,the Bi_(4)O_(7)nanosheets exhibit enhanced NIR light driven photocatalytic activity for the degradation of rhodamine B and ciprofloxacin compared with the bulk Bi2O3.This study paves the way to the design of highly efficient NIR light-responsive Bi-based photocatalysts for environmental purification.展开更多
基金supported by the National Natural Science Foundation of China(No.21806194)the Outstanding Talent Research Fund of Zhengzhou University(No.32340099)the Nanyang Environment and Water Research Institute(Core Fund),Nanyang Technological University,Singapore。
文摘The appropriate energy level position of photocatalysts dominates the photocatalytic redox reaction and utilization efficiency of solar energy for wastewater treatment.Herein,we report a near-infrared(NIR)light driven Bi^(5+)-rich Bi407 photocatalyst,achieving a greatly enhanced photocatalytic activity for pollutant removal compared with Bi3+-replenished Bi2O3.Density functional theory calculations show the formation of an intermediate band in the Bi_(4)O_(7)structure because of the hybridization of O 2p and Bi 4s orbits.The formation of the intermediate band not only narrows the band gap but also improves the optical absorption property and separation efficiency of the photoinduced carriers.The existence of the oxygen vacancies(OVs)in the Bi_(4)O_(7)nanosheets ensures high carriers’concentration,which is verified by the Hall effect test.The synergetic effects of the OVs and Bi^(5+)greatly accelerate the separation efficiency of the photogenerated carriers.Consequently,the Bi_(4)O_(7)nanosheets exhibit enhanced NIR light driven photocatalytic activity for the degradation of rhodamine B and ciprofloxacin compared with the bulk Bi2O3.This study paves the way to the design of highly efficient NIR light-responsive Bi-based photocatalysts for environmental purification.
