Defect engineering has been regarded as a versatile strategy to maneuver the photocatalytic activity.However,there are a few studies concerning how to maintain the stability of defects,which is important to ensure sus...Defect engineering has been regarded as a versatile strategy to maneuver the photocatalytic activity.However,there are a few studies concerning how to maintain the stability of defects,which is important to ensure sustainable photocatalytic performance.Here,a novel strategy to modulate the structural properties of BiSbO_(4)using light-induced dynamic oxygen vacancies is reported by us for efficient and stable photocatalytic oxidation of formaldehyde.Interestingly,the continuous consumption and replenishment of vacancies(namely dynamic vacancies)ensure the dynamic stability of oxygen vacancies,thus guaranteeing the excellent photocatalytic stability.The oxygen vacancies could also accelerate the electron migration,inhibit the photogenerated electron/hole recombination,widen the light absorption spectra,and thus improve the photocatalytic formaldehyde removal performance.Combined with the results of in situ DRIFTS,the reaction mechanism for each step of formaldehyde oxidation is revealed.As supported by DFT calculation of Gibbs free energy,the introduction of oxygen vacancies into BiSbO_(4)can promote spontaneous process of formaldehyde oxidation.Our work highlights a promising approach for stabilizing the defects and proposes the photocatalytic reaction mechanism in combination with the thermodynamic functions.展开更多
One of the core issues in the photocatalytic oxidation of nitric oxide is the effective co nversion of NO into the final product(nitrate).More than just improving the visible light photocatalytic performance of BiOCl,...One of the core issues in the photocatalytic oxidation of nitric oxide is the effective co nversion of NO into the final product(nitrate).More than just improving the visible light photocatalytic performance of BiOCl,we aim to inhibit the generation of toxic by-product NO_(2) during this process.In this study,we demonstrate that the oxygen vacancies(OVs)modulate its surface photogene rated carrier transfer to inflect the NO conversion pathway by a facile mixed solvent method to induce OVs on the surface of BiOCl.The photocatalytic NO removal efficiency under visible light increased from 5.6%to 36.4%.In addition,the production rate of NO_(2) is effectively controlled.The effects of OVs on the generation of reactive oxygen species,electronic transfer,optical properties,and photocatalytic NO oxidation are investigated by combining density functional theory(DFT)theoretical calculations,the in situ FTIR spectra and experimental characterization.The OVs on the surface of BiOCl speed the trapping and transfer of localized electrons to activate the O_(2),producing O_(2)·,which avoid NO_(2) formation,resulting in complete oxidation of NO(NO+O_(2)·→NO_(3)).These findings can serve as the basis for controlling and blocking the generation of highly toxic intermediates through regulating the reactive species during the NO oxidation.It also can help us to understand the role of OV on the BiOCl surface and application of photocatalytic technology for safe air purification.展开更多
With the acceleration of the urban industrialization process,air pollutant emission has increased sharply,which seriously endangers the ecological environment and human beings.Solar-driven photocatalysis has the broad...With the acceleration of the urban industrialization process,air pollutant emission has increased sharply,which seriously endangers the ecological environment and human beings.Solar-driven photocatalysis has the broad-spectrum activity for various inorganic to organic pollutants at ambient temperature without harsh reaction conditions,which shows a very broad application prospect in air purification.However,the photocatalysis technology suffers from the unrevealed reaction me-chanism and the deactivation of photocatalysts,which severely limits its practical application.Currently,there is still a huge gap between basic research and industrial application in the field of photocatalytic air purification.This review summarizes recent progress on photocatalytic degradation of air pollutants and categorizes them based on the types of photocatalytic materials and air pollutants,with a focus on photocatalytic reaction mechanisms and the application scenarios of photocatalytic air purification to identify this gap.We also critically discussed the major challenges for promoting applications of photo-catalytic technology and put forward the development prospect.展开更多
基金supported by the National Natural Science Foundation of China (21822601, 21777011, and 21501016)the Innovative Research Team of Chongqing (CXQT19023)
文摘Defect engineering has been regarded as a versatile strategy to maneuver the photocatalytic activity.However,there are a few studies concerning how to maintain the stability of defects,which is important to ensure sustainable photocatalytic performance.Here,a novel strategy to modulate the structural properties of BiSbO_(4)using light-induced dynamic oxygen vacancies is reported by us for efficient and stable photocatalytic oxidation of formaldehyde.Interestingly,the continuous consumption and replenishment of vacancies(namely dynamic vacancies)ensure the dynamic stability of oxygen vacancies,thus guaranteeing the excellent photocatalytic stability.The oxygen vacancies could also accelerate the electron migration,inhibit the photogenerated electron/hole recombination,widen the light absorption spectra,and thus improve the photocatalytic formaldehyde removal performance.Combined with the results of in situ DRIFTS,the reaction mechanism for each step of formaldehyde oxidation is revealed.As supported by DFT calculation of Gibbs free energy,the introduction of oxygen vacancies into BiSbO_(4)can promote spontaneous process of formaldehyde oxidation.Our work highlights a promising approach for stabilizing the defects and proposes the photocatalytic reaction mechanism in combination with the thermodynamic functions.
基金the National Natural Science Foundation of China(51508356)Science and Technology Support Program of Sichuan Province(2014GZ0213,2016GZ0045)Youth Project in Science and Technology Innovation Program of Sichuan Province(17-YCG053)~~
基金the National Natural Science Foundation of China(Nos.21822601,21777011 and 21501016)the Plan for"National Youth Talents"of the Organization Department of the Central Committee。
文摘One of the core issues in the photocatalytic oxidation of nitric oxide is the effective co nversion of NO into the final product(nitrate).More than just improving the visible light photocatalytic performance of BiOCl,we aim to inhibit the generation of toxic by-product NO_(2) during this process.In this study,we demonstrate that the oxygen vacancies(OVs)modulate its surface photogene rated carrier transfer to inflect the NO conversion pathway by a facile mixed solvent method to induce OVs on the surface of BiOCl.The photocatalytic NO removal efficiency under visible light increased from 5.6%to 36.4%.In addition,the production rate of NO_(2) is effectively controlled.The effects of OVs on the generation of reactive oxygen species,electronic transfer,optical properties,and photocatalytic NO oxidation are investigated by combining density functional theory(DFT)theoretical calculations,the in situ FTIR spectra and experimental characterization.The OVs on the surface of BiOCl speed the trapping and transfer of localized electrons to activate the O_(2),producing O_(2)·,which avoid NO_(2) formation,resulting in complete oxidation of NO(NO+O_(2)·→NO_(3)).These findings can serve as the basis for controlling and blocking the generation of highly toxic intermediates through regulating the reactive species during the NO oxidation.It also can help us to understand the role of OV on the BiOCl surface and application of photocatalytic technology for safe air purification.
基金supported by the National Natural Science Foundation of China(22176029,21822601)the Excellent Youth Foundation of Sichuan Province in China(2021JDJQ0006).
文摘With the acceleration of the urban industrialization process,air pollutant emission has increased sharply,which seriously endangers the ecological environment and human beings.Solar-driven photocatalysis has the broad-spectrum activity for various inorganic to organic pollutants at ambient temperature without harsh reaction conditions,which shows a very broad application prospect in air purification.However,the photocatalysis technology suffers from the unrevealed reaction me-chanism and the deactivation of photocatalysts,which severely limits its practical application.Currently,there is still a huge gap between basic research and industrial application in the field of photocatalytic air purification.This review summarizes recent progress on photocatalytic degradation of air pollutants and categorizes them based on the types of photocatalytic materials and air pollutants,with a focus on photocatalytic reaction mechanisms and the application scenarios of photocatalytic air purification to identify this gap.We also critically discussed the major challenges for promoting applications of photo-catalytic technology and put forward the development prospect.
