Oxygen vacancies on the BiOCl surface promoted photocatalytic complete NO oxidation via superoxide radicals

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;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;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;,producing O_;,which avoid NO;formation,resulting in complete oxidation of NO（NO+O;→NO;）.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.