Optimizing the Electronic Structure of BiOBr Nanosheets via Combined Ba Doping and Oxygen Vacancies for Promoted Photocatalysis

The promotion of BiOBr via simultaneous alkaline earth metal (Ba) doping and massive oxygen vacancies (OVs) was for the first time investigated toward the photocatalytic removal of NO in air. The adsorption of NO and the generation of reactive oxygen species have been significantly enhanced with the synergistic effect of the Ba dopant and OVs, as evidenced by the highly combined experimental characterization and theoretical simulations, which is beneficial to optimizing the performance of photocatalytic NO removal. The removal rate on Ba-doped BiOBr with OVs is similar to 10 times higher than that on the pristine BiOBr after 30 min of visible-light irradiation. Significantly, in situ DRIFTS spectra and density functional theory calculations revealed that the NO+ intermediate forming on the Ba-doped BiOBr with OVs efficiently reduces the energy barrier and inhibits the generation of toxic byproducts, contributing to the optimization of the reaction process. The findings of this work go deep into the understanding of the synergistic effect of alkaline earth metal doping and OVs for elevating the photocatalysis efficiency.