Theoretical insights into nitrogen oxide activation on halogen defect-rich{001}facets of bismuth oxyhalide

摘要

Surface vacancies,serving as the activation centers for surface-adsorbed species,have been widely applied in catalysts to improve their activity and selectivity.In the case of ternary compound semiconductors,there is some controversy about exposed atoms and surface defects.Two-dimensional layered BiOCl is an important photocatalyst,which has had numerous studies focused on its oxygen vacancy(O_V)and bismuth vacancy(Bi_V).It has been realized that its(001)surface can consist of exposed halogen atoms rather than oxygen atoms,which thus needs a new explanation for its surface defect engineering mechanism.Using first-principles calculations,the activation behavior of NO_X(NO_(2),NO,N_(2)O)at a chlorine vacancy(Cl_V)on the BiOCl(001)surface is systematically studied.It is found that after introducing Cl_V on BiOCl(001)surfaces,NO_X molecules all show excellent activities with longer chemical bonds by capturing electrons from the catalyst.Our work furnishes fundamental insight into the activation of small molecules on defect-rich surfaces of ternary compound catalysts.