A new and facile co-modification by introducing oxygen vacancies and loading Ag nanoparticles to promote the photocatalytic activities of Bi 2 WO 6

Abstract(#br)A new and facile co-modification by introducing oxygen vacancies and loading Ag nanoparticles to largely promote the visible-light-driven photocatalytic activities of Bi 2 WO 6 semiconductor photocatalyst has been studied. Bi 2 WO 6 (BWO) flower-like micro-spheres were prepared by a hydrothermal method. Oxygen vacancies (OV) were introduced by a hydrogen reduction method and the concentration of OV was controlled by the heat treatment temperature under H 2 atmosphere. After OV modification, Ag nanoparticles were loaded on the BWO micro-sphere surface by a photo-reduction method and the Ag loaded content was controlled by the concentration of AgNO 3 solution. Results of visible-light-driven photocatalytic characterizations show that photocatalytic reaction rate constants of OV introduced modified type (BWO@OV) and Ag loaded modified type (BWO@Ag) increase by 1.47 and 1.67 times, respectively, comparing with BWO. Moreover, the reaction rate constant of co-modified type (OV@BWO@Ag) reaches as high as 2.53 times. Introducing OV into BWO enhances the separation of photo-generated electron/hole pairs, and the co-modification by both introducing OV and loading Ag nanoparticles has a synergy promotion effect on photocatalytic activity, which is believed to be a new technical route to enhance semiconductor photocatalytic properties