Dramatically enhanced photocatalytic properties of Ag-modified graphene–ZnO quasi-shell–core heterojunction composite material

Abstract

Preparation of semiconductor heterojunction composites with special nanostructure is an effective way to enhance the photoelectric conversion efficiency of photocatalysts. In this work, the graphene–ZnO composite with quasi-shell–core structure was successfully prepared using a one-step wet chemical method. Silver nanoparticles are loaded onto the graphene–ZnO quasi-shell–core composite by photo-assisted reduction. Ag modification significantly improved the photocatalytic rhodamine B degradation capability of the graphene–ZnO quasi-shell–core composite and all of the rhodamine B dye was degraded by it only after 10 min of white light illumination. The graphene–ZnO composite with quasi-shell–core structure could effectively improve the separation efficiency of the electrons and holes photoinduced by the ZnO. Ag modification could accelerate the reduction processes of the photogenerated electrons and avoid the accumulation of electrons on graphene, resulting in the promotion of the photocatalytic performance of this composite.