Hierarchical ZnO/S,N:GQD composites: Biotemplated synthesis and enhanced visible-light-driven photocatalytic activity

Graphene quantum dots co-doped with sulfur and nitrogen (S,N:GQDs) are successfully combined with leaf-templated ZnO nanoparticles (L-ZnO) to obtain hierarchical L-ZnO/S,N:GQD composites exhibiting highly surface area. The morphology, structure, and the visible-light-driven photocatalytic activity are investigated. Compared with non-templated ZnO/S,N:GQDs, L-ZnO/S,N:GQD composites exhibit higher photocatalytic activity for the degradation of rhodamine B under visible light irradiation. Such elevated photocatalytic activity results from two main effects: one is the highly effective charge separation in L-ZnO/S,N:GQD composites; the other is the high surface area, allowing for efficient capture of the visible light.