Defected graphene as effective co-catalyst of CdS for enhanced photocatalytic activities.

Synthesis of highly efficient photocatalysts for energy and environment catalysis is still a big challenge in the materials field. Cadmium sulfide (CdS) is a promising visible light-driven photocatalyst, which can be composited with co-catalysts to increase its photo-activity and stability. In this study, a kind of graphene material with abundant structure defects (D-rGO) is synthesized by a two-step annealing process with nitrogen-doped rGO (N-rGO) as an intermediate. The high-temperature annealing could remove the doped heteroatoms to form structure defects with five or seven carbon atoms. The D-rGO is then used as co-catalyst for the modification of CdS nanoparticles, and enhanced photocatalytic activities could be obtained. A large hydrogen evolution rate of 102.7 μmol h-1 g-1 is achieved, which is also effective for 4-nitrophenol reduction with a rate constant of 0.168 min-1. The novel CdS/D-rGO composite contains no noble metals and could be used as multi-functional photocatalysts, thus should has great potential in the photocatalysis field.