Synthesis of a flower-like CuS/ZnS nanocomposite decorated on reduced graphene oxide and its photocatalytic performance

A series of graphene-based materials composed of flower-like CuS/ZnS (CZS) microspheres and reduced graphene oxide (rGO) with different weight ratios have been fabricated via a two-step approach, in which CZS was synthesized first by a hydrothermal method, and then combined with rGO via a sonochemical process to form CuS/ZnS/rGO (CZS/rGO) composites. The photocatalytic activity was studied by photodegradation of methylene blue (MB) in the presence of hydrogen peroxide (H2O2). The results showed that all the graphene-based photocatalysts exhibited enhanced catalytic activity, compared to pure CuS/ZnS (CZS) composites. When the weight ratio of graphene in the composite materials was 20 wt%, the composite presented the highest photocatalytic efficiency, which could eliminate more than 99% of MB within 20 min and the photocatalytic efficiency could be kept at about 99% of the original photocatalytic efficiency after three cycles.