Hierarchical ZnO Nanosheet-Reduced Graphene Oxide Composites for Photocatalytic Ethylene Oxidation

Hierarchical ZnO nanosheet-reduced graphene oxide (RGO) nanocomposites were prepared via a simple one-step process under ambient conditions. The resultant ZnO–RGO nanocomposites are composed of highly branched ZnO nanosheets with RGO sheet decoration. It is found that GO precursors could modulate the branched structure of ZnO nanosheets effectively. The shape of hierarchical ZnO nanosheets is effectively tuned by controlling the weight ratio of GO during the synthesis. The ZnO–RGO composites exhibit good photocatalytic performance for ethylene oxidation under simulated sunlight illumination. The photocatalytic oxidation performance of ZnO–RGO photocatalysts could be further enhanced by optimizing the mass ratio of GO to 2%, which showed excellent stability as well. The mineralization rate of ethylene is ∼100% in this reaction. The detailed characterization revealed that the enhanced photo-oxidation performance was attributed to the intimate contact between RGO nanosheets and ZnO nanoparticles, which played important roles in increasing light absorption intensity and promoting the separation and migration of the photoinduced charge carriers.