In-situ hydrothermal fabrication and photocatalytic behavior of ZnO/reduced graphene oxide nanocomposites with varying graphene oxide concentrations

Abstract

In this study, ZnO/reduced graphene oxide (ZnO/rGO) nanocomposites with various GO concentrations were hydrothermally fabricated. We showed that ZnO and rGO phases coexist in these ZnO/rGO nanocomposites and that the ZnO morphology varies from nanoplates to nanoparticles, with the average ZnO nanocrystal decreasing in size from 38 nm to 20 nm as the GO concentration increased from 0% to 10%. Oxygen-containing functional groups were strongly reduced during the ZnO/GO hybridization process used to form these nanocomposites. The visible 400–800 nm absorption band of the rGO layers increased in intensity with increasing GO concentration. Photocatalytic activity of ZnO/rGO nanocomposite samples was studied under visible light for 60 min. The photocatalytic properties of the ZnO/rGO nanocomposites were significantly superior to those of pure ZnO, with photocatalytic efficiency increasing with increasing GO concentration. Photocatalytic efficiency of ZnO/rGO nanocomposites increased by 30%, 32%, and 60% for samples with 4%, 6%, and 10% GO concentration respectively, after 60 min. These results highlight the potential of the ZnO/rGO nanocomposites for use in pollution-remediation applications.