Preparation of graphene-ZnO composite with enhanced photocatalytic performance

A composite photocatalyst of zinc oxide (ZnO) nanoparticles decorated with different content of reduced graphene oxide (rGO) was prepared via a simple and facile one-step method in this paper. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectra, and UV-Vis diffuse reflection spectroscopy (UV-Vis DRS) were used to characterize the crystal structure, morphology and optical properties of the rGO-ZnO composite photocatalyst. The photocatalytic properties of the composites were investigated using methyl orange (MO), a typical orange compound, as a test pollutant. The results showed that rGO-ZnO composites displayed significantly enhanced photocatalytic activity in MO degradation than pure ZnO, and the pseudo-first-order kinetic constant on the optimal rGO-ZnO composite was 14 times as great as that on pure ZnO. The enhanced photocatalytic ability of the rGO-ZnO composites was mainly benefited from the high specific surface area and high conductivity of rGO, which facilitated efficient charge separation in the rGO-ZnO nanocomposite.