Low-Temperature In Situ Reaction Synthesis of Quasi Core–Shell ZnO/rGO Composites for the Efficient Photocatalytic Degradation of MB

Quasi core–shell ZnO/rGO composites were prepared from Zn2(OH)2CO3 and graphite oxide (GO) as raw materials by solid-phase reaction. The effects of GO content and heating rate on the photocatalytic performance of the products were studied. XRD results showed ZnO/rGO composites were obtained at 300 °C for 2 h, and transmission electron microscopy results showed graphene was coated with ZnO nanoparticles with a particle size of about 20–50 nm and formed a quasi core–shell structure. The photocatalytic experiment results indicated the ZnO/rGO composites exhibited good photocatalytic performance. Under simulated sunlight irradiation, ZnO/30% rGO composite materials demonstrated the best photocatalytic activity for methylene blue, with a degradation rate of 99.6% after 60 min of illumination. Finally, a photocatalysis mechanism of quasi core–shell ZnO/RGO composites was proposed.