Enhanced sunlight-driven photocatalytic property of Mg-doped ZnO nanocomposites with three-dimensional graphene oxide/MoS2 nanosheet composites

Abstract

Graphene oxide (GO) has been the focus of attention as it can enhance the photocatalytic activity of semiconductors due to its large specific surface area and remarkable optical and electronic properties. However, the enhancing effect is not ideal because of its easy self-agglomeration and low electronic conductivity. To improve the enhancing effect of GO for ZnO, three-dimensional GO/MoS₂ composite carriers (3D GOM) were prepared by electrostatic interactions and then, Mg-doped ZnO nanoparticles (MZ) were supported on the surface of 3D GOM by utilizing the layer-by-layer assembly method. Compared with GO/Mg-ZnO composite (GOMZ), the resultant three-dimensional GO/MoS₂/Mg-ZnO composite (GOMMZ) exhibited excellent photocatalytic performance due to the effective synergistic effect between GO and MoS₂ sheet, and its degradation rate was nearly 100% within 120 min of exposure to visible light; this degradation rate was nearly 8 times higher than that of the GOMZ composite. Moreover, the introduction of the MoS₂ sheet intensified the photocurrent density of the GOMZ composite and endowed it with optical memory ability.