▎ 摘　　要

Graphene-ZnO (G-ZnO) nanocomposites were synthesized by simple and low cost co-precipitation and spin-coating technique. The graphene concentration has been tuned from 3 to 10 at. %. The microstructure and morphology of the synthesized nanocomposite was studied by X-ray diffraction (XRD), Raman spectroscopy and Scanning Electron Microscopy (SEM) techniques. Structural analysis by x-ray diffraction showed that G-ZnO was found to present hexagonal wurtzite-type structure and Raman spectroscopy showed the formation of graphene component. Compared to pure ZnO, photoluminescence (PL) intensity of the nanocomposites had decreased, due to quenching of photoemission, in the presence of graphene. The photo-response of the G-ZnO nanocomposite expands to the visible region up to 800 nm. A significant Photo-Electro-Chemical (PEC) activity enhancement has been observed for the 3 at.% graphene concentrated sample. Sensing characteristics of G-ZnO films was investigated. A strong improvement of the PEC efficiency has been obtained for the optimum G content of 3 at. %. (C) 2018 Elsevier B.V. All rights reserved.