Green Synthesis of ZnO-GO Composites for the Photocatalytic Degradation of Methylene Blue

Abstract

Beneficial from the excellent optical performance of zinc oxide (ZnO) nanocrystals and the absorption properties of graphene oxide (GO), the nanocomposites of ZnO and GO with synergistic photocatalytic effects were prepared by a precipitation method, in which GO is utilized as the catalyst carrier. The prepared composites were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, UV-vis spectroscopy, field emission scanning electron microscopy, and transmission electron microscopy and also performed photocatalytic activity for the nanocomposites. The results show that ZnO is uniformly loaded on the surface of GO assisted by an effective interface coupling. Due to interface coupling between ZnO and GO, electrons can be directly transferred from the valence band of ZnO to GO. The photodegradation efficiency of the composites reaches to 97.6%, and the first-order reaction rate constant of photodegradation is calculated to be 0.04401 min-1. The novel ZnO-GO composites with excellent photocatalytic performance display promising potential applications in the field of photocatalysis and will provide a new platform for building next-generation graphene-based semiconductor composites.