One-pot hydrothermal synthesis of ZnO-reduced graphene oxide composites using Zn powders for enhanced photocatalysis

Abstract

Zn powder was successfully utilized as a reducing agent and a precursor of ZnO for one-pot synthesis of reduced graphene oxide (rGO)–ZnO photocatalysts. Two rGO–ZnO composites were synthesized with or without a surfactant, cetyltrimethyl ammonium bromide (CTAB). The structural, morphological, and photochemical properties of the samples were thoroughly investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), N2 adsorption/desorption, UV–vis diffuse reflectance (UV–vis DRS), thermogravimetric-differential thermal analysis (TG-DTA), and Raman spectroscopy. Zn powder could effectively reduce GO to graphene and be transformed to ZnO with the assistance of the surfactant. The surfactant was found to influence the properties of rGO–ZnO. rGO–ZnO photocatalysts could decompose methylene blue under UV–vis illumination and exhibited higher activities than pristine ZnO. The co-existence of GO–rGO would be more favorable to photocatalysis.