Synthesis of graphene-ZnO nanorod nanocomposites with improved photoactivity and anti-photocorrosion

A series of graphene-ZnO (GR-ZnO) nanorod nanocomposites with different weight addition ratios of graphene (GR) have been prepared via a facile hydrothermal reaction of graphene oxide (GO) and ZnO nanorods. X-ray diffraction (XRD), UV-vis diffuse reflectance spectra (DRS), field-emission scanning electron microscopy (FE-SEM), electrochemical impedance spectroscopy (EIS), photoluminescence (PL) spectra, and electron spin resonance (ESR) spectra are employed to determine the properties of the samples. It is found that GR-ZnO nanorod nanocomposites with a proper addition amount of GR exhibit higher photocatalytic activity and improved anti-photocorrosion than ZnO nanorods toward liquid-phase degradation of dye under ultraviolet (UV) light irradiation. The improved photoactivity and anti-photocorrosion of GR-ZnO nanorods can be ascribed to the integrative synergistic effect of enhanced adsorption capacity, the prolonged lifetime of photogenerated electron-hole pairs and effective interfacial hybridization between GR and ZnO nanorods. This study also shows that graphene sheets act as electronic conductive channels to efficiently separate the photogenerated charge carriers from ZnO nanorods. It is hoped that our current work could promote increasing interest in designing the nanocomposites of one-dimensional (1D) semiconductor and two-dimensional (2D) graphene for different photocatalytic applications.