ZnO nanorod arrays co-loaded with Au nanoparticles and reduced graphene oxide: Synthesis, characterization and photocatalytic application

•ZnO nanorod arrays co-loaded with Au nanoparticles and RGO were prepared for the first time.•The sample shows enhanced photocatalytic activity due to the synergetic effect of RGO and Au.•The enhanced visible light absorption and transfer rate of electrons contribute to the high activity.

ZnO nanorod arrays (NRAs) co-loaded with Au nanoparticles (NPs) and reduced graphene oxide (RGO) are fabricated using a simple one-step electrochemical deposition method. The obtained photocatalysts were characterized by field emission scanning electron microscopy, X-ray diffractometer, photoluminescence and UV–vis absorption spectra. The photocatalytic activity of the as-prepared samples was investigated by degradation of methylene blue under visible light irradiation. The results showed that Au/RGO–ZnO NRAs exhibited much higher photocatalytic activity than RGO–ZnO NRAs, Au–ZnO NRAs and pure ZnO NRAs. The synergistic effect of Au NPs and RGO enhances visible light absorption range and transmits the hot electrons more efficiently. This research will encourage more rational design of efficient visible light responsive photocatalysts.

Graphical abstractA novel multi-heterojunction photocatalyst (graphene and Au co-loaded ZnO nanorod array) was prepared for the first time. The as-obtained samples showed much higher activity compared to pure ZnO NRAs, Au–ZnO NRAs and RGO–ZnO NRAs for dye degradation, which is almost 9 times higher than that of pure ZnO NRAs.Figure optionsDownload full-size imageDownload as PowerPoint slide