Synthesis of Heterostructure Au/ZnO Nanocomposites by Microwave-Assisted Deposition Method and Their Photocatalytic Activity in Methylene Blue Degradation

The heterostructure Au/ZnO composites with different Au content were successfully synthesized by sol-gel method and reduced Au(3+)ions to metallic Au(0)nanoparticles by microwave-assisted deposition method using ethylene glycol as reducing reagent. The crystal structure, morphology and chemical composition of prepared samples were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray (EDS) spectrometer and X-ray photoelectron spectroscopy (XPS). It found the good dispersed metallic face center cubic phase of Au nanoparticles were supported on hexagonal phase of ZnO microparticles. Photocatalytic activity of the heterostructure Au/ZnO nanocomposites were evaluated in the degradation of methylene blue (MB) solution under UV light irradiation. The 5% Au/ZnO composite showed the higher photocatalytic activity than pure ZnO and other Au/ZnO samples (2.5 and 10% Au/ZnO).