Enhanced Optical and Photocatalytic Properties of Au/Ag Nanoparticle-decorated ZnO Films

Plasmonic Au- and Ag-decorated ZnO films on a glass substrate were obtained by a plasma electrolyte oxidation method with high-voltage discharge, followed by the decoration of Au nanoparticles (NPs) on their surface. With the increasing concentration of the Ag precursor, the thickness of the Ag-ZnO films decreased and the width of the bandgap increased, causing an enhancement in the near band-edge ultraviolet (UV) emission. With the decoration of the Au NPs, the photoluminescence of the Ag-ZnO films exhibited quenching of the band-edge UV emission, accompanied by the suppression of the visible emission in the photoluminescence spectra, and a significant enhancement in the photocatalytic efficiency for the photodegradation of Rhodamine B under solar simulator irradiation.