Removal of metals using a ZnO/Au composite under visible-light illumination

Abstract

Gold nanoparticles embedded into a ZnO film are prepared with a simple spin-coating technique. Photocatalytic performance of the film is studied under irradiation with the visible light. We suggest to increase the amount of Au nanoparticles in the ZnO matrix (from 0 to 400 mg in our particular case) to improve photocatalytic efficiency of the film via a combination of plasmonic-resonance and Schottky-barrier effects. We choose Fe2+ as a model representative of metals available in the wastewater. It is demonstrated that the ZnO/Au films with increased Au content reduce efficiently the amount of ferrum ions in the water solution. In particular, the film with the content ratio ZnO:Au = 1:2 serves as a good absorber for removing Fe2+ in case if their initial concentration is equal to 0.2 mM.