Effect of gold nanoparticles on the photocatalytic efficiency of ZnO films

This study presents a simple and inexpensive method for preparation of ZnO/Au thin film photocatalysts. Nanostructured ZnO and modified with gold nanoparticles zinc oxide films are obtained on glass substrate by dip-coating technique. The precursor suspension is prepared using commercial ZnO powder, ethanol and polyethyleneglycol, while the gold nanoparticles are obtained by classical citrate synthesis. Thin ZnO and ZnO/Au films are characterized by Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), X-ray diffraction and UV-Vis spectroscopy. The photocatalytic action of the samples is studied in respect to Malachite Green photodegradation under UV and visible light irradiation. The modified ZnO/Au films manifest higher photocatalytic efficiency under UV and visible light illumination in comparison to ZnO ones. A possible mechanism for explanation of the observed effect is proposed.