Au-TiO2 nanofilms for enhanced photocatalytic activity

Abstract

Au/TiO2 nanofilms are prepared on indium-tin oxide glass using magnetron sputtering. The bilayer nanofilms are heat-treated at 500°C in air for 2h. The microstructure evolution of the prepared Au/TiO2 nanofilms is characterized, using scanning electron microscope, energy dispersive spectrometer, and X-ray diffraction. The heat treatment leads to the migration of Au atoms to form Au/TiO2 nanofilms with TiO2 being in anatase phase and the presence of Au films/islands on the surface of the Au/TiO2 nanofilms. The photocatalytic activity of the prepared Au/TiO2 nanofilms in an aqueous solution of methylene blue (MB) is evaluated under the irradiation of visible light. The experimental results show that the photocatalytic activity of the prepared Au/TiO2 nanofilms depends on the loading amount of Au. The rate constant for the photodegradation of the MB compound in the aqueous solutions with pure TiO2 nanofilms is less than those with the prepared Au/TiO2 nanofilms. Such behavior can be likely attributed to the activation of the photo-generated charge carriers and the increase of the electron–hole separation efficiency through localized surface plasmon resonance.