Influence of deposition atmosphere on photocatalytic activity of TiO2/SiOx double-layers prepared by RF magnetron sputtering

Abstract TiO 2 /SiO x double-layers have been prepared at room temperature by RF magnetron sputtering. The TiO 2 top-layer was deposited in an Ar atmosphere, while the SiO x bottom-layer was deposited in an Ar/O 2 atmosphere. Samples were characterized using X-ray photoelectron spectroscopy, scanning electron microscopy, atomic force microscopy, and photoluminescence techniques. The photocatalytic activity of the samples was evaluated by the photodegradation of methylene blue; the results showed that the photocatalytic activity of the TiO 2 /SiO x double-layers was superior to that of the TiO 2 single-layers. The presence of the SiO x bottom-layer improved the photocatalytic activity of the TiO 2 layer because it may act as a trap for electrons generated in the TiO 2 layer thus preventing electron-hole recombinations.