Synthesis of TiO2/Pt/TiO2 multilayer films via radio frequency magnetron sputtering and their enhanced photocatalytic activity

TiO2/Pt/TiO2 (TPT) multilayered films with different thicknesses of Pt layers from about 0.75 to 12 nm were prepared by radio frequency magnetron sputtering method. The as-prepared films were characterized by X-ray diffraction, scanning electron microscopy, atomic force microscopy, UV–visible diffuse reflectance spectroscopy, and photoluminescence spectroscopy. The photocatalytic activity of the samples was evaluated by the photocatalytic decolorization of methyl blue aqueous solution under ultraviolet light irradiation. The photocatalytic activities of all TPT multilayer films were higher than that of the pure TiO2 films. When Pt thickness was increased to 3 nm, the measured photocatalytic activity of the TPT film was highest, and exceeded that of the pure TiO2 films by a factor of more than three times. Such enhancement was ascribed to the presence of Pt layer, which inhibits the recombination of the photogenerated charge and carriers, as well as modifies the crystallinity of the TiO2 top layer.

► The TiO2/Pt/TiO2 multilayer films were prepared by magnetron sputtering.
► The TiO2/Pt/TiO2 multilayer films have different thicknesses of Pt layers.
► The photocatalytic properties of all films were studied upon UV irradiation.
► The TiO2/Pt/TiO2 multilayer films show enhanced photocatalytic activities.