Effects of calcination temperatures on photocatalytic activity of SnO 2/TiO 2 composite films prepared by an EPD method

Abstract

SnO 2/TiO 2 composite films were fabricated on transparent electro-conductive glass substrates (F-doped SnO 2-coated glass:FTO glass) via an electrophoretic deposition (EPD) method using Degussa P25 as raw materials, and were further characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscope (FESEM), UV–vis diffuse reflectance spectra and Photoluminescence spectra (PL). XRD and XPS results confirmed that the films were composed of TiO 2 and SnO 2. FESEM images indicated that the as-prepared TiO 2 films had roughness surfaces, which consisted of nano-sized particles. The effects of calcination temperatures on the surface morphology, microstructures and photocatalytic activity of SnO 2/TiO 2 composite films were further investigated. All the prepared SnO 2/TiO 2 composite films exhibited high photocatalytic activities for photocatalytic decolorization of Rhodamine-B aqueous solution. At 400 °C, the SnO 2/TiO 2 composite films showed the highest photocatalytic activity due to synergetic effects of low sodium content, good crystallization, appropriate phase composition and slower recombination rate of photogenerated charge carriers.