Sn4+-doped TiO2 nanorod array film with enhanced visible light photocatalytic activity

Abstract

Sn4+-doped TiO2 nanorod array film (NAF) on the fluorine-doped tin oxide (FTO) conducting glass was successfully synthesized using the facile hydrothermal method. The NAF photocatalysts were characterized by the scanning electron microscopy (SEM), X-ray diffraction (XRD) and UV-Vis diffuse reflectance spectra (DRS). The SEM images showed that both doped and pure TiO2 NAFs exhibited a good nanorod array structure. Sn4+-doped TiO2 NAF still maintains rutile crystal structure, which was identical to that of pure TiO2 sample. By means of the DRS measurement, it was found that the Sn4+ doping inTiO2 nanorod could induce an obvious enhancement of visible light absorption owing to the introduction of doping energy level in the band gap of TiO2. The degradation of methyl orange (MO) demonstrated that the Sn4+-doped TiO2 NAF exhibited an enhanced photocatalytic activity than pure TiO2 NAF under the visible light (λ > 400 nm) irradiation, which should be attributed to the enhanced visible light response and improved separation efficiency of photogenerated carriers of Sn4+-doped TiO2.