Effects of S and Ta codoping on photocatalytic activity of rutile TiO2

Abstract

In this study, pure titanium dioxide (TiO2), Ta-doped TiO2, S-doped TiO2, and Ta-S-codoped rutile TiO2 photocatalysts were prepared by a sol-gel method. To evaluate the properties of the synthesized samples, X-ray diffraction analysis (XRD) and X-ray photoelectron spectroscopy (XPS) were applied. XRD detection results showed that the samples contained rutile phase basically. Scanning electron microscope observation showed that the morphology of Ta-S-TiO2 was nearly spherical. Transmission electron microscope investigation indicated that Ta-S-TiO2 had a flower-shaped structure consisting of many nanorods. The measurement of Brunauer-Emmett-Teller (BET)-specific surface areas (SBET) showed that tantalum and sulfur codoping can effectively increase the SBET of TiO2. XPS results indicated that Ta was in the form of Ta5+ in the TiO2 structure. Finally, the photocatalytic activities of synthesized photocatalyst samples were measured for the degradation of methylene blue in ultraviolet and visible light irradiation. The results demonstrated that the Ta-S-codoped rutile TiO2 photocatalyst had better photocatalytic performance than pure rutile TiO2, Ta-doped rutile TiO2 and S-doped rutile TiO2 photocatalyst.