In this study, different samples of Sn and Ce co-doped TiO2 nanoparticles (0.5-1-2 mol% Ce and 1-5-10 mol% Sn) were prepared via simple sol−gel synthesis method by using cerium nitrate hexahydrate as cerium precursor, Tin(II) chloride dehydrate as Tin precursor, and titanium (IV) butoxide (TBT) as titanium precursor. The effects of co-doping on the structural, optical, and photo-catalytic properties of nanoparticles were studied by X-ray diffraction (XRD), Field emission SEM (FE-SEM), TEM and UV-Vis absorption spectroscopy. Surface chemical state of nanoparticle was thoroughly examined by atomic X-ray photoelectron spectroscopy (XPS). XRD results showed that, titania rutile phase formation in ternary system (Ti–Ce–Sn) was inhibited by Ce+4 and promoted by Sn+4 co-doped samples at higher percentage of Sn (5%, 10%). The prepared co-doped TiO2 photocatalyst nanoparticles showed optical absorption edge in the visible light region and exhibited excellent photo-catalytic ability for degradation of methylene blue (MB) solution under visible irradiation. Sn/Ce co-doped TiO2 showed higher catalytic activity under visible light irradiation. Visible photo-catalytic activity of Sn/Ce co-doped TiO2 was obviously higher than that of pure TiO2 and reached the maximum at Ce and Sn contents of 2 mol% and 5 mol%, based on MB dye decomposition rate.
