Sn/Ce co-doping of TiO2 nanoparticles: influence of dopants concentration on optical and structural characteristics

Abstract

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 and 5 mol%, based on MB dye decomposition rate.