One-step hydrothermal preparation and photocatalytic activity of (C, S, Sm)-tridoped mesoporous TiO2 photocatalyst under visible light irradiation

(C, S, Sm)-tridoped mesoporous TiO2 is prepared by one-step hydrothermal method and characterized by X-ray diffraction (XRD), scanning electronic microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) method, UV–vis diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) spectroscopy. By analyzing the structures and photocatalytic activities of (C, S, Sm)-tridoped TiO2 under visible light irradiation, the probable mechanism of tridoped TiO2 is investigated. It is assumed that the co-operation of nonmetal elements (C, S) and samarium not only leads to appreciable narrowing of the band gap, but also promotes the separation of the photo-generated electrons and holes, thus greatly improving the photocatalytic activity under visible light irradiation. The photocatalyst doped with C, S, and 1.0% Sm3+ shows the highest photocatalytic activity.