Solar photocatalytic degradation of methylene blue using doped TiO^sub 2^ nanoparticles

Doped-TiO2 nanoparticles (M:TiO2: Fe, Zn, Zr, Sb, Ce and nM:TiO2: B, C, N, P, S) with anatase structure were prepared by sol-gel method and characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS), Brunauer-Teller method (BET), UV-Vis diffuses reflectance spectroscopy (DRS). Results revealed that the anatase structure is highly stable for all doped TiO2 prepared compounds with enhancement in the surface area. UV-Vis diffuse reflectance spectra showed that these dopants were responsible for narrowing the band gap of TiO2 and shifting its optical response from ultraviolet to visible-light region. The photocatalytic activities of these multi-doped TiO2 catalysts were investigated by degradation methylene blue in aqueous solution under solar-light illumination. The results showed an appreciable enhancement in the photoactivity of the C-doped TiO2 as compared to other multi-doped TiO2 because of the formation of Ti+3 species which prevent the recombination of electron-hole pairs in C-doped TiO2. [PUBLICATION ABSTRACT]