Photocatalytic degradation of methylene blue with metal-doped mesoporous titania under irradiation of white light

Metal-doped mesoporous titania was obtained by aging a mixed solution of metal salt, polyacrylic acid (PAA) as a template and titania sol, which had been prepared by disolving titanium tetraisopropoxide (TTIP) in hydrochloric acid solution, at 333 K for 24 hours. All the metal-doped mesoporous titania were prepared from the gel solution and the crystal structure was anatase. The diffuse reflectance spectra of the metal-doped titania powder show to absorb the visible light. The metal-doped mesoporous titania powder was dispersed in an aqueous methylene blue (MB) solution and the adsorption and photodegradation of MB were characterized. The MB concentration was decreased to one-twentieth the initial concentration (48 mum) after about 15 minutes with W-doped mesoporous titania under irradiation of white light. The rapid decrease at the initial stage was caused by the adsorption, and after about 30 min products of the photocatalytic degradation of MB were observed. However, for the Fe- and Cu-doped mesoporous titania adsorbed MB in the initial stage, but the photocatalytic degradation of MB almost did not proceed.