Solar photocatalytic degradation of methylene blue in carbon-doped TiO_2 nanoparticles suspension

摘要

Carbon-doped TiO_2 nanoparticles were prepared by sol-gel auto-combustion method and characterized by X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), Brunauer-Emmett-Teller method (BET), UV-vis diffuses reflectance spectroscopy (DRS). UV-vis diffuse reflectance spectra showed that carbon-doped TiO_2 exhibited obvious absorption in the visible light range. The visible light photocatalytic activity of carbon-doped TiO_2 was ascribed to the presence of oxygen vacancy state between the valence and the conduction bands because of the formation of Ti~(3+) species in the as-synthesized carbon-doped TiO_2. The sample calcined at 873 K showed the highest photocatalytic activity under solar irradiation. The effects of photocatalyst concentration, initial concentration of methylene blue, and pH value in aqueous solution were also presented.