Synthesis of nanocrystalline Ga-TiO2 powders by mild hydrothermal method and their visible light photoactivity

In this work, nano-sized gallium doped titanium dioxide (Ga-TiO2) powders with different dopant concentrations (0.1, 0.6 and 1.2 mol%) were synthesized by a mild hydrothermal method dwelling at 150 degrees C for 10 h without any post heat treatment. The synthesized samples were characterized by X-ray diffraction (XRD), Brunauer-Emment-Teller (BET) specific surface area, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV-visible light diffuse-reflection spectra (DRS). The photocatalytic activities were evaluated via photocatalytic decolorization of methyl orange under 420-780 nm visible light irradiation. Due to the small particle size, large specific surface area, improved visible light response and enhanced separation of photo-excited carriers, Ga-TiO2 photocatalysts exhibit better photocatalytic activity than that of Degussa P25 or un-doped TiO2, which prepared under the same processing conditions. Among all the Ga doped TiO2 photocatalysts, 0.6 mol% Ga TiO2 shows the best photo-decolorization efficiency reaching up to 82%. (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.