Li-doped nanosized TiO2 powder with enhanced photocalatylic acivity under sunlight irradiation

This work reports on the synthesis of Li-doped TiO2 nanoparticles using the sol-gel process and solid-state sintering, and investigates their potential use as a photocatalyst for degradation under sunlight excitation of different organic model compounds in aqueous solution. The structure of the nanocrystals was examined by X-ray diffraction, UV-vis ground state diffuse reflectance absorption spectra and X-ray photoelectron emission spectroscopy. Results showed that samples prepared by sol-gel process and calcined at 400 degrees C are composed of a mixture of anatase and rutile phases, in contrast to the one prepared by solid-state sintering, which exhibits an anatase phase with Li being involved in a spinel phase. The photocatalytic degradation of aqueous solutions of different aromatic compounds was successfully achieved under sunlight excitation in presence of Li-doped TiO2 prepared via sol-gel process. It was shown that the calcination temperature and the preparation mode greatly affect the photocatalytic efficiency. Copyright (C) 2010 John Wiley & Sons, Ltd.