Controllable synthesis and photocatalytic activities of water-soluble TiO2 nanoparticles

Water-soluble anatase, mixed-phase (anatase and rutile) and rutile TiO2 nanoparticles (NPs) or nanorods were synthesized under mild solution conditions using polyethylene glycol 400 (PEG 400) as a stabilizer and HCl as a phase controlling reagent. The photocatalytic properties of these NPs with different crystal phases were evaluated by photocatalytic degradation experiments of methyl orange (MO). As-prepared pure anatase TiO2 NPs show a higher photocatalytic activity than other samples and commercial P25, which may be related to the high crystallinity, the pure anatase phase, small size and the enhanced absorbability associated with the existence of PEG 400 on the NP surface. (C) 2010 Elsevier B.V. All rights reserved.