Effects of surfactants on microstructure and photocatalytic activity of TiO2 nanoparticles prepared by the hydrothermal method

TiO2 nanoparticles were prepared using a surfactant (linoletic acid (LA) or polyethylene glycol-400 (PEG-400)) at various hydrolysis ratios (R=H2O/C2H5OH) by the hydrothermal method and studied for photocatalytic degradation of rhodamine B (RhB) under visible light irradiation. Special shapes of TiO2 nanoparticles, such as cubic, hexagon, bipyramid, and bullet, were found from the use of PEG-400 during the preparation. The cause for the formation of these special shapes is also discussed here. Interestingly, the hydrolysis ratios affected the Brunauer-Emmett-Teller (BET) special surface areas of the TiO2 nanoparticles. Owing to the effects of the surfactant PEG-400 on the microstructures, the resulting materials exhibited relatively higher photocatalytic activity than conventional TiO2 nanoparticles in the presence of LA. Furthermore, P-TiO2-8/10 (P is PEG-400 and 8/10 is H2O/C2H5OH molar ratio) nanoparticles had a similar photocatalytic activity to P25 and TiO2-10/10. 2011 (c) Elsevier Ltd. All rights reserved.