Simultaneous improvement of photocatalytic and superhydrophilicity properties of nano TiO2 thin films

Anatase TiO2 nano thin films were prepared on glass substrates by sol-gel dip coating method using Tween-80 as a surfactant, TiCl4 as the Ti precursor, and ethanol as a solvent. Atomic force microscopy, X-ray diffraction, and UV-Vis. photospectrometery experiments were performed to analyze the surface, structural and optical characteristics of the films. The effects of chemical aging time on the morphology, photocatalytic and superhydrophilicity behaviors of the films were studied. We show there is an optimum aging time at 2 h which photocatalytic and superhydrophilicity properties are at their maximum values simultaneously. This is useful in the self-cleaning industry. (c) 2012 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.