Transparent anatase TiO2 nanometer thin films with photocatalytic activity
were prepared via the sol-gel method on soda-lime glass, fused quartz, and
soda-lime glass precoated with a SiO2 layer. The resulting thin films were
characterized by X-ray photoelectron spectroscopy (XPS), scanning electron
microscopy (SEM), and X-ray diffraction (XRD). The photocatalytic activity
of the various TiO2 films was evaluated by the photocatalytic decolorizatio
n of aqueous methyl orange. The diffusion of sodium and calcium ions from t
he soda-lime glass into the nascent TiO2 films was found to be detrimental
to the photocatalytic activity of the resulting TiO2 films. Sodium and calc
ium diffusion into nascent TiO2 films was effectively retarded by a 0.3 mum
SiO2 interfacial layer formed on the soda-lime glass. (C) 2000 Elsevier Sc
ience Ltd. All rights reserved.