Photocatalytic TiO2 Coatings: Effect of Substrate and Template

Transparent TiO2 films with a high photodegradation activity towards an azo dye in aqueous solution were prepared by sol-gel processing. Films on soda-lime glass supports protected with a thin silica barrier layer exhibited better crystallization and monodisperse nanoparticles, higher absorption of light below 370nm, and higher photocatalytic activity than those films deposited on bare glass supports proving the detrimental effect of interdiffused sodium ions on the development of the anatase nanostructure. The effect of substrate was more pronounced in thinner films (300nm) than in thicker ones (1200nm), which were achieved by adding a template (i.e. Pluronic F127) to the sol.