Two-component transparent TiO2/SiO2 and TiO2/PDMS films as efficient photocatalysts for environmental cleaning

TiO2 films modified either with polydimethylsiloxane (PDMS) or SiO2 were prepared by a sol–gel method combined with dip-coating. TiO2/PDMS films have a lower abrasion resistance and are more hydrophobic than the TiO2/SiO2 ones. As the TiO2/PDMS films calcined at 350–450 °C exhibit developed micro-mesoporosity, they adsorb considerable amounts of methylene blue from its water solution. However, their photocatalytic activity in the decomposition of this dye is very low. On the contrary, these films are highly active in the degradation of the layers of methyl stearate. This efficiency variation is explained by the film-developed porosity. The films modified with SiO2 have very good abrasion resistance and can be easily converted by weak UV-illumination into substantially stable superhydrophilic state. Furthermore, they exhibit good photocatalytic properties in both test reactions.