Natural superhydrophilicity and photocatalytic properties of sol-gel derived ZnTiO3-ilmenite/r-TiO2 films

The additive free heteronucleation and nanocrystallization of ternary Zn x Ti y O z sols and coatings is presented. A proper adjustment of the Zn/Ti ratio in the sol allows the formation of elaborate superhydrophilic cubic spinel-like Zn 2 TiO 4 , c-ZnTiO 3 or h-ZnTiO 3 -ilmentite/r-TiO 2 -rutile films. Their morphology and natural superhydrophilicity can be fine-tuned by the inclusion of 5% silica. This doping step delivers high dye intake capacities and water contact angle values below 3°. XPS analysis indicates that Zn and Si enrichment enables greater surface hydroxylation and thus improved water wetting behaviour. The transparent h-ZnTiO 3 -ilmenite/r-TiO 2 nanocomposite coatings deposited on glass and Si-wafers show a remarkable activity in the photomineralization of fatty-acids. Efficient fatty-acid photodegradation on superhydrophilic sol-gel derived ZnTiO 3 -ilmenite/r-TiO 2 coatings.