Amorphous titanium dioxide ultra-thin films for self-cleaning surfaces

The overall goal of our research is to develop self-cleaning surfaces on a glass substrate. The self-cleaning surfaces described in this work are based on titanium dioxide coatings. Crystalline titanium dioxide in the anatase form appears to be the most photoactive and the most practical of the semiconductors for widespread environmental photocatalytic applications. However, amorphous TiO2 has been rarely investigated, even though it can be deposited without heating. In this paper, the UV- induced hydrophilicity of amorphous TiO2 thin films obtained by magnetron sputtering deposition were studied in relation to film thickness and nitrogen dopants. The effect of UV light irradiation on the film hydrophilicity was strong and independent of nitrogen dopants or thickness. Surface topography, particle size and film structure were determined by atomic force microscopy and X-ray diffraction.