Photoinduced properties of titanium dioxide thin films
Institute of Electronic Materials Technology (ITME), Wólczyńska 133, Warszawa 01-919, Poland
Photocatalytic activity and surface water wettability conversion of TiO2 thin films prepared by DC magnetron sputtering from ceramic target has been studied. Thin films were deposited at three deposition pressures. It resulted in obtaining different film microstructures. Higher deposition pressures favourited creating more porous films with higher specific area than it happened in case of lower pressures. In both cases films were columnar in character with columns consisting of small nanograin-type creatures. Films recognized by X-ray as amorphous ones crystallised to anatase by annealing at 573-773K. It was found that deposition pressure influenced not only the initial film microstructure but the way of anatase crystallization during annealing as well. Strong preferential (001) orientation was found in case of films prepared at higher deposition pressures. To evaluate photocatalytic activity of TiO2 films ethanol breakdown was measured. Water contact angle measurements showed that thin films were hydrophobic if stayed in dark. During UV light irradiation they converted to hydrophilic. Reaction rate and contact angle decrease rate occurred to be dependent in similar way on initial film microstructure, its crystallinity and the way of anatase crystallization.
Presentation: Oral at E-MRS Fall Meeting 2008, Symposium D, by Henryk Tomaszewski
See On-line Journal of E-MRS Fall Meeting 2008
Submitted: 2008-05-05 13:19 Revised: 2009-06-07 00:48