Atmospheric pressure CVD growth of photocatalytic titanium dioxide thin films on tin oxide

We have used thermal Chemical Vapour Deposition (CVD) to grown TiO ₂ films on glass coated with SnO₂ using both titanium tetraisopropoxide (Ti(C₃H₇O)₄,TTIP) and titanium tetrachloride (TiCl₄) and ethyl acetate as precursors. We find that whereas TTIP yields exclusively anatase as expected at the temperatures in question (550°C), the use of TiCl₄ and ethyl acetate at 650°C yields a mixture of anatase and rutile Sample characterisation included X-ray diffraction, Raman, X-ray photoelectron spectroscopy and the stearic acid test for photoactivity. It is found that films deposited on the SnO₂-coated glass using TTIP show a higher photocatalytic activity than that for films deposited on barrier glass, whereas those deposited from TiCl₄ and ethyl acetate, do not. These findings are discussed in terms of possible morphological effects arising from the presence of the SnO₂ underlayer.