ATMOSPHERIC PRESSURE CVD GROWTH OF PHOTOCATALYTIC TITANIUM DIOXIDE THIN FILMS ON TIN OXIDE

摘要

We have used thermal Chemical Vapour Deposition (CVD) to grown TTO_2 films on glass coated with SnO_2 using both titanium tetraisopropoxide (Ti(C_3H_7O)_4, TTIP) and titanium tetrachloride (TiCl_4) and ethyl acetate as precursors. We find that whereas TTIP yields exclusively anatase as expected at the temperatures in question (55O℃), the use of TiCl_4 and ethyl acetate at 650℃ 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 SnO_2-coated glass using TTIP show a higher photocatalytic activity than that for films deposited on barrier glass, whereas those deposited from TiCl_4 and ethyl acetate, do not. These findings are discussed in terms of possible morphological effects arising from the presence of the SnO_2 underlayer.