Properties of anatase films for photocatalyst from peroxotitanic acid solution and peroxo-modified anatase sol

Anatase films for a photocatalyst have been prepared on substrates by a dip-coating technique using peroxotitanic acid (PTA) solution and peroxo-modified anatase (PA) sol. The as-dried film prepared from PA sol had already crystallized to anatase phase, while the film prepared from PTA solution crystallized above 300 degrees C. Adhesion strength of the films at 300 degrees C was over 60 MPa, and their relative density was over 80%. Photocatalytic efficiency of the film prepared from PA sol for the degradation of acetic acid was higher than that of the film prepared from PTA solution. The films obtained above 300 degrees C from PA sol exhibited the highest catalytic activity. However, the film less than 0.70 mu m thick resulted in decrease of photocatalysis.