Photocatalytic decomposition of oil in water

Various titanates prepared by calcination of a mixture of KOH [Ba(OH)(2) or Ca(OH)(2)] and titanium dioxide slurry with a slightly crystallized structure were used as photocatalyst in the reaction of oil decomposition in water. The influence of both the calcination temperature and the kind of metal used on the photocatalytic activity of resulted titanates in the oil decomposition reaction in water have been studied. The phase composition of photocatalysts was determined by XRD technique. The correlation between the photocatalyst content, time of UV-illumination and the rate of oil decomposition were presented. The most active material was prepared fi om a slightly crystallized titania precursor and potassium hydroxide calcinated at 550 degrees C. The complete oil decomposition was achieved after 2 h of UV illumination with the photocatalyst content of 0.5 g dm(-3). The photocatalyst forms a complex mixture of various titanium oxides and titanates that are probably responsible for the increase of activity. For the most active TiO2/KOH photocatalyst the optimal preparation conditions were established. (C) 2000 Elsevier Science Ltd. All rights reserved.