Abstract: The nano-crystal composite WO3-TiO2 photocatalyst was prepared by ultrasonic assisted sol-gel process. The e®ects of various factors, such as the crystal form, the substrates, the pH, the dissolved oxygen and the ultrasonic on the photocatalytic activity were investigated in view of the photodegradation of Rhodamine B. The results show that the crystal form of WO3-TiO2 film with highest photocatalytic activity is rutile. The introduction of ultrasonic to the course of preparation can accelerate the deposit time of the sol and increase the photocatalytic activity signi¯cantly in view of the highest photodegradation of Rhodamine B being 72.7% in 5 hours. The porous titanium plate is the most suitable substrate in four kinds of investigated materials. Meanwhile the smaller the pH and the higher the concentration of the dissolved oxygen in the solution is, the higher the photodegradation is.

Key words: ultrasonic, sol-gel process, photocatalytic, photodegradation