[Study of photocatalytic activity, characterization and preparation of supersuspended nano-TiO2. II. Study of photocatalytic activity].

From the change in the absorption of methyl-orange solution at 470 nm, the photocatalytic activity of nano-TiO2 prepared by pyrolysis method, and then by cooling treatment in silicon oil and in air respectively, was studied with methyl-orange solution as model waste water under irradiation by UV-lamp. Their photocatalytic mechanisms, the percentage of degradation in 35 min and the kinetic reactive process were also analyzed. The results show that the photocatalytic activity of both products is obvious with little difference. However, the nano-TiO2 powder modified with silicone oil can degrade harmful components more effectively on the surface of waste water with sunlight and other extra light.