Abstract: The photocatalytic reaction of sulfur dioxide with heptane was carried out with the aid of UV-illuminated titanium dioxide ultrafine particles(UFP) at room temperature. The TiO₂ UFPwas prepared by means of colloidal chemical method. The structure and the surface state of the as prepared TiO₂ UFP via different heat-treatments were studied. As the calcining temperature decreased, the contents of hydroxyl on the surface increased, which could help to enhance the photocatalytic activity of the TiO₂ UFP. The mechanism of the photocatalytic reaction of sulfur dioxide with heptane was proposed, in which there was a competition of photocatalytic oxidation between sulfur dioxide and heptane over the TiO₂ UFP. It is inferred that the reactive oxygen species play an important role in the photocatalytic reaction of sulfur dioxide with heptane.

Key words: Sulfur dioxide, Heptane, Titanium dioxide photocatalysis, Reactive oxygen species