The effective utilisation of solar radiation requires the development of novel photocatalysts activated by visible-light. Activity tests of toluene decomposition were carried out in the presence of modified titanium dioxide photocatalysts in which some oxygen ions were substituted by sulfur. The elimination of toluene after 1 hour irradiation of the photocatalysts by a pulsed blue LED yielded 44 percent elimination. Pretreatment in which S-doped TiO2 was irradiated by UV for 1 hour prior to the activity test was effective in decomposing acetaldehyde, even under a pulsed green LED irradiation.
