Photolysis of cerium/thallous solutions. Enhanced reduction rate in the presence of titanium dioxide

Abstract

Aqueous suspensions of titanium dioxide (anatase) in dilute sulfuric acid solution containing ceric and thallous ions have been photolysed. The presence of TiO₂ enhances the reduction rate by at least 40%. The observations are consistent with the formation of an additional yield of oxidizing radicals in the presence of the TiO₂ which react with the same characteristics as the hydroxyl radical. The additional oxidizing radicals generated in the presence of TiO₂ cannot be formed via hydrogen peroxide as an intermediate.