Dioxygen evolution from inorganic systems. Water oxidation mediated by RuO2 and TiO2-RuO2 Colloids

The kinetics of reduction of aqueous solutions of CeIV and Ru(bpy)33+ in the presence of catalytic amounts of RuO2 colloids stabilized with polybrene and colloidal TiO2 particles loaded with RuO2 have been investigated by means of stopped-flow spectrophotometric techniques. The effect of pH, catalyst preparation and loading concentration have been considered. The TiO2/RuO2 colloidal particles (45 nm radius) are extremely active catalysts.