Effects of the Physicochemical Properties of Rutile Titania Powder on Photocatalytic Water Oxidation

Water oxidation to form molecular O-2 over illuminated rutile TiO2 powder in the presence of a reversible electron acceptor (IO3- or Fe3+) was studied with respect to the effects of the physicochemical properties of rutile TiO2. Commercially available nanoparticulate rutile was calcined in air at 873-1273 K for 2 h to prepare crystallized rutile with varying particle sizes. Calcination at 1073 K resulted in the highest activity, regardless of the electron acceptor employed. High-temperature calcination facilitated crystallization of the rutile particles, enhancing the activity, while also reducing the oxygen vacancy density, thus lowering the material's charge transport capability.