Understanding photocatalytic metallization of preadsorbed ionic gold on titania, ceria, and zirconia.

A nonaqueous photodeposition procedure for forming Au nanoparticles on semiconducting supports (TiO(2), CeO(2), and ZrO(2)) was investigated. Intrinsic excitation of the support was sufficient to induce Au(0) nucleation, without the need for an organic hole-scavenging species. Photoreduction rates were higher over TiO(2) and ZrO(2) than over CeO(2), likely due to a lower rate of photogenerated electron recombination.

Low energy photosynthesis of gold-titania catalysts.

By identifying the Electron Partitioning Effect (EPE) as responsible for the large gold deposits usually formed in the conventional photodeposition method, a low energy UV light-based method for the preparation of comparatively high-activity gold-titania catalysts was developed. These materials were tested in the carbon monoxide (CO) oxidation reaction and returned markedly higher levels of activity at room temperature, when compared to catalysts prepared by the traditional photodeposition method. This is the first instance of using a light-mediated process for preparing catalysts active for the CO oxidation reaction.