Direct Visualization of a Gold Nanoparticle Electron Trapping Effect.

A new atomic-scale anisotropy in the photoreaction of surface carboxylates on rutile TiO(110) induced by gold clusters is found. STM and DFT+U are used to study this phenomenon by monitoring the photoreaction of a prototype hole-scavenger molecule, benzoic acid, over stoichiometric (s) s-TiO, Au/s-TiO, and reduced (r) Au/r-TiO. STM results show that benzoic acid adsorption displaces a large fraction of Au clusters from the terraces toward their edges.