Through an interplay between scanning tunneling microscopy and density functional theory calculations, it was shown that bridging O vacancies were the active nucleation sites for Au clusters on the rutile (110) surface. It was found that a direct correlation exists between a decrease in density of vacancies and the amount of Au deposited. From the density functional theory calculations it was found that the O vacancy was indeed the strongest Au binding site. It was shown, both experimentally and theoretically, that a single O vacancy could bind 3 Au atoms on average. In view of the presented results, a new growth model for the TiO2 (110) system involving vacancy-cluster complex diffusion was presented.

Bonding of Gold Nanoclusters to Oxygen Vacancies on Rutile TiO2(110). E.Wahlström, N.Lopez, R.Schaub, P.Thostrup, A.Rønnau, C.Africh, E.Lægsgaard, J.K.Nørskov, F.Besenbacher: Physical Review Letters, 2003, 90[2], 026101 (4pp)