Nucleation and Growth of 1D Water Clusters on Rutile TiO₂(011)-2×1

We present a combined experimental and theoretical study of the adsorption of water on the rutile TiO 2 (011)-2×1 surface, whose “brookite (001)-like” reconstruction has been recently elucidated. By using scanning tunneling microscopy and density functional theory calculations, we provide evidence that water adsorbs weakly on the stoichiometric surface, while hydroxyls resulting from water dissociation at surface O vacancies act as nucleation centers for the growth of H-bonded water clusters that are confined in one dimension.