AVS 51st International Symposium
    Surface Science Wednesday Sessions
       Session SS1-WeA

Paper SS1-WeA6
Water Adsorption on the Rutile TiO2(011)-(2x1) Surface

Wednesday, November 17, 2004, 3:40 pm, Room 210B

Session: Metal Oxides and Clusters II: TiO@sub 2@ and Photocatalysis
Presenter: A. Klust, Tulane University
Authors: A. Klust, Tulane University
T.J. Beck, Tulane University
U. Diebold, Tulane University
C. DiValentin, Universita' degli Studi di Milano-Bicocca, Italy
A. Selloni, Princeton University
Correspondent: Click to Email
Titanium oxide is a promising material for photocatalysis. Previous studies have shown that the photocatalytic activity of rutile TiO@sub 2@ depends dramatically on the surface orientation with the (011) surface being the most active.@footnote 1@ The TiO@sub 2@(011) surface forms a stable (2x1) reconstruction. Based on theoretical modelling and scanning tunneling microscopy (STM) studies, we propose a structural model for this surface. The surface is terminated by one-fold coordinated O atoms (titanyl groups), a feature that distinguishes it from all other known TiO@sub 2@ surfaces. We suggest that the titanyl groups are responsible for the high photocatalytic activity of the TiO@sub 2@(011) surface. Here, we present STM and ultraviolet photoemission (UPS) studies of water adsorption on the TiO@sub 2@(011) surface showing that water adsorb in both molecular and dissociative form at 110 K. First-principles calculations are in agreement with these results and provide detailed information on the structure of the adsorbed molecules. In contrast to the well - known (110) surface@footnote 2@, water dissociation is not mediated by surface defects demonstrating the high chemical activity of the TiO@sub 2@(011)-(2x1) surface. @FootnoteText@ @footnote 1@ G.S. Rohrer in: The Chemical Physics of Surfaces (2001), ed. D.P. Woodruff.@footnote 2@ I.M. Brookes et al. Phys. Rev. Lett. 87 (2001) 266103; R. Schaub et al. Phys. Rev. Lett. 87 (2001) 266104.