| AVS 56th International Symposium & Exhibition | |
| Surface Science | Monday Sessions |
| Session SS2-MoM |
| Session: | TiO2 Surfaces and Interfaces |
| Presenter: | S.E. Chamberlin, University of Wisconsin - Milwaukee |
| Authors: | S.E. Chamberlin, University of Wisconsin - Milwaukee H.C. Poon, University of Wisconsin - Milwaukee D.K. Saldin, University of Wisconsin - Milwaukee C.J. Hirschmugl, University of Wisconsin - Milwaukee |
| Correspondent: | Click to Email |
The surface of TiO2 has been extensively studied to explore its potential for many applications, including the harvesting of solar light and the photocatalysis of water [1-3]. The majority of studies have focused on the thermodynamically most stable rutile (110) face [4], however, other faces are almost as important. For example, the rutile (011) face may have enhanced activity towards water dissociation [5], but is less studied. Crucial to understanding the mechanisms by which these processes occur is determining the atomic structure and chemistry of the surface.
The (011) surface of TiO2 is known to exhibit a (2x1) reconstruction [6] and several models of the surface have been proposed [6-9]. The present work extends quantitative low energy electron diffraction (LEED) to reconstructed oxide surfaces in order to determine which, if any, of these models are supported by LEED-IV. I-V curves, with a total energy range of ~2200 eV, were extracted for 20 beams using a novel, low-current, delay-line-detector LEED (DLD-LEED) system to minimize effects due to charging and electron beam damage. Structural refinement from the LEED-IV analysis confirms the Brookite model [8] found by surface x-ray diffraction, with agreements in atomic displacements to within 0.04 Å perpendicular to the surface and 0.12 Å parallel to the surface. The resulting Pendry R-factor is 0.29 which definitively excludes the other proposed models that give significantly higher R factors.
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