| AVS 60th International Symposium and Exhibition | |
| Surface Science | Tuesday Sessions |
| Session SS+AS-TuM |
| Session: | Synthesis, Structure and Characterization of Oxides |
| Presenter: | S. Wendt, Aarhus University, Denmark |
| Correspondent: | Click to Email |
In this talk, I will summarize surface science studies conducted at the iNANO center addressing a prototypical model oxide system – the rutile TiO2(110)–(1 × 1) surface. The identification of point defects on the terraces such as oxygen vacancies, hydroxyl groups, and near surface defect such as Ti interstitials will be discussed. Using high-resolution scanning tunnelling microscopy (STM) several examples for reaction of molecules with oxygen vacancies will be presented [1]. These reactions were directly imaged in so-called STM movies. Whereas the reactions on the terraces can be imaged directly, a combination of static STM results with temperature-programmed desorption (TPD) measurements was used to study the reactions at step edges, with the focus particularly on the <1-11> step edges [2,3]. Both, for the reaction on the terraces and at the step edges, water and ethanol were used as probe molecules [1-3]. Accompanying density functional theory (DFT) calculations support the assignments made in the STM studies. In addition, I will address the complex oxygen–TiO2(110) interaction [4]. Specifically, the role of bulk defects in the oxygen chemistry on reduced rutile TiO2(110) is highlighted. Finally, I will show that these surface science studies help to improve our understanding of TiO2 as photo-catalysts. Specifically, the photo-reaction of ethanol on differently prepared TiO2(110) surfaces will be compared.
[1]J. Ø. Hansen, P. Huo, U. Martinez, E. Lira, Y.Y. Wei, R. Streber, E. Lægsgaard, B. Hammer, S. Wendt, F. Besenbacher, Phys. Rev. Lett. 107, 136102 (2011).
[2] U. Martinez, J. Ø. Hansen, E. Lira, H. H. Kristoffersen, P. Huo, R. Bechstein, E. Lægsgaard, F. Besenbacher, B. Hammer, S. Wendt, Phys. Rev. Lett. 109, 155501 (2012).
[3] H. H. Kristoffersen, J. Ø. Hansen, U. Martinez, Y.Y. Wei, J. Mathiessen, R. Streber, R. Bechstein, E. Lægsgaard, F. Besenbacher, B. Hammer, S. Wendt, Phys. Rev. Lett. 101, 146101 (2013).
[4] S. Wendt, P. T. Sprunger, E. Lira, G. K. H. Madsen, Z. Li, J. Ø. Hansen, J. Matthiesen, A. Blekinge-Rasmussen, E. Lægsgaard, B. Hammer, F. Besenbacher, Science 320, 1755 (2008).