Charge trapping at the step edges of TiO2 anatase (101)

M. Setvin, X. Hao, B. Daniel, J. Pavelec, Z. Novotny, G. S. Parkinson, M. Schmid, G. Kresse, C. Franchini, U. Diebold

Institut für Angewandte Physik, Technische Universität Wien, 1040 Wien, Austria
Faculty of Physics and Center for Computational Materials Science Universität Wien, 1090 Wien, Austria
Institute of Physics, Academy of Sciences of the Czech Republic, 16200 Prague, Czech Republic

Angew. Chem. Int. Ed. 53 (2014) 4714-4716

A combination of photoemission, atomic force, and scanning tunneling microscopy/spectroscopy measurements shows that excess electrons in the TiO2 anatase (101) surface are trapped at step edges. Consequently, steps act as preferred adsorption sites for O2. In density functional theory calculations electrons localize at clean step edges; this tendency is enhanced by O vacancies and hydroxylation. The results show the importance of defects for the wide-ranging applications of titania.

Corresponding author: Ulrike Diebold (diebold at iap_tuwien_ac_at).

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There is also a version in German: Angewandte Chemie 126 (2014) 4804-4807.