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O: Fachverband Oberflächenphysik
O 24: Focus Session: Structure and Chemistry of Metal-Oxide Surfaces I
O 24.4: Vortrag
Dienstag, 13. März 2018, 11:30–11:45, MA 005
The (O12) surfaces of hematite and their interactions with water - a DFT study — •Magdalena Bichler1, Florian Kraushofer2, Zdenek Jakub2, Gareth Parkinson2, and Peter Blaha1 — 1Institute of Materials Chemistry, TU Wien — 2Institute of Applied Physics, TU Wien
Hematite (α-Fe2O3) is abundant all over the world and might be used for several applications, including photo electrochemical water splitting.
We focus our study on the (1-102) surface of hematite (R-cut).For this surface two different terminations exist. On the one hand, there is a (1x1) bulk terminated stoichiometric surface, but at low O2 pressure, a (2x1) reconstruction with missing oxygen atoms is formed.1,2
We carried out ab initio calculations by using the WIEN2k code3. Based on our DFT calculations, we present a new model of the (2x1) reconstruction, which is energetically more stable than the one that has been proposed so far4 and agrees well with experiment (including STM simulations).
We also present our results of water adsorption on both surface terminations, including a (1x3) superstructure for water on the bulk terminated surface and discuss these data together with experimental findings.
1 M. A. Henderson et al., Surf. Sci. 1998, 417, 66-81
2 F. Kraushofer et al., JPCC, 2017, accepted
3 http://www.wien2k.at
4 M. A. Henderson, Surf. Sci. 2010, 604 1197-1201