Water adsorption at metal surfaces: A first-principles study of the p(sqrt(3)x sqrt(3))R30° H2O bilayer on Ru(0001)
(2005) Physical review. B, Condensed matter and materials physics —
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- Abstract
- In the light of recent intensity-voltage low energy electron diffraction sLEED-IVd experiments fSurf. Sci. 316, 92 s1994d; Surf. Rev. Lett. 10, 487 s2003dg, the electronic and geometric structure of a water bilayer adsorbed at the Rus0001d surface are investigated through first-principles total energy calculations, using periodic slab geometries and gradient-corrected density functional theory sDFTd. We consider five possible bilayer structures, all roughly consistent with the LEED-IV analysis sthree intact structures and two half- dissociatedd, and a water single layer at Rus0001d. Adsorption energies and substrate-adsorbate geometry parameters are given and discussed in the light of the experiments. We also give a comparative analysis of the electron density redistribution sDrd and of the dipole moment change sDmd induced by water adsorption on the Rus0001d surface. In agreement with Feibelman fScience 295, 99 s2002dg, the half-dissociated structures are found to be more stable than the intact ones, and their adsorption geometries in better agreement with the LEED-IV data. However, the Dr analysis shows that a half-dissociated structure induces a Dm.0, which would be incompatible with the experimentally measured decrease of the work function following bilayer adsorption; the latter would be consistent, instead, with the Dm,0 induced by the intact structures. It is the aim of this paper to compare various possible adsorption structures, most of them already considered previ- ously, with one and the same method. For this purpose, thick slabs and restrictive computational parameters are chosen to generally address the accuracy and the limits of DFT in reproducing adsorption energies and bond lengths of water-metal interacting systems.
- Affiliations
University of Milan
Citations
Materzanini, G., Tantardini, G. F., Lindan, P. J. D., & Saalfrank, P. (2005). Water adsorption at metal surfaces: A first-principles study of the p(sqrt(3)x sqrt(3))R30° H2O bilayer on Ru(0001). Physical review. B, Condensed matter and materials physics. https://hdl.handle.net/2078.5/26799