Berlin 2018 – scientific programme

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O: Fachverband Oberflächenphysik

O 45: Poster: Solid-Liquid Interfaces - Structure, Spectroscopy, Reactions and Electrochemistry

O 45.11: Poster

Tuesday, March 13, 2018, 18:15–20:30, Poster A

DFT study of halogen adsorbate structures on the (100) surfaces of Ag and Au in an electrochemical environment — •Alexandra Dávila, Lukas Deuchler, Svenja Hövelmann, and Eckhard Pehlke — Institut für Theoretische Physik und Astrophysik, CAU Kiel, Germany

The electrochemical interface between halide containing electrolytes and coinage metal electrodes constitutes an important model system. The chemical potential of the halogen as a function of sample potential, which is crucial for the theoretical description of various processes at the electrode, is in general derived from thermodynamics. Analogously to previous work for halogens/Cu [1] we present a systematic density functional study [2,3] for Cl, Br, and I adsorption on Ag and Au(100). Our DFT calculations include incommensurate adsorbate reconstructions via large unit cells. Differences between the range of stability of equilibrium reconstruction as a function of sample potential as derived from the calculations and the conditions under which the respective structures have been observed experimentally [4] are identified. Furthermore, the atomic structure of the boundary between c(2×2)-Cl adsorption domains on the unreconstructed Au(100) surface have been calculated and are compared to STM images from [5].

[1] I. T. McCrum et al., Electrochim. Acta 173 (2015).

[2] //www.vasp.at. G. Kresse et al., Phys. Rev. B 49, 14251 (1994).

[3] P. Giannozzi et al., J. Phys. Condens. Matter 21, 395502 (2009).

[4] X. Gao et al., J. Phys. Chem. 98 (1994).

[5] Y.- C. Yang et al., Electrochim. Acta 112 (2013).