Dresden 2017 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 35: Solid-Liquid Interfaces: Reactions and Electrochemistry - Theory I

O 35.3: Vortrag

Dienstag, 21. März 2017, 12:45–13:00, HSZ 101

Metallic nanoparticles under realistic electrochemical conditions — •Nicolas G. Hörmann, Oliviero Andreussi, and Nicola Marzari — Theory and Simulation of Materials (THEOS), and National Centre for Computational Design and Discovery of Novel Materials (MARVEL), EPFL, CH-1015 Lausanne, Switzerland

We present a study of the stability and equilibrium shape of metallic nanoparticles in electrochemical environments based on periodic density functional theory (DFT) calculations. Metallic surfaces in water are modelled within the self-consistent continuum solvation scheme (SCCS) [2] as recently implemented in the ENVIRON module of Quantum-ESPRESSO [3]. We analyse in detail the effect of the dielectric environment and different adsorbates on surface structure, energetics and potential. The effects of applied potential are treated by studying appropriately charged systems, with explicit countercharge layers in the solution to mimic the effects of the electrical double layer [4]. We will also discuss the difference between this approach and the widely applied “computational hydrogen electrode”[5] with respect to surface termination and adsorbate species. Our results shed light on how to apply ab-initio thermodynamics in electrochemical environments.

[1] A. Jain et al., APL Materials 1, 011002 (2013); [2] O. Andreussi, et al., J. Chem. Phys. 136, 064102 (2012); [3] P. Giannozzi, et al., J. Phys.: Condens. Matter 21, 395502 (2009); [4] N. Bonnet, et al., Phys. Rev. Lett. 110 086104 (2013); [5] J. K. Norskov, et al., J. Phys. Chem. B 108 17886 (2004);