The structure of the water/Pt(111) interface has been a subject of debate over the past decades. Here, we report the results of a room temperature molecular dynamics study based on neural network potentials, which allow us to access long time scale simulations while retaining ab initio accuracy. We find that the water/Pt(111) interface is characterized by a double layer composed of a primary, strongly bound adsorption layer with a coverage of ML, which is coupled to a secondary, weakly bound adsorption layer with a coverage of ML. By studying the order of the primary adsorption layer, we find that there is an effective repulsion between the adsorbed water molecules, which gives rise to a dynamically changing, semi-ordered interfacial structure, where the water molecules in the primary adsorption layer are distributed homogeneously across the interface, forming frequent hydrogen bonds to water molecules in the secondary adsorption layer. We further show that these conclusions are beyond the time scales accessible to ab initio molecular dynamics.
Is the water/Pt(111) interface ordered at room temperature?
Note: This paper is part of the JCP Special Topic on The Chemical Physics of the Electrode–Electrolyte Interface.
August E. G. Mikkelsen, Jakob Schiøtz, Tejs Vegge, Karsten W. Jacobsen; Is the water/Pt(111) interface ordered at room temperature?. J. Chem. Phys. 14 December 2021; 155 (22): 224701. https://doi.org/10.1063/5.0077580
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