Nanoscale Structure and Dynamics of Water on Pt and Cu Surfaces from MD Simulations

AC Antony and T Liang and SB Sinnott, LANGMUIR, 34, 11905-11911 (2018).

DOI: 10.1021/acs.langmuir.8b02315

The interaction of liquid water with Pt(111) is investigated with classical molecular dynamics (MD) simulations, where the forces are determined using the third-generation charge optimized many-body (COMB3) interatomic potential. In cases of sub-monolayer water coverage, the parameterized eirical potential predicts experimentally observed and energetically favorable root 37 and root 39 reconstructed water structures with "575757" di-interstitial defects. At both sub-monolayer and multilayer water coverages, the structure of the first wetting layer of liquid water on Pt(111) exhibits a characteristic distribution where the molecules form two distinct buckled layers as a result of the interplay between water-metal adsorption and water-water hydrogen bonds. The dynamic spreading rate of water nanodroplets on large Pt surfaces (>200 nm(2)) characterized by molecular kinetic spreading theory is an order of magnitude slower than the molecular kinetic rate of the same droplet on close-packed Cu surfaces due to variation in molecular distributions at the water-metal interface. These nanoscale MD simulation predictions using the COMB3 interatomic potential demonstrate the capability of capturing both many-body interactions between H2O and Pt or Cu and hydrogen bonding in liquid water.

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