To wet or not to wet? Dispersion forces tip the balance for water-ice on metals

TL;DR

This study reveals that van der Waals dispersion forces significantly influence water's wetting behavior on metals, with non-local correlations affecting the stability of wetting layers versus bulk ice, challenging previous theoretical predictions.

Contribution

It demonstrates the crucial role of non-local correlation effects in accurately predicting water-metal interactions and wetting layer stability, which were previously underestimated in standard density functional theory.

Findings

Non-local correlations substantially contribute to water-metal bonding.

Dispersion forces influence the relative stability of wetting layers and bulk ice.

Standard DFT functionals often incorrectly predict wetting layer stability.

Abstract

Despite widespread discussion, the role of van der Waals dispersion forces in wetting remains unclear. Here we show that non-local correlations contribute substantially to the water-metal bond and that this is an important factor in governing the relative stabilities of wetting layers and 3D bulk ice. Due to the greater polarizability of the substrate metal atoms, non-local correlations between water and the metal exceed those between water molecules within ice. This sheds light on a long-standing problem, wherein common density functional theory exchange-correlation functionals incorrectly predict that none of the low temperature experimentally characterized ice-like wetting layers are thermodynamically stable.