Structure, Dynamics, and Wettability of Water at Metal Interfaces

Abstract

The water/metal interface often governs important chemophysical processes in various technologies. Therefore, from scientific and engineering perspectives, the detailed molecular-level elucidation of the water/metal interface is of high priority, but the related research is limited. In experiments, the surface-science techniques, which can provide full structural details of the surface, are not easy to directly apply to the interfacial systems under ambient conditions, and the well-defined facets cannot be entirely free from contamination at the contact with water. To answer long-standing debates regarding the wettability, structure, and dynamics of water at metal interfaces, we here develop reliable first-principles-based multiscale simulations. Using the state-of-the-art simulations, we find that the clean metal surfaces are actually superhydrophilic and yield zero contact angles. Furthermore, we disclose an inadequacy of widespread ice-like bilayer model of the water adlayers on metal surfaces from both averaged structural and dynamic points of view. Our findings on the nature of water on metal surfaces provide new molecular level perspectives on the tuning and design of water/metal interfaces that are at the heart of many energy applications.