Temporal and Spatial Insights into Electric Double Layer Structures and Their Interfacial Polarization Responsiveness on Metal-Water Interfaces

Resolving the microscopic structure of the electric double layer remains a significant challenge. To overcome this, we developed a temporal-spatial perspective analytical framework using constant-charge ab initio molecular dynamics simulations, enabling quantitative assessment of the coupling between the interfacial water structure and interfacial polarization response. Four metals, Au, Ag, Cu, and Pt, were selected to systematically probe how intrinsic metal affinities regulate interfacial water organization. The simulations reveal that these metal surfaces induce hydrogen bond networks ranging from loose-disordered to compact-highly ordered, yielding different polarization behaviors. The Ag–H 2 O interface maintains cooperative polarization while allowing orientational reconfiguration, resulting in the highest interfacial polarization sensitivity. In contrast, the Au-, Cu-, and Pt–H 2 O interfaces exhibit suppressed tunability due to overly loose or dense hydrogen bond structures. Through systematic comparison, we propose a structure-dynamics cooperative balance mechanism, in which interfacial polarization responsiveness is jointly governed by the dynamic fluctuations of water molecules and the spatial continuity of the hydrogen bond network. This framework offers a new theoretical basis for deepening the microscopic understanding of the electric double layer and guiding interfacial modulation.