Probing Water-Electrified Electrode interfaces: Insights from Au and Pd

TL;DR

This study combines DFT and NEGF methods to analyze how external bias affects water molecules adsorbed on Au and Pd electrodes, revealing significant quantitative differences driven by water-metal bonding.

Contribution

It introduces a quantum-mechanical approach to model water-electrode interfaces under bias, highlighting differences between Au and Pd surfaces.

Findings

Both Au and Pd induce similar structural responses in water.

Quantitative differences are driven by water-metal bonding.

Quantum modeling is essential for accurate interface description.

Abstract

The water/electrode interface under an applied bias potential is a challenging out-of-equilibrium phenomenon, which is difficult to accurately model at the atomic scale. In this study, we employ a combined approach of Density Functional Theory (DFT) and non-equilibrium Green's function (NEGF) methods to analyze the influence of an external bias on the properties of water adsorbed on Au(111) and Pd(111) metallic electrodes. Our results demonstrate that while both Au and Pd-electrodes induce qualitatively similar structural responses in adsorbed water molecules, the quantitative differences are substantial, driven by the distinct nature of water-metal bonding. Our findings underscore the necessity of quantum-mechanical modeling for accurately describing electrochemical interfaces.