Probing water-electrified electrode interfaces: Insights from Au and Pd

Area of Science:

• Physical Chemistry
• Surface Science
• Computational Materials Science

Background:

• The water/electrode interface is crucial for electrochemistry but challenging to model at the atomic scale.
• Out-of-equilibrium phenomena at interfaces require sophisticated theoretical treatments.

Purpose of the Study:

• To investigate the influence of an applied bias potential on water adsorbed on metallic electrodes (Au(111) and Pd(111)).
• To compare the structural and electronic responses of water on different metal surfaces under bias.

Main Methods:

• Combined approach using density functional theory (DFT) and non-equilibrium Green's function (NEGF) methods.
• Atomic-scale simulations of water adsorption on Au(111) and Pd(111) under an external bias.

Main Results:

• Both Au and Pd electrodes induce qualitatively similar structural changes in adsorbed water molecules.
• Significant quantitative differences in water properties arise due to distinct water-metal bonding characteristics.
• The applied bias influences the water/electrode interface properties.

Conclusions:

• Quantum-mechanical modeling is essential for accurately describing electrochemical interfaces.
• The choice of metal electrode significantly impacts the quantitative behavior of adsorbed water under bias.