First-Principles Molecular Dynamics with Potential and Charge Fluctuations Applied to Au(111) in Alkaline Solutions

Area of Science:

• Computational chemistry
• Physical chemistry
• Materials science

Background:

• Electrified solid-liquid interfaces are vital for energy technologies, but simulations struggle to match experimental data.
• Accurate modeling of these interfaces is key for advancing energy conversion, storage, and sensing.

Purpose of the Study:

• Introduce the Fluctuation-Dissipation Theorem-Solvated Jellium Model (FDT-SJM) for ab initio molecular dynamics.
• Enable simulations of electrode potential effects on interfaces with improved experimental correlation.

Main Methods:

• Developed FDT-SJM within the GPAW DFT code for potential-controlled simulations.
• Electrode charge fluctuates based on the fluctuation-dissipation theorem (FDT).
• Employed the solvated jellium method (SJM) for charge screening.

Main Results:

• Validated FDT-SJM by simulating the Au(111) interface in various aqueous solutions (water, KOH, LiOH, Li, K).
• Observed water reorientation correlating with electrode surface charge.
• Successfully estimated interface capacitance and potential of zero charge.

Conclusions:

• The FDT-SJM method provides a robust approach for simulating electrified interfaces.
• Achieved consistency between simulation predictions and experimental data.
• Enhances the predictive power of computational chemistry for electrochemical systems.