Simulation of Electrochemical Oxidation in Aqueous Environments under Applied Voltage Using Classical Molecular...

Area of Science:

• Computational materials science
• Electrochemistry
• Physical chemistry

Background:

• Understanding metal electrode behavior in aqueous environments is crucial for electrochemical applications.
• Previous simulations often prevented charge transfer, limiting realistic modeling.
• Reactive molecular dynamics (MD) offers a pathway to simulate complex interfacial phenomena.

Purpose of the Study:

• To simulate metal electrodes in water under applied voltage using reactive MD.
• To investigate charge transfer effects between metal and water.
• To compare simulation results with experimental data on electrode oxidation and dissolution.

Main Methods:

• Employed reactive MD simulations with third-generation charge-optimized many body (COMB3) potentials and the electrode COMB (eCOMB) approach.
• Modified equations of motion during the charge equilibration step (QEq) to simulate applied voltage.
• Coupled charge transfer between water and metal electrodes via QEq.

Main Results:

• Simulations showed charge accumulation (negative on water, positive on metal) before voltage application.
• Characterized the extent of this charge accumulation and explored mitigation strategies.
• Root mean square deviation plots indicated good agreement between simulated metal surface oxidation and experimental observations.

Conclusions:

• The developed reactive MD approach accurately captures metal electrode oxidation in water.
• Coupled charge transfer is a significant factor in simulating electrochemical interfaces.
• This method provides a valuable tool for studying metal-water interactions under electrical potential.