Molecular-scale insights into the electrical double layer at oxide-electrolyte interfaces.

Area of Science:

• Materials Science
• Electrochemistry
• Computational Chemistry

Background:

• The electrical double layer (EDL) at metal oxide-electrolyte interfaces is crucial for water splitting, batteries, and corrosion.
• Limited microscopic understanding of the EDL hinders control over these interfacial processes.

Purpose of the Study:

• To unravel the molecular-scale picture of the EDL at the anatase TiO2-electrolyte interface.
• To investigate the influence of pH on EDL structure and properties.

Main Methods:

• Ab initio-based machine learning potential simulations.
• Incorporation of long-range electrostatics.
• Large-scale simulations capturing water dissociation and proton transport.

Main Results:

• Detailed molecular-scale structure of the EDL at the TiO2-electrolyte interface.
• Distinct EDL charging mechanisms on negative and positive surfaces.
• Larger EDL capacitance under basic conditions due to higher cation affinity.

Conclusions:

• Simulation results provide unprecedented insights into EDL structure and behavior.
• Findings are validated by agreement with experimental EDL capacitance data.
• Enhanced understanding facilitates control over interfacial processes in energy applications.