Hidden interfacial electric fields in chemistry: contact electrification and beyond

Area of Science:

• Physical Chemistry
• Surface Science
• Chemical Engineering

Background:

• Chemical reactions occur at interfaces like solid-liquid, gas-liquid, and liquid-liquid.
• Interfacial electric fields, arising from charge transfer and molecular orientation, profoundly alter reaction pathways.
• Contact electrification (CE) at solid-liquid interfaces generates significant fields, impacting radical formation and redox chemistry.

Purpose of the Study:

• To review the role of interfacial electric fields in driving chemical reactions.
• To establish a unified conceptual framework for understanding these fields beyond empirical observations.
• To highlight the need for advanced techniques to resolve field dynamics and reaction outcomes.

Main Methods:

• Review of existing literature on interfacial phenomena and electrochemistry.
• Discussion of cooperative effects generating interfacial electric fields (CE, water dipoles, ion redistribution).
• Analysis of parameters modulating these fields (mechanical excitation, material properties, solution conditions).

Main Results:

• Interfacial electric fields, ranging from 10^6 to 10^9 V m^-1, are crucial for interfacial reactions.
• Dynamic fluctuations of these fields are critical drivers of interfacial chemical reactions.
• Key parameters like pH, ionic strength, and dissolved gases modulate field strength and reactivity.

Conclusions:

• Interfacial electric fields are fundamental forces in chemistry, not just boundary conditions.
• Further research is needed to understand field spatial/temporal dynamics and their reaction-driven evolution.
• Elevating interfacial electric fields to explicit design parameters can enable sustainable and efficient interfacial chemistry.