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Beyond Dielectrics: Interfacial Water Orientational Polarization Governs Graphene-Based Electrochemical Interfaces
Peiyao Wang1,2,3, Gengping Jiang4, Yuan Yan1
1Department of Mechanical Engineering, The University of Melbourne, Parkville, VIC 3010, Australia.
Nano Letters
|July 9, 2025
Summary
Interfacial water polarization significantly impacts electrochemical systems, challenging the traditional view of water as a passive dielectric. This surface-induced effect alters electric potential and capacitance, requiring a revised electric double layer model.
Area of Science:
- Electrochemistry
- Physical Chemistry
- Materials Science
Background:
- Traditionally, water in electrochemical systems is considered a passive dielectric medium.
- The classic electric double layer (EDL) model treats water as a simple dielectric, overlooking its active role.
Purpose of the Study:
- To challenge the conventional perspective of water as a passive dielectric in electrochemical systems.
- To investigate the role of interfacial water polarization in electrochemical systems.
Main Methods:
- Molecular dynamics simulations.
- Theoretical analysis.
Main Results:
- Interfacial water exhibits distinct orientational polarization compared to bulk water.
- Water excessively screens electrostatic potential between ions and surfaces, going beyond the classic EDL model.
- Surface-induced water polarization governs potential distribution, EDL capacitance, and can invert electrode surface potential polarity.
Conclusions:
- Water is not merely a passive dielectric but an active participant in electrochemical interfaces.
- A revised EDL model is proposed, incorporating surface-induced interfacial water polarization for accurate potential distribution.
- This work provides molecular-level insights into interfacial phenomena in electrochemical systems.
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