Tuning water dissociation at oxide-electrolyte interfaces with electric fields

• 成果类型: Article
• 署名作者: Zhang, Chunyi; Yu, Zheng; Car, Roberto; Selloni, Annabella
• 署名单位: Princeton University; Eastern Institute of Technology, Ningbo
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-12180
• DOI: 10.1073/pnas.2505929122/-/DCSupplemental
• 发表日期: 2025-08-26
• 关键词: surface-protonation; photocatalysis; energy; rutile; mechanisms; catalysis

摘要

Understanding how electric fields influence water dissociation at heterogeneous interfaces is crucial for controlling interfacial chemical reactions and advancing next-generation energy technologies. Herein, ab initio-based machine learning simulations show that even small electric field changes can significantly alter the water dissociation fraction at planar TiO2-electrolyte interfaces. The resulting free energy difference between undissociated and dissociated interfacial water exhibits a linear dependence on the field change with a slope of 1.97 e angstrom, which far exceeds the dissociation-induced dipole change of a water molecule. Employing a machine-learned collective variable to investigate the reaction statistics of thousands of water dissociation/recombination events, we find that small electric field changes exert minor effects on individual reaction energy barriers but significantly influence the populations of local configurations associated with initial states that are most favorable for reactions. These findings elucidate the pronounced impact of electric fields on interfacial water dissociation and reveal a mechanism for electric-field-controlled chemical reactions.