Modulation of Interfacial Water at Gas–Liquid–Solid Interface for Water Electrolysis

Renewable electricity-driven water electrolysis stands at the forefront of clean hydrogen production, playing a crucial role in achieving a net-zero carbon future. Interfacial water is fundamental to this process, dictating reaction kinetics, proton and electron transfer dynamics, and mass transport at the electrode-electrolyte interface. Effective tuning of the structure of interfacial water is imperative for enhancing catalytic activity, efficiency, and long-term stability. As the primary reaction zone for water electrolysis, the gas-liquid-solid interface hosts a well-defined electrical double layer, whose characteristics are shaped by the structuring and evolution of interfacial water. Given its profound impact on electrochemical performance, a fundamental understanding and a controlled modulation of interfacial water have become critical topics in electrocatalysis, motivating the development of this comprehensive review. First, this review introduces the role of interfacial water in water electrolysis, focusing on water molecules arrangement at the interface and its impact on proton and electron transfer processes. Subsequently, various modulation strategies aimed at optimizing interfacial water dynamics for enhanced electrocatalytic performance are systematically examined. Recent progress in understanding the hydrogen-bonding network based on in situ characterization techniques is also highlighted. Finally, we provide a critical discussion on current challenges and future perspectives in this field.