Potential Dependent Evolution of Electric Double Layer at Electrode/Water Interface

Abstract

Water structure at electrode interface can affect electrochemical reactions in multiple ways, as it plays important role in processes including mass transport, surface adsorption, and charge transfer. Thus, in-situ characterization of electrode/water interface is in high demand for a deeper understanding and better utilization of electrochemical systems. Here, we introduce our study on the evolution of interfacial water structure with changing electric potential. Configurational and structural understanding were obtained by in-situ Raman spectroscopy and atomic force microscopy (AFM) measurements respectively, with special efforts to enhance interfacial sensitivity for both techniques. Our study demonstrated electric potential dependent changes in the hydrogen bonding network and hydration layer structure, which provides new insight into how interfacial hydration structure can be correlated with the electrochemical reaction performance.