Visualization of Ionic-Liquid/Solid Interfaces by Frequency Modulation Atomic Force Microscopy

Abstract

Solvation structures on liquid/solid interfaces are essential for understanding the mechanisms of various electrochemical reactions. Here, we demonstrate structural analysis on interfaces of ionic liquids (ILs) and electrodes by frequency modulation atomic force microscopy (FM-AFM). A quartz-based force sensor was used instead of a Si cantilever in order to achieve highly-stable and highly-sensitive measurement in ILs. Two-dimensional (2D) force mapping was performed with control of the electrode potential. The potential-dependent solvation structures on the interface were investigated and structural change of the solvation layers was successfully imaged.