Voltage-dependent nanomechanical mapping at the solid–liquid interface

Abstract

Electrochemistry plays a role in green technologies such as catalysts, batteries, hydrogen production and photovoltaics. It is greatly influenced by local effects at the solid-liquid region, importantly electric double layers. Past research shows that atomic force microscopy is a suitable method for studying these inhomogeneous local effects. Our goal is to develop an experimental and data analysis method for studying these systems.

This thesis demonstrates EC-AFM measurements in PFT-mode, with a custom electrochemical cell filled with H2SO4 electrolyte, on a normal pulse voltammetry potential-controlled gold substrate. Data analysis of the force spectroscopy shows a clear dependency of the forces on the potential. Average force curves highlight the numerical values, and force curve maps show reproducible spatially inhomogeneous potential dependence of the adhesion. Deviations in the adhesion appear at potentials that are in literature associated with sulfate and oxide adsorption.