Scanning tunneling microscopy and electrochemical response of electrofacetted gold electrodes

Abstract

A first attempt to establish a direct correlation between ex situ scanning tunneling microscopy imaging and voltammetric features of gold electrodes is presented. For this purpose gold microelectrodes, either polyfacetted or electrochemically were used. The STM topography of polyfacetted gold micro- electrodes exhibits flat domains and regions with a number of different defects, whereas that of electrofacetted gold presents a parallel ridge-like structure of a few atoms height together with other types of defects. Lead UPD and voltammetric stripping reactions for the O-electrodesorption reactions both in acid solution were selected as test reactions. The correlation between STM topography and voltammetry data supports qualitatively the assignments made for lead UPD peaks resulting on different gold single crystal surfaces.