Nanoscale structural changes upon electro-oxidation of Au(111) as probed by potentiodynamic scanning tunneling microscopy

Abstract : Understanding the surface structural changes associated with, and resulting from, the electrochemical formation and removal of oxide films is of broadbased practical as well as fundamental importance. These reports chiefly involve STM imaging at a series of fixed potentials, either before and after voltammetric formation and removal of oxide layers, or additionally at suitable high electrode potentials so that surface oxide is present. Evident are several characteristic oxide-induced changes in surface morphology, including the formation of monolayer pits and related metal corrosion, disordering, and roughening. Of the monolayer pits and related metal corrosion,disordering, and roughening. Of the unanswered questions, a central issue concerns the links between surface structural changes and the much discussed voltammetric features for the initial oxidation of ordered gold electrodes.