Stepping beyond cyclic voltammetry: Obtaining the electronic and structural properties of electrified solid–liquid interfaces

Abstract

Classical electrochemical methods such as cyclic voltammetry and current–voltage measurements provide a limited description of what is actually happening at the electrified solid–liquid interface. The ongoing challenges include obtaining insights into the chemical and electronic state of redox-active species and the electrostatic potential across the interfacial region. Here, we provide an overview of recent advances employing electroactive ferrocene-terminated self-assembled monolayers (Fc SAM) as a spectroscopic molecular probe and model electrified solid–liquid interface for X-ray and ultraviolet photoelectron spectroscopy (XPS/UPS). A key finding is the ability to transfer the Fc SAM electrified solid–liquid interface, essentially intact from the solution environment of electrochemistry to the vacuum environment of XPS/UPS. By doing so, the electrochemical properties can be more readily correlated to the potential-induced electronic and structural changes which gives an overall richer picture into the physicochemical properties of electrified solid–liquid interfaces.