title: Conductance maps by electrochemical tunneling spectroscopy to fingerprint the electrode electronic structure.
abstract: We describe a methodology to perform reliable tunneling spectroscopy in electrochemical media. Sequential in situ tunneling spectra are recorded while the electrochemical potential of the electrode is scanned. Spectroscopic data are presented as conductance maps or conductograms that show the in situ electronic structure of an electrode surface while it undergoes an electrochemical reaction. The conductance map or conductogram represents the redox fingerprint of an electrode/liquid interface in a specific medium and can serve to predict its electrochemical behavior in a quantitative energy scale. The methodology is validated studying the reversible oxidation and passivity of an iron electrode in borate buffer, and we describe the main quantitative information that can be extracted concerning the semiconducting properties of the Fe passive film. This methodology is useful to study heterogeneous catalysis, electrochemical sensing and bioelectronic systems.
authors.affiliation: Laboratory of Electrochemistry and Materials (LCTEM), Department of Physical Chemistry, University of Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain.
authors.forename: Ismael
authors.initials: I
authors.lastname: Díez-Pérez
authors.forename: Aleix G
authors.initials: AG
authors.lastname: Güell
authors.forename: Fausto
authors.initials: F
authors.lastname: Sanz
authors.forename: Pau
authors.initials: P
authors.lastname: Gorostiza
mesh_terms: D004563:Electrochemistry; D004566:Electrodes; D004581:Electronics / Q000295:instrumentation* / Q000379:methods*; D010084:Oxidation-Reduction; D013057:Spectrum Analysis / Q000295:instrumentation* / Q000379:methods*