Mass-Transfer Admittance Voltammetry from Electrochemical Impedance Spectroscopy and Its Applications

Abstract

We report an extraction-reconstruction strategy for obtaining a novel voltammogram for a specific electrochemical process. While a conventional voltammogram is obtained from potentiodynamic currents, our voltammogram is obtained from a large body of potentiodynamic electrochemical impedance spectra by taking advantage of their highly resolvable power. As a proof of concept, construction of a mass transfer admittance voltammogram (MTAV) is demonstrated, which is made up of purely mass transfer admittances plotted vs. potential, excluding effects from other interfering electrochemical components. We also compare the MTAV with the AC voltammogram to show its enhanced accuracy and apply the novel voltammetry to clearly determine the number of electrons transferred and diffusion coefficients, which may vary depending on experimental conditions, for a complex electrochemical reaction.