Characterization of electrochemical systems using potential step voltammetry. Part II: Modeling of reversible systems

Abstract

This study was carried out to compare the results obtained using potential step voltammetry and linear sweep voltammetry with a rotating gold disc electrode (RDE), when models based on equivalent circuits (EC) were used. The results lead to an equivalent circuit model that allows us to interpret the electrochemical behavior of aqueous solutions containing Fe(CN)6 −4 and Fe(CN)6 −3. With this model, we determined the values of the electrical resistance of the medium (Rs) as well as its polarization resistance (Rp), and established correlations between these values and the kinetic parameters of the system. The proposal highlights the need to introduce a new component for modeling using EC, which we have called the electrochemical diode. © 2019 Elsevier Ltd