Modelling reversible cyclic voltammetry at the one-dimensional junction established by three phases: an organic liquid containing a neutral electroactive solute, an aqueous electrolyte solution, and an electronic conductor

Abstract

Scholz et al. (Electrochem. Commun. 2 (2000) 112) recently performed cyclic voltammetry on droplets of a solution of decamethylferrocene (dmfc) in nitrobenzene (nb) lying between graphite and an aqueous solution of potassium chloride. Those authors hypothesized that the reaction dmfc(nb)+Cl −(aq)→dmfc +(nb)+Cl −(nb)+e − took place at the hoop where the three phases meet. We have modelled this hypothesis on the basis that the cyclovoltammetric current is controlled by Nernst’s law and by the cylindrical diffusion of dmfc to, and of dmfc +Cl − from, the three-phase junction. Model and experiment do not match.