Electroreduction of hexacyanoferrate(III) anions on electrochemically polished Cd(0 0 0 1) plane

Abstract

Electroreduction of hexacyanoferrate(III) anion on an electrochemically polished Cd(0 0 0 1) plane in aqueous KF solutions with different additions of K 3[Fe(CN) 6] was studied by rotating disc voltammetry. The rate of electroreduction of [Fe(CN) 6] 3− depends on the electrode potential and base electrolyte concentration. The kinetic current densities obtained have been used for the determination of the rate constant values for the heterogeneous electroreduction reaction of the [Fe(CN) 6] 3− anion on the Cd(0 0 0 1) plane. The diffuse layer potential values ψ d calculated according to the Gouy–Chapman–Grahame (GCG) model have been used for the construction of the corrected Tafel plots, which were linear in the limited region of negative potentials (−1.35 V ≤ ( E− ψ d) ≤ −1.15 V versus Hg|Hg 2Cl 2|4 M KCl) giving the apparent transfer coefficient value α app≈0.35 for 1×10 −3 M KF solution.