Redox mediation at poly(o-aminophenol) coated electrodes: mechanistic diagnosis from steady state polarization curves

Gabriel Ybarra,Carlos Moina,María Inés Florit,Dionisio Posadas

doi:10.5599/jese.582

Abstract

In this work, the mediated reduction of Fe(CN)63- and Fe3+ in poly(o-aminophenol) coated electrodes is analyzed by means of a diagnosis diagram based on the features of the steady state current-potential curves. This analysis allows to identify the current determining process and to reproduce the experimental characteristics of the polarization curve from the relevant kinetic and thermodynamic parameters with a minimum amount of experimental measurements.

Highlights

Redox mediation is a process of indirect electron transfer between a redox species in solution and an electrode with the necessary participation of a third actor, a redox mediator [1,2,3,4,5]
We will denominate case R to the conditions in which the electron transfer at the polymer-solution interface is the current determining process (c.d.p.), case E to the one which is controlled by slow charge transport in the film, and case D to the one which is determined by slow mass transport in the solution
Only the cathodic wave, which corresponds to the reduction of Fe(CN)63, can be observed in PAP coated electrodes and it is displaced towards more negative potentials when compared to the naked electrode

Summary

Introduction

Redox mediation is a process of indirect electron transfer between a redox species in solution and an electrode with the necessary participation of a third actor, a redox mediator [1,2,3,4,5]. We have presented elsewhere [1] a model based on previous treatments [16,17] to analyze current-potential curves of redox mediation at redox polymers coated electrodes.

Results

Conclusion