Redox mediation at electroactive polymer coated electrodes: Mechanistic diagnosis criteria from steady state polarization curves

A Study of the Charge Transport Process at Nickel Hydroxide-Gold Modified Electrodes employing Rotating Disc Electrode Voltammetry and Ac Impedance Measurements

“…At this point it is interesting to compare D ct c 2 o values obtained in this work for nickel hydroxide films with those obtained for other materials such as electroactive redox polymers that also are able to act as mediators in redox reactions [16][17][18][19][20][21]. In this regard, the electroactive polymer poly(o-aminophenol) immediately synthesized, that acts as mediator in the presence of different electroactive solutes (Fe(CN) 6 4−/3− and hydroquinonebenzoquinone) exhibits a D ct c 2 o value around 7.32 * 10 −14 mol 2 s −1 cm −4 [18].…”

“…(1) was previously employed to describe the charge transport processes in other materials such as electroactive redox polymers that also contain active redox sites and then, these polymers are able to act as mediators in redox reactions [16][17][18][19][20][21]. In Eq.…”

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

“…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. This model considers that any observed current under steady state conditions follows the process schematically shown in Figure 1.…”

“…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]. Redox mediators can be surface immobilized sites which can be oxidized or reduced electrochemically by controlling the potential of the supporting electrode.…”

“…Most of them employ the limiting current obtained in steady state conditions as the only criteria to determine the current determining process. In a previous work [1], we have presented a model, based on the previous work of Laviron [16] and Murray [17], which allows to interpret most of the experimental facts, as well as to elaborate diagnostic criteria from which the kinetic parameters can be estimated. In this work, we show how those diagnostic criteria can be applied to the case of the reduction of Fe(CN)6 3-and Fe 3+ mediated by a redox polymer.…”