Characterizing Recast Nafion® Film Electrode Interface Diffusion and Kinetics in a Non-Aqueous System

Abstract

The effect of recast Nafion® films on platinum working electrodes in acetonitrile will be characterized by cyclic voltammetry and rotating disk voltammetry. Until now, the behavior of recast Nafion® in a non-aqueous system has not been reported in this way. The behavior of recast Nafion® films in acetonitrile has been anecdotally observed to be different from the behavior in aqueous solutions, which have also been comprehensively studied1,2. The reversible redox couple of Tris(2,2′-bipyridine)ruthenium(II) hexafluorophosphate, Ru(bpy)3 2 ++, in an acetonitrile electrolyte solution will be compared between a bare platinum working electrode and a recast Nafion® film coated platinum working electrode by cyclic voltammetry. In cyclic voltammetry the convective mass transport of the species is limited only to the diffusion at the stationary electrode interface. In rotating the working electrode (RDE) the limitation on mass transport is extended beyond the stationary diffusion behavior. The current is dependent on and limited by the mass transport of the species to the electrode interface where it can undergo redox, the limiting current of both a bare platinum working electrode system and of a recast Nafion® film coated platinum working electrode will be observed by changing the rotation rate of the RDE. The diffusion interface of the electrode inside an acetonitrile solution of Ru(bpy)3 2 + and an electrolyte will be determined by rotating disk voltammetry at a bare platinum working electrode and at a recast Nafion® film coated platinum working electrode. The film solution interface thickness will be reported along with the effect on the diffusion of the interface between bare and recast Nafion® coated platinum working electrodes.1. S. K. Zecevic et al 1997 J. Electrochem. Soc. 144 29732. T. A. Zowodzinski, S. Gottesfeld et al 1997 Advances in Electrochemical Sciences and Engineering