Deakin University
Browse

File(s) under embargo

On choosing a reference redox system for electrochemical measurements: A cautionary tale

journal contribution
posted on 2024-04-12, 00:50 authored by Angel TorrieroAngel Torriero, S Feldberg, J Zhang, A Simonov, A Bond
The potential of a quasi-reference electrode can be determined by introducing an internal reference redox system (IRRS) which comprises either the oxidizable or reducible form of a reversible (and, ideally, outer-sphere) redox couple and then observing the cyclic voltammetric responses. The objective is to choose the IRRS so that the cyclic voltammetric response for the simultaneously present electroactive analyte system (ANS) can be observed independently of the IRRS response. We identify three fundamental paradigms describing the relative positioning of the IRRS and ANS on the potential scale, the operative redox components for the IRRS and ANS, and the starting potential (E start), reversing potential (E rev), and ending potential (E end) for the cyclic voltammetric scan as follows: paradigm A, an optimal paradigm which can produce completely independent cyclic voltammetric responses for the IRRS or for ANS; paradigm B, a less-than-optimal paradigm which can produce an independent cyclic voltammetry (CV) response for the ANS or a mixed response for the IRRS with that response on top of the ANS response; paradigm C, a problematic paradigm that can produce an independent CV response for the IRRS or a mixed response for the ANS with that response on top of the IRRS response; and any mixed response produces a thermodynamically favored redox cross-reaction which couples the IRRS and ANS systems and which can complicate the analysis of the ANS and IRRS responses. The conclusion is that paradigm C is to be avoided.

History

Journal

Journal of solid state electrochemistry

Volume

17

Pagination

3021 - 3026

Location

Berlin, Germany

ISSN

1432-8488

eISSN

1433-0768

Language

eng

Notes

DECEMBER

Publication classification

C1 Refereed article in a scholarly journal

Copyright notice

2013, Springer