Correction factors for the analysis of voltammetric peak currents measured using staircase voltammetry

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Vol. 758; pp. 1 - 6
• Main Authors: Batchelor-McAuley, Christopher, Yang, Minjun, Hall, Elise M., Compton, Richard G.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2015
• Subjects: Diffusion coefficient; Electrochemistry; Electron transfer kinetics; Randles–Ševčík equation; Randles–Ševčík equation; Electrochemistry; Electron transfer kinetics; Diffusion coefficient
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/j.jelechem.2015.10.004

The use of staircase voltammetry for the measurement of reversible diffusional redox species under a linear mass-transport regime leads to significant suppression of the peak currents (up to 20% for larger step sizes) and an increase in the peak-to-peak separation (cf. ∆Epp~70mV at the reversible limit as opposed to 57mV). These discrepancies between the voltammetric results of a staircase and true analogue voltammogram may lead to mis-interpretation of data. This work provides an overview of the differences between the two techniques in the macro-electrode reversible limit and provides new expressions which allow the peak current of a staircase voltammogram to be quantitatively analysed. Moreover, clear guidance is provided about which conditions the application of the provided equation is valid in the terms of mass-transport edge effects to the macro-electrode. •Staircase voltammetry of reversible species is sensitive to the step potential.•Large step sizes lead to smaller peak currents and larger peak-to-peak separations.•Expressions are provided allowing the quantitative analysis of staircase voltammetry.•‘Edge’ effects only need to be considered for cases where dimensionless σ<3350.