The current density versus potential (

versus
) curve for a redox reaction (

) under steady-state conditions at a rotating disk electrode (RDE) is
Faradaic (

) and electrode (
Z) impedance for the redox electrochemical reaction (E) at a RDE, taking into account the series ohmic resistance

, are given by

,

,

,

,
where

is the angular frequency,

is the charge transfer resistance,

is the mass transport resistance,

is the interfacial double capacitance,

is the time constant of the mass transport,

is the characteristic frequency of the charge transfer, and

is the characteristic frequency of the mass transport.
[1] J.-P. Diard, C. Montella, and B. Le Gorrec,
Cinétique Electrochimique, Paris: Hermann, 1996.
[2] C. Montella, J.-P. Diard, and B. Le Gorrec,
Exercices de Cinétique Electochimique, II Méthodes d'impédance, Paris: Hermann, 2005.
[3] M. E. Orazem and B. Tribollet,
Electrochemical Impedance Spectroscopy, Hoboken: John Wiley & Sons, 2008.