Strategies for the determination of the convective-diffusion limiting current from steady state linear sweep voltammetry

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Description/Abstract

The limiting current is an important parameter for the characterization of mass transport in electrochemical systems operating under convective-diffusion control. Four methods to determine the limiting current from current (I) vs. potential (E) plots are considered. Strategies to determine the limiting current values include: 1) direct measurement from I vs. E curves, 2) estimation from the current value at EL =DE/2 where DE is the length of the limiting current plateau), 3) evaluation of the first derivative dI/dE in the I vs. E curve and 4) from plots of E/I vs. I-1. The electrode reactions chosen to demonstrate the different strategies are: Cu(II) → Cu(I) and Cu(I) → Cu(0) in 1.5 mol dm-3 NaCl (pH 2) at a platinum rotating disc electrode and K3Fe(CN)6 → K4Fe(CN)6 in 1 mol dm-3 NaOH at a 60 ppi reticulated vitreous carbon electrode (RVC).