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

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 E L = 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) À3NaOH at a 60 ppi reticulated vitreous carbon electrode (RVC).

The limiting current for reduction of ferricyanide ion at nickel: The importance of experimental conditions

“…The electrode was degreased with acetone, washed with double-distilled water, and polarized cathodically to evolve hydrogen at 10 mA cm 22 in the background electrolyte for 10 min before each experiment. To minimize the reformation of oxides on the nickel surface, a concentrated solution of K 3 Fe III (CN) 6 and K 4 Fe II (CN) 6 was injected into the electrolyte, such that the final electrolyte contained the desired concentration of ferricyanide ion. Where required, ferricyanide ion concentration was measured using UV-visible spectroscopy on a diode-array spectrophotometer (Hewlett Packard 8452A) that was calibrated using standardized solutions and a k max of 302 nm.…”

“…3 Its determination has been a subject of much discussion, and several methods to assure its correct evaluation have been proposed. [4][5][6] Typically, mass transport measurements include identification of the limiting current plateau region on a steady state, current vs. potential curve of the type shown in Figure 1, obtained by linear sweep voltammetry. The curve shows three zones: the mixed control region where the primary reaction is controlled by both mass transport and electron transfer; the plateau region where the primary reaction is under complete mass transport control, and the final section where a secondary reaction (typically hydrogen evolution) occurs at the same time as the primary reaction.…”

A Novel Method for Limiting Current Calculation in Electrodialysis Modules

“…For this reason, the derivative method [17] was used in this work. Up to now, it has been applied mainly in electrolysis field, but authors' recent work [21] proved that it was appropriate and accurate also for electrodialysis.…”

“…Another method for the determination of limiting current density is the evaluation of derivative dI/dU plotted against the electric current I. The limiting current can be found as the value of current when dI/dU equals zero [17].…”

Chronopotentiometric study of a Nafion membrane in presence of glucose

“…2a), followed by the third region of rapid current increase (current higher than 2 mA). The second region is known as "plateau" and permits, by using the Cowan method [51] to obtain the value of the limiting current density, i L , under each experimental condition. Cowan diagram is a reliable method to determine the value of the current limit when the plateau of the corresponding V-I curve is few defined, as in the studied cases [51].…”