Simple Analytical Equations for the Current–Potential Curves at Microelectrodes: A Universal Approach

Abstract

A general, simple, analytical expression for the steady state voltammetric response at electrodes of three different geometries is developed. These geometries have both uniform (isolated microsphere) and nonuniform (microdisc and microsphere supported on an electroinactive surface) accessibility. The expression is applicable over the full range of electrochemical reversibility and for any initial concentrations of both species in the redox couple of interest. By making the assumption that, in all cases, the concentration of each species across the electrode surface is constant (representing an average of the true concentration profile), an equation describing the steady state voltammetric wave is deduced. Although approximate, the developed equation has a high degree of accuracy when compared to simulated results. This method, based on sound physical principles, is open to extension to other geometries and represents an advantage of previous solutions largely restricted to microdiscs.

One electron oxygen reduction in room temperature ionic liquids: A comparative study of Butler–Volmer and Symmetric Marcus–Hush theories using microdisc electrodes

“…al. 54 shows that steady state voltammetry at an isolated spherical electrodes alone in solution, a spherical electrode supported on a conductive but inert surface and a microdisc electrode (all shown schematically in Fig. 6) may all be approximately described (under the Butler-Volmer formalism) by a single equation:…”

Measuring the Electrode Kinetics of Surface Confined Electrode Reactions at a Constant Scan Rate

“…The application of square-wave voltammetry (SWV) [1] for mechanistic and kinetic studies [2][3][4][5][6][7][8] of electrode processes increases permanently in the last decade, due to the intensive development of the theory of the technique for a variety of electrode mechanisms and electrode geometries [9][10][11][12][13][14][15][16][17]. A plethora of intriguing studies has been conducted in relation to the kinetics of charge transfer processes at liquid/liquid interfaces [18][19][20][21][22][23], electrochemistry of immobilized proteins [24,25], and catalytic mechanisms [26][27][28], revealing that SWV is highly suited for both mechanistic and kinetic characterization of electrode reactions, besides its excellent analytical performances [29][30][31][32][33][34] and its appropriateness for bioanalytical applications [35][36][37][38][39][40][41].…”

Insights into the Voltammetry of Cavity Microelectrodes Filled with Metal Powders: The Value of Square Wave Voltammetry

“…where y refers to the y‐th SW cycle (see SI) and to the surface concentration of the oxidized species, which is demonstrated to be only dependent on the applied potential in any pulse p [Eq. ]: [24] …”