Thin and ultra-thin layer dual electrode electrochemistry: Theory of steady-state voltammetry without supporting electrolyte

The electrode system consisting of two closely-spaced plane electrodes oriented parallel to each other was examined. The expressions for the steady-state voltammetric response of the generator electrode in a solution of an electroactive species with no supporting electrolyte have been derived. The theoretical modeling of the mixed diffusional-migrational transport in the thin-layer cells reveals a strong effect of the diffusion coefficient on the magnitude of the steady-state limiting current at communicating electrodes. In general, the form of this dependence is different from that derived for the semi-infinite transport to microelectrodes in the supporting-electrolyte free systems. The limitation of the derived expressions due to the application of the electroneutrality condition at any point in the system has been also examined quantitatively. (C) 2013 Elsevier B.V. All rights reserved.