Formulation of the Diffusion-Controlled Current at Very Small Stationary Disk Electrodes

摘要

An electrochemical tool recently developed is a microelectrode with size comparable with the thickness of the diffusion layer. Advantages of these very small electrodes have already been described. However, the theoretical basis for understanding these electrodes has not been as well established as, for example, for polarography or the rotating disk techniques. We have presented previously (1) an analytical solution for the current in chronoamperometry at the stationary disk microelectrode which differed from the result of digital simulation of Kakihana et al. and of Heinze. Subsequently a mathematical error in this solution was identified and corrected in part by Shoup and Szabo, who also presented a simple semiempirical equation for the current which was obtained from the results of a numerical treatment. This forced a reexamination of our work, which in turn suggested a more general result. The purpose of this communication is to correct the previous error and to provide a general solution for the relation between current and potential in the case of a reversible reaction. THe particularization of this general solution to specific techniques such as chronopotentiometry, linear scan voltammetry, and staircase and square wave voltammetry, will be discussed in subsequent papers. (Author)