A Theoretical Model for Induced Charging Currents in Potentiostatic Chronoamperometry. Applications to Photoelectrochemistry.

摘要

It has been assumed previously that charging current is only significant for electrochemical experiments where the applied potential is varied (e.g., potential step, potential sweep). This paper deals with characterization of charging current contributions to chronoamperometric measurements under potentiostatic conditions, where the charging current is induced by the changing faradaic current. This case corresponds directly to the conditions for chronoamperometric measurements of flash photolytic processes, commonly called photopolarography. A theoretical model applicable to any electrolysis mechanism, and a general method of analysis, are presented to characterize this charging current. In addition, the model is extended to include potential-step chronoamperometry. Application of this model to these two specific cases demonstrates the significance of the charging current term relative to measured current.