Transient Response under Nonideal Potential Control: I . Reversible Charge Transfer Reaction

An analysis is presented of the response of a reversible charge transfer reaction at a solid/electrolyte interface to a damped oscillatory controlled potential. This control function is of the type that results at short times upon imposition of a potential step using a typical potentiostat. We show that the current always overshoots the ideal response and that the period over which the observed current deviates significantly from the ideal behavior depends upon the size of the potential step, the interfacial capacitance, and the characteristics of the potentiostat. In any event, constant potential control is not established until four or five dimensionless times, , have elapsed after imposition of the potential step, where is the exponential decay constant for the oscillations in the imposed control function.