DOUBLE POTENTIAL STEP CHRONOAMPEROMETRY AND RELATED PULSE TECHNIQUES AT SPHERICAL ELECTRODES

A theory for double potential step chronoamperometry and related pulse techniques (normal pulse polarography, reverse pulse polarography, differential pulse polarography and differential normal pulse polarography) has been developed for a general electrode model which embraces, among others, four kinds of electrode models, namely, stationary plane, stationary sphere, expanding plane and expanding sphere. Equations for reversible processes which consider the cases where the reduction product dissolves both in the electrolyte solution and in the electrode have been derived. The characteristics of the double step chronoamperometric response at spherical electrodes reveal that the influence exerted by the sphericity of the electrode may be very strong, especially for long pulse durations.