Square Wave Voltammetry at Small Disk Electrodes: Theory and Experiment

摘要

An equation is derived for the current response of a reversible electron transfer reaction for square wave voltammetry at an embedded disk electrode. Peak shape and position are invariant to the dimensionless parameter (D TAU)/r-sq where D is the diffusion coefficient, Tau the square wave period, and r the radius of the disk, whereas peak current density increases without limit with increasing (D TAU)/r-sq. A simple empirical equation predicts the peak current for any value of (D TAU)/r-sq for square wave amplitude 50/n mV and step height 10/n mV. Experimental results for oxidation of ferrocyanide at small platinum electrodes agree well with the theory and demonstrate the practical utility of the experiment.