Simulation of square wave voltammetry at hemispherical electrodes: Electrochemically reversible, irreversible and quasi-reversible processes

A general approach is developed for the numerical simulation of square wave voltammetry (SWV) at hemispherical electrodes based on the backward implic it method. The latter is applied to the modeling of electrochemically rever sible, irreversible and quasi-reversible redox couples. Data from the simul ations are analyzed by comparing voltammograms for different hemispherical electrode radii with those for diffusion at uniformly accessible planar ele ctrodes for a range of electrochemical late constants so as to evaluate the qualitative effects of transport regime on the observed voltammetry. Exper imental data are presented fur the oxidation of 4-chloronitrobenzene in dim ethylformamide solution at two disk electrodes of radii 250 and 12.5 mu m. The peak current is recorded over a range of square wave frequencies and co mpared to results calculated from simulation of both planar and hemispheric al electrodes.