The influence of migration on cyclic and rotating disk voltammograms

Standard methods of analysis based on the dependence of current magnitudes and waveshapes on scan rate (cyclic voltammetry) and rotation rate (rotating risk electrode voltammetry) are available to interpret processes of the form Az+⇌E°f,ks,αA(z+n)++ne− when the migration current is negligible. Using analysis of simulated voltammograms, the present study shows that when a migration current is present, it simply acts as a scaling factor with respect to current magnitudes and introduces a small potential shift. The effects are equivalent to altering the diffusion coefficient in the fully supported case. Experimental detection of migration can be confirmed by examining the concentration dependence of a process, but not by dependence on scan rate or rotation rate.