Rotating waves on disk and ring electrodes

Abstract

Experimental studies have been carried out with cobalt disk and ring electrodes in buffered phosphate solutions under potentiostatic control with the Haber–Luggin capillary of the reference electrode placed in the centre of the electrode close to the surface.

The applied potential is adjusted to be cathodic with respect to the Flade potential. Visible fronts outlining a propagating wave and characterizing the transition from the passive to the active state of the metal rotate around the tip of the reference electrode while the overall measured current remains almost constant. At applied potentials close to the Flade potential a modulation of the rotating wave and, correspondingly, of the current time curves, is observed.