The Theory and Applications of Dual Dynamic Voltammetry with Rotating Ring-Disk Electrodes

The rotating ring-disk electrode (RRDE) is a common example of generator-collector assemblies made up of two electron conducting components: the ring (collector) surrounding the centrally located disk (generator). The operating principle of RRDEs is that products of the disk electrode reaction - the rate of which may be influenced by rotation - move to the ring by forced convection, where they participate in an additional electrochemical reaction and will thus be detected. In contrast to classical RRDE experiments, where potentiostatic control is applied to at least one of the electrodes, new techniques were developed in the past decade that utilized dynamic potential control of both electrodes at the same time. The method of "dual dynamic voltammetry" (DDV) has since been applied to study the mechanism of electrochemical processes from electrocatalytic reactions involving dissolved species (such as oxygen reduction) to the study of metal corrosion and polymer degradation phenomena. This paper reviews the basics of the DDV method and some of its possible applications.