Rotating Disk and Rotating Cylinder Electrode Setups (RDE and RCE)

A potentiostat may be used in conjunction with an electrode rotator (e.g., Pine Research MSR Modulated Speed Rotator (MSR) or WaveVortex 10 WaveVortex 10 Electrode Rotator models) to perform Rotating Disk Electrode (RDE) or Rotating Cylinder Electrode (RCE) experiments.  These experiments are hydrodynamic variations of traditional three-electrode voltammetry. Three-Electrode Setups Rotating the working electrode (which may have a disk or cylinder geometry) at a controlled rate establishes convective mass transfer of electrolyte solution (and dissolved electroactive species) towards the electrode surface.  Connecting the potentiostat to a hydrodynamic experiment involves not only making connections to the electrodes (working, counter, and reference) but also providing a rotation rate control signal to the electrode rotator.

 

The potentiostat cell cable can be used for these hydrodynamic experiments by making similar connections as those used in typical three-electrode cells. Three-Electrode Setups On a Pine Research WaveDriver potentiostat, WaveDriver 100 EIS Potentiostat the GREEN lead (counter electrode drive) is connected to the counter electrode, and the WHITE lead (reference electrode sense) is connected to the reference electrode.  Connections of the RED and ORANGE leads (working electrode drive and sense) to the rotating working electrode are typically made via spring-loaded brush contacts which push against the shaft of the rotating electrode.

 

As an example of how connections are made to a rotating disk or cylinder electrode, consider the brush contacts on the popular Pine Research MSR rotator system Modulated Speed Rotator (MSR) (see Figure 1).  This rotator system features two pairs of opposing brushes on either side of the rotating shaft.  The upper pair of brush contacts (RED) is used to make electrical contact with a rotating disk or cylinder electrode mounted in the rotator.  The RED and ORANGE cell cable leads (working electrode drive and sense) should be stacked together and connected to the upper pair of brush contacts.  Note that for the Pine Research MSR Rotator, it is also common practice to use a short banana cable to connect opposing brushes (see Figure 1, right).  This practice may or may not improve the signal-to-noise ratio of the experimental data; some trial-and-error is normally required to determine optimal cable configuration.

 

 

A second example of rotating working electrode connections is shown in Figure 2 for the newer Pine Research WaveVortex 10 rotator system. WaveVortex 10 Electrode Rotator Unlike the MSR rotator, the WaveVortex 10 only contains one brush contact per electrode connection, meaning there are only two banana posts (compared with four on the MSR).  Similarly to the MSR connection, the RED and ORANGE cell cable leads (working electrode drive and sense) should be stacked together and connected to the left (RED) banana post on the WaveVortex 10 that corresponds to the disk electrode (see Figure 2).  Note that the WaveVortex 10 rotator may only be used for RDE or RRDE experiments; it cannot be used for RCE studies.