Characterization of the Capacitance of a Rotating Ring–Disk Electrode
The paper authored by
N. Kovács,
M. Ujvári,
G.G. Láng, P. Broekmann and
S. Vesztergom
is published in Instrumentation Science and Technology (2015, vol. 43, pp. 633–648).
Abstract:
The use of rotating ring–disk electrodes as generator-collector systems has so far been limited to the detection of Faradaic currents at the ring. As opposed to other generator-collector configurations, non-Faradaic detection has not yet been carried out with rotating ring–disk electrodes. In this study, a.c. perturbation based detection for measurement of the ring impedance is introduced. By using a conducting polymer-modified disk electrode in combination with a bare gold ring as a model, it is shown that the measured ring capacitance correlates with the polarization of the polymer film, most probably due to counter-ion exchange. A method of calculating the ring capacitance based on a small-signal sinusoid perturbation is described and the most important instrumental limitations are identified.
