Ring–disc electrodes. Part 19.—Adsorption studies at low frequency A.C.

Abstract

The theory for the a.c. experiments at a ring–disc electrode when the reactant and product are adsorbed on the electrode is presented. The theory holds for all frequencies of modulation. A theoretical expression for the a.c. impedance at the disc electrode for the same system is also derived. The adsorption of thionine and leucothionine on platinum has been studied using both the ring–disc and a.c. impedance techniques. Experimental results and theory are found to be in good agreement and similar results are obtained from the two different techniques.