Ultrasonic Effects on Electrolysis of MV²⁺ in Surfactant and Polymer Solutions

Abstract

Ultrasonic effects on electrolysis of methyl viologen (MV²⁺) in surfactant and polymer solutions were investigated using an ultrasonic vibrating electrode (USVE). Addition of an anionic polymer or surfactants decreased the efficiency of the electrolysis of MV²⁺ due to a complex formation between MV²⁺ and the additives and, at a certain [additive]/[MV²⁺] ratio, the complex was adsorbed on the electrode. CV measurements using the USVE showed that ultrasonic irradiation increased the efficiency of the electrolysis greatly but was not able to avoid the adsorption of the complex on the electrode. Optical reflection measurements around the USVE indicated that the ultrasonic irradiation caused little change in the concentration of free MV²⁺ around the electrode. The results showed that the ultrasonic irradiation increased the efficiency of the electrolysis by promotion of mass transport around the electrode, while it was doubted that the irradiation increased the efficiency through decomposition of the complexes.