Electrode kinetics of photoinduced redox reactions: phenazine dye-EDTA aqueous systems at different pH

Abstract

The photogalvanic effect in phenazine dye-EDTA aqueous systems was studied at different pH. The photovoltage growth and decay curves follow the functional forms related to the relaxation times. Under the experimental conditions, the inverse of the relaxation time or the rate of electrode reaction is pH dependent. The rate constants k of forward and backward reactions at 25 °C were calculated. From the plot of log k vs. pH catalytic constants for H+ and OH− were determined. The thermodynamic properties and the possible mechanism of the cells are discussed.