The Open-Circuit Voltage of the Ferrous—thionine Photogalvanic Cell

Our previous analysis of the reaction kinetics in a ferrous—thionine photogalvanic solution is extended to a system with a light and a dark electrode. On the basis of an electro chemical two-electron transfer of the thionine-leucothionine redox couple together with a one-electron transfer of the ferric-ferrous couple, experimental open-circuit voltage versus light intensity curves agree well with calculated values, for Pt or Au as a light-electrode material.