Transport and kinetics at microheterogeneous electrodes: Part II. Application to a photogalvanic cell

The transport and kinetics of photogeneted species in a proposed photogalvanic cell [1] using colloidal electrode particles are considered. Solution of the differential equations allows the conditions for an efficient cell for solar energy conversion to be found. Compared to an ordinary photogalvanic cell of the iron thionine type, the rate constant for the back reaction can be up to 10³ larger at 10⁶ dm³ mol⁻¹ s⁻¹. However, there are severe constraints on the electrochemical rate constants; the colloidal electrode particles need to be very selective. In an efficient cell the dye may become bleached. The conditions here are the same as for the ordinary photogalvanic cell and hence the dye must be sufficiently soluble to absorb the solar radiation in 10⁻⁴ cm.