Stabilization of n ‐ CdSe Photoanodes in Nonaqueous Fe ( CN ) 6 3 − / 4 − Electrolytes

The systematic development of a nonaqueous ferro‐ferricyanide electrolyte for stabilization of photoanodes is described. Selection of the solvent is discussed in terms of inherent stability provided, the rate of the redox reaction, the tendency toward specific adsorption of the redox species, and the equilibrium potential of the redox couple with respect to the flatband potential (attainable open‐circuit voltage). Results are presented for cells of the type which have been operated for up to 700 hr at 6 mA/cm 2 with no detectable degradation in either the electrode surface or the photoresponse.