Electrochemical reactivity of ultra-thin cyanometallate films on electrode surfaces

Anodization of metal or semiconducting electrodes in the presence of a cyanometallate complex such as ferricyanide leads to the formation of a mixed metal, cyanide bridge, surface complex. Such species form polycrystalline, three-dimensional networks containing channels into which small cations can be intercalated. The thickness of the surface overlayer can be varied from submonolayer to several hundred layers. The surface confined cyanometallate complexes are found to be electroactive in many cases. Both the thermodynamics and dynamics of these species are found to be a strong function of the morphology and crystal geometry of the surface-confined species.