Ferricenium surface-confined

Rate of Reduction of Photogenerated, Surface-Confined Ferricenium by Solution Reductants... 

Scheme I Interface energetics for an n-type Si photoanode at the flat-band condition showing the formal potential for a surface-confined ferricenium/ferrocene reagent relative to the position of the top of the valence band, E ,and the bottom of the conduction band,E , at the interface between the Si substrate and the redox/electrolyte system. Interface energetics apply to an EtOH/0.1 M [n-Bu N]C10 electrolyte system.

Table I. Reduction of Surface-Confined Ferricenium by Iodide in Various Solvents at 298 K.

Photogenerated, surface-confined ferricenium can be reduced by a number of reductants including I-, Co(bipy)2 +s ferrocene, l,l -dimethylferrocene, phenylferrocene. Fe(rr indenyl)2> [Fe(CO)(n5-C5H5)]4, Ru(NH3)62+, Fe(CN)64 and dimethyldithiocarbamate. With the exception of I-, all generally reduce the surface-confined ferricenium with an observed heterogeneous rate constant of >0.06 cm/s which corresponds to a bimolecular rate constant > 6 x 10 M-1s-1, assuming that a monolayer ( 10-10 mol/cm2) of the surface-ferricenium participates in the... 

N. S. Lew is, A. B. Bocarsly, and M. S. Wrighton, Heterogeneous electron transfer at designed semi-conductor/liquid interfaces. Rate of reduction of surface-confined ferricenium centers by solution... 

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