Overlayer-Support Interactions Associated with the Formation of a Chemically Modified Interface: The Nickel Ferrocyanide Derivatized Nickel Electrode

The anodization derivatization of nickel ferrocyanide on a nickel electrode is shown to be sensitive (with respect to surface coverage) to the electrode potential and the electrode crystal face. The epitaxial alignment of the Ni(100) face and the nickel ferrocyanide lattice promotes surface derivatization, while the mismatch of the surface layer and the Ni(111) face inhibits formation of a surface overlayer. Electrode potential is found to play a dual role. First, the Ni²⁺ concentration in the interfacial region depends on this parameter; thus both reaction rate and electrode coverage are affected. Second, at higher electrode potentials (>1.0 V vs. SCE), reconstruction of the nickel surface to a surface which promotes epitaxial growth is observed.