Palladized aluminum as a novel substrate for the non-electrolytic preparation of a Prussian Blue film modified electrode

A new type of Prussian Blue (PB) modified electrode is presented on the basis of a simple chemical modification of palladized aluminum surfaces. Electroless deposition of metallic palladium on the aluminum electrode (aluminum palladization) provides a suitable surface for the non-electrolytic deposition of PB, formulated as KFeIII[Fe-II(CN)(6)], films from a solution of ferric ferricyanide. The PB films prepared in such a way are stable, thin, homogeneous and electrochemically active. The electrochemical behavior of the palladized aluminum-based PB modified electrode (PB/Pd-Al) has been investigated. The cyclic voltammetry of the PB/Pd-Al modified electrode exhibits two reversible redox couples resulting from Fe3+/Fe2+ and [Fe(CN)(6)](3-)/[Fe(CN)(6)](4-) transitions in the film. The effect of supporting electrolyte cations, pH and successive potential cycling on the electrochemical behavior and the stability of the modified electrode were investigated. The transfer coefficient (alpha), rate constants of electron transfer (k(s)) and apparent diffusion coefficients of hydrated potassium ion in the film (D-app) for each redox couple were also determined. The PB/Pd-Al modified electrode was used to electrocatalyze the reduction of persulfate ions. (C) 2004 Elsevier B.V. All rights reserved.