Electrochemical preparation and characterization of hybrid films composed of Prussian blue type metal hexacyanoferrate and conducting polymer

We propose novel composite (hybrid) organic/inorganic systems that can be f abricated as thin and moderately thick (pin level) films on electrode surfa ces. During electrodeposition by potential cycling alternate layers of poly anilne and metal hexacyanoferrate are produced. Polyaniline can serve as a robust, conductive, matrix for such polynuclear mixed-valence inorganic red ox centers as nickel(II)hexacyanoferrate(III,II). Due to the existence of e lectrostatic attraction between the negatively charged metal hexacyanoferra te and the positively charge polyaniline (partially oxidized), the composit e material cannot be considered as a simple mixture of nickel hexacyanoferr ate and the conducting polymer. It comes from atomic force microscopic stud ies that the morphology of the composite film is granular, but its structur e is fairly dense. The fact, that the formal potential of nickel hexacyanof errate redox process lies in the potential range where polyaniline is condu ctive, allows the system to operate reversibly and reproducibly in acid ele ctrolytes containing potassium cations. The whole concept may lead to the f abrication of composite (hybrid) films that are capable of effective accumu lation of charge and show high current densities at electrochemical interfa ces. (C) 2001 Elsevier Science Ltd. All rights reserved.