Ultra-fast electropolymerization of pyrrole in aqueous media on oxidizablemetals in a one-step process

zA general one-step electrosynthesis process for polypyrrole (Ppy) films ap plicable to a large range of oxidizable metals is described. The process is based on the use of an aqueous medium containing a salicylate salt and pyr role. The salicylate salt is quite specific: it passivates the substrate wi thout preventing electropolymerization of pyrrole and, therefore, makes it possible to obtain strongly adherent PPy films, with controlled thickness, either by cyclic voltammetry or by electrolysis at constant current. In the latter case the process does not involve any induction period correspondin g to a preliminary dissolution of the metal, the current efficiencies are c lose to 100%, and the deposition rate can be very high (1 mu m s(-1), corre sponding to current densities as high as 500 mA cm(-2)). (C) 1999 Elsevier Science S.A. All rights reserved.