AN INVESTIGATION ON THE ADSORPTION CHARACTERISTICS AND ORIENTATIONS MODEL OF PYRROLE ON SMOOTH PLATINUM-ELECTRODE

Since the electropolymerization mechanism is believed to involve the i nitial adsorption of the monomer on to the electrode surface, in this paper, different criteria for the electroadsorption of pyrrole on a sm ooth polycrytalline platinum electrode were investigated in different pH media. Experiments were performed in a neutral medium (0.1 M Na2HPO 4 + 0.1 M KH2PO4) and an H2SO4 aqueous medium as functions of pyrrole concentration, adsorption time and adsorption potential. The adsorptio n kinetics and isotherms were studied at constant potential. The numbe r of electrons per occupied site (n(e)) and surface coverage ratios (t heta) were calculated. Possible orientation models were proposed for a dsorbed species. Copyright (C) 1996 Elsevier Science Ltd