Simultaneous Formation of Separate Conducting and Insulating Layers on Aluminum Electrode by Electrolysis

摘要

Two films, conducting (polypyrrole; PPy) and insulating (Al_2O_3), were successfully formed as separate layers on an Al electrode by a simple electrochemical oxidation of aluminum metal in aqueous solution which contains pyrrole monomer and an anionic surfactant electrolyte, namely, n-dodecylbenzenesulfonate. Using a surfactant electrolyte, three layers of thin films (PPy/Al_2O_3/Al) can be simultaneously formed simply by electrolyzing Al metal. The formation of PPy/Al_2O_3 layers on Al electrodes has been confirmed by direct observation (using scanning electron microscopy) and characterized electrochemically. AC impedance spectroscopic analysis demonstrated an excellent impedance-frequency characteristic for a sample electrolytic capacitor formed from a PPy/Al_2O_3/Al film.