One-pot synthesis of polypyrrole film on an aluminum oxide layer by electropolymerization in the presence of ammonium borodisalicylate in acetonitrile

Abstract

Abstract This paper describes how one-pot preparation of polypyrrole (PPy) on Al 2 O 3 layer in an aluminum solid capacitor could be achieved by electropolymerization of pyrrole (Py) in acetonitrile with small amounts of water, using ammonium borodisalicylate (ABS) as a new electrolyte. The effects of monomer and electrolyte concentrations, current density, and polymerization temperature on the PPy formation on Al 2 O 3 layer in aluminum solid are also discussed. Polymerization occurred smoothly to give PPy on the Al 2 O 3 layer under the following conditions: [ammonium borodisalicylate] = 0.02 M, [Py] = 0.1 M, and polymerization temperature = −42 °C, current density = 10 mA cm −2 . The normalized capacitance, the C p / C 0 value of capacitor fabricated, reached more than 0.9, indicating that the porosity and surface of the Al 2 O 3 layer are filled up and covered with PPy. The Raman spectra of the PPy film showed that the peak assignable to C C backbone stretching shifted to a lower wave number of 1585 cm −1 . This indicates formation of the film with well-conjugated C C backbone. The SEM micrograph of PPy on Al 2 O 3 layer showed a closely packed globular morphology. These results indicate that the new electrolyte, ABS, has an excellent ability to form PPy film directly on Al 2 O 3 surface by electropolymerization.