Electrochemical Method of Preparing Metallic, Polymeric and Organic-Inorganic Hybrid Nanowires inside Porous Anodic Alumina Templates

Abstract

The fabrication of free standing silver, polypyrrole (PPy) and hybrid PPy–Ag nanowire arrays was reported. Silver, PPy and PPy–Ag nanowires were produced by electrochemical deposition/polymerization of metal/polymer in anodic aluminum oxide (AAO) templates. The home–made AAO templates were fabricated by two–step anodization of aluminum performed in oxalic acid, sulfuric acid and phosphoric acid at the anodizing potentials of 25 V, 45 V and 195 V, respectively. Silver nanowires with a diameter of ~40, 80 and 300 nm were synthesized by DC electrode position from a commercially available plating bath. PPy nanowires, ~80 nm in diameter, were synthesized by electropolymerization of a monomer in a solution containing pyrrole (Py) and NaClO4 by applying a constant potential. The hybrid PPy–Ag nanowires, ~80 nm in diameter, were synthesized by a simple simultaneous cathodic electropolymerization of pyrrole and metal deposition in a solution containing HNO₃, NaNO₃, pyrrole (Py) and AgNO₃ by applying a constant potential. After the electrochemical deposition, free standing Ag, PPy and PPy–Ag nanowire arrays were obtained by a subsequent chemical etching of the AAO template in an aqueous NaOH solution. The morphology and structural characterization of fabricated nanowires were performed by FE–SEM and EDAX analyses.

Keywords: AAO templates; Electrodeposition; Electropolymerization; Nanowires.