Bimetallic Au_core - Ag_shell nanoparticles from interfacial redox process using poly(o-methoxyaniline)

Abstract

Stable Au_core-Ag_shell bimetallic nanoparticles are produced in organic medium through an interfacial redox method using the redox property of an organically soluble conducting polymer poly(o-methoxyaniline) (POMA). The transition of the emeraldine base (EB) form of POMA to its pernigraniline base (PB) form occurs during nanoparticle formation and also the nitrogen atoms of POMA (PB) stabilize the nanoparticles via coordination. TEM images indicate that the interfacial redox replacement reaction between Au (III) in aqueous medium and Ag (0) in organic medium produces bimetallic nanoparticles with Au_core-Ag_shell morphology. The formation of such type of core-shell morphology is due to the different standard reduction potentials of the metal ions. The core-shell thickness of the bimetallic nanoparticle can be regulated by changing the POMA (EB) concentration in the organic layer.