Synthesis of Conducting Polymer Supported Pd Nanoparticles in Aqueous Medium and Catalytic Activity Towards 4-Nitrophenol Reduction

We report here the synthesis of palladium (Pd) nanoparticles incorporated poly-(3,4)ethylenedioxythiophene (PEDOT) matrix in aqueous medium and its catalytic performance towards 4-nitrophenol reduction. This simple one-pot synthesis involving a redox reaction between 3,4-ethylenedioxythiophene and palladium chloride (PdCl2) precursor, leads to the formation of Pd nanoparticles supported on particulate PEDOT. Pd nanoparticles of size 1-9 nm were found to distribute uniformly over the PEDOT matrix. Morphology of the Pd-PEDOT nanocomposite was characterized by field emission-scanning electron microscopy and transmission electron microscopy and the crystallographic details obtained using X-ray diffraction. The chemical nature of the PEDOT support matrix was analyzed using Fourier transform-infra red (FT-IR) spectroscopy. The catalytic activity of the composite was demonstrated using a model reaction, i.e., reduction of 4-nitrophenol to 4-aminophenol. The value of the apparent rate constant, ca. 65.8 x 10(-3) s(-1) obtained using UV visible spectroscopy of the reduction of 4-nitrophenol at the Pd-PEDOT nanocomposite is comparable to those reported for other catalytic systems.