PtPd nanowire arrays supported on reduced graphene oxide as advanced electrocatalysts for methanol oxidation

摘要

Novel reduced graphene oxide (RGO) nanosheet/PtPd nanowire hybrids were prepared by a mild wet chemical approach. Uniform Pt nanowire arrays are successfully supported on functionalized RGO nanosheets with Pd nanoparticles as growing seeds. The whole deposition process was achieved in aqueous solution at room temperature. TEM and HR-TEM analysis indicated the single-crystal feature of the Pt nanowires with a diameter of ca. 4 nm in average and a length of 20-200 nm. Electrochemical characterization demonstrated that the hybrid nanostructures have a higher catalytic activity and stability than commercial state-of-the-art platinum black catalysts (HispeclOOO) toward the methanol oxidation reaction (MOR). An initial mass activity of 0.51 A mg~(-1) and a degradation ratio of 17.2% after 1000 potential sweeping cycles were achieved for the hybrid nanostructures, compared with 0.44 A mg~(-1) and 27.5% for Pt black, respectively, demonstrating a great potential of this RGO/PtPd hybrids for DMFC applications.