Preparation of Pt-Pd/PANI/Graphene Nanosheets Composites as Electrocatalysts for Direct Methanol Fuel Cell

Abstract

The synthesis of noble metal nanoparticle with controlled shapes is an attractive goal in developing highly active catalysts. However, constructing high-quality noble metallic nanocatalysts with good electrocatalytic activity remains a huge challenge to date. In this research work, the high-quality polyaniline functionalized graphene nanosheets (PANI/GNS) were prepared by an interfacial polymerization method. The abundant -NH2 groups onto the surface of resulted PANI/GNS nanocomposites, and can be used as active site for growing high load rate of Pd nanoparticles (NPs). Subsequently, Pt NPs were successfully deposited on the Pd surface formed Pt-Pd/PANI/graphene nanosheets (Pt-Pd/PANI/GNS) composites. Interestingly, the shape of Pt-Pd bimetallic can be effectively controlled by simply changing the reaction parameters. The shape and structure of nanocatalysts were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The electrocatalytic properties of nanocomposites were characterized by cyclic voltammetry (CV). The TEM images show that the Pt-Pd nanoflowers were successfully decorated onto the surface of PANI/GNS nanocomposites. The electrocatalytic properties for dioxygen and methanol of prepared Pt-Pd/PANI/GNS nanocatalyst were investigated. The electrochemical results show that the nanocatalysts exhibit higher electrocatalytic activity for methanol oxidation and dioxygen reduction.