Facile synthesis of poly(amidoamine)-modified carbon nanospheres supported Pt nanoparticles for direct methanol fuel cells

In this work, the synthesis and characterization of a catalyst material consisted of Pt, poly(amidoamine) (PAMAM) and carbon nanospheres are investigated. Firstly, carbon nanospheres are hydrothermally synthesized, followed by a high temperature of calcination to achieve a high amount of oxygen-containing groups. Subsequently, these carbon nanospheres are modified with multifunctional PAMAM dendrimers to form coordinate complex with H2PtCl6, followed by the reduction with sodium borohydride to obtain metallic Pt. The resulting composites are characterized by transmission electron microscopy (TEM), Xray photoelectron spectroscopy (XPS) and infrared spectroscopy (IR). This new nanomaterial is used as catalysts for methanol electro-oxidation and their electrochemical features are investigated in detail by cyclic voltammetry, chronoamperometry and CO-stripping analysis. The results of this study suggest that, through modification with multifunctional dendrimers, complex carbon nanospheres-based materials can be fabricated, where Pt nanoparticles are smaller, more abundant and more uniformly distributed, thereby providing higher electrocatalytic ability in direct methanol fuel cell and many possibilities for various applications in biosensors and biomedical diagnosis. (C) 2011 Elsevier B.V. All rights reserved.