Pt nanowires prepared via a polymer template method: Its promise toward high Pt-loaded electrocatalysts for methanol oxidation

Platinum nanowires were prepared via a template-synthesis method by electrodeposition of platinum within pores of a track-etched polycarbonate (PCTE) membrane, followed by chemical etching to separate the Pt nanowires from the polymer. The structure and morphology of the Pt nanowires were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM), revealing a polycrystalline phase with nanowire dimension up to 6 mu m long and ca. 47 +/- 9.8 nm of diameter. The unsupported Pt nanowires showed the better electrochemical mass activities over the methanol electro-oxidation than supported or unsupported Pt nanoparticles under the high Pt content-loaded conditions that is typically required for direct methanol fuel cells. This enhancement could be rationalized by its unique physicochemical and electrical properties arising from the inherent anisotropic one-dimensional (1D) nanostructure, such as charge transfer facilitation by reducing number of particle interfaces and more efficient use of Pt by alleviating fraction of embedded catalysts. (C) 2008 Elsevier Ltd. All rights reserved.