A Facile Route for the Self-Organized High-Density Decoration of Pt Nanoparticles on Carbon Nanotubes

Monodisperse Pt nanoparticles (NPs), 3−5 nm in diameter, were synthesized by the formic acid reduction of H 2 PtCl 6 at 80 °C. They were used to decorate single- and multiwalled carbon nanotubes (CNTs), previously sonicated in deionized water, via high surface density self-organization at room temperature. The surface morphologies and chemistries of the decorated NPs were characterized by scanning and transmission electron microscopies and X-ray photoelectron spectroscopy. Zerovalent Pt NPs were found to have uniformly decorated the CNTs at high densities and without aggregation. Their number density (loading) was dependent on both the self-organization time and the CNT concentration for a given aqueous suspension of NPs. The self-organized NP/CNT system demonstrated good electrochemical activity, with promising applications in fuel cells and biosensors.