Highly dispersed Pt nanoparticles immobilised on 3-amino-silane-modified MWNT materials for methanol oxidation

Abstract

We demonstrate the use of molecular monolayers to enhance the nucleation of electrocatalytically active platinum nanocrystals onto carbon nanotubes. The multiwalled carbon nanotube (MWNT) is embedded within the polysiloxane shell with large amounts of hydrophilic amino groups outside after the siloxane is polymerized on the nanotube surfaces. Subsequent deposition of platinum nanoparticles led to high densities of 2- to 5-nm diameter Pt nanocrystals uniformly deposited along the length of the carbon nanotubes. The structure and nature of the resulting Pt/Si–MWNT composites were characterized by transmission electron microscopy and X-ray diffraction. Electrochemical measurements show that the molecular monolayers do not impede redox behavior of the electrode, and measurements of the electrocatalytic oxidation of methanol show very high catalytic efficiency.