Direct Mechanochemical Formation of Metal Nanoparticles on Carbon Nanotubes

Silver nanoparticles of small average diameter (<5 nm) and rather narrow size distribution rapidly formed on the surfaces of carbon nanotubes in a simple mechanochemical process in which silver acetate was ball-milled with the nanotubes for only a few minutes. The outcome was achieved in the absence of any solvent, any additional reducing agents, or applied electrical current. This simple method was found to be readily applicable to not only carbon nanotubes of various diameters, but also other carbon and noncarbon substrates that are thermally conductive. Different organic metal salts (e.g., gold and palladium acetates and platinum acetylacetonate) were also successfully applied in similar procedures to obtain the corresponding metal−nanotube nanohybrids. The reported mechanochemical process for the preparation of metal nanoparticle-decorated carbon nanotubes is rapid, versatile, and potentially scalable, making it useful for further exploitation in a variety of applications.