Modified carbon nanotubes: an effective way to selective attachment of gold nanoparticles

Through various modifications of carbon nanotubes (CNTs), gold nanoparticles were selectively attached to the nanotube and the locations of functional groups were further confirmed. Using cationic polyethyleneamine or anionic citric acid as the dispersant, the surface properties of CNTs could be changed to yield a basic or acidic surface. By electrostatic interaction, the CNTs could be successfully coated with about 10 nm gold nanoparticles. After heat treatment in NH3, about 1-2 nm gold nanocluster-filled nanotubes were achieved. This shows that the beat treatment with NH3 could make CNTs open-ended and generate functional basic groups on the inner wall of the nanotubes. (C) 2003 Elsevier Ltd. All rights reserved.