Hollow nanotubes of SiO 2 , Al 2 O 3 , V 2 O 5 , and MoO 3 have been prepared using carbon nanotubes as templates. The procedure involves coating the carbon nanotubes with tetraethylorthosilicate, aluminum isopropoxide, or vanadium pentoxide gel, followed by calcination and heating at higher temperatures in air to oxidize the carbon. SiO 2 nanotubes containing transition metal ions have been prepared by this procedure since such materials may be of use in catalysis.

Acid-treated carbon nanotubes have been decorated with nanoscale Au, Pt and Ag clusters by employing several procedures. The nature and extent of metal coverage can be varied by changing the concentration of the metal compound or by mild sonication (treatment with ultrasound). The metal clusters seem to get deposited on the acidic surface sites of the nanotubes.

No abstract