Reduced diameter distribution of single-wall carbon nanotubes by selective oxidation

We report an easy way to narrow the diameter distribution of single-walled carbon nanotubes (SWNT) by oxidization treatments. Both a chemical treatment in 2 M HNO3 as well as oxidation in a reduced O-2 atmosphere lead to a selective burning of the narrower SWNT in bulk samples and to a diameter distribution which is smaller by a factor of two. This is a first important step towards a selective production of SWNT with a defined diameter on a bulk scale. (C) 2002 Elsevier Science B.V. All rights reserved.