Longitudinal unzipping of carbon nanotubes to form graphene nanoribbons

Graphene nanoribbons (GNRs), elongated strips of graphite an atom thick, are tipped for a starring role in future electronic devices. Graphene is a conductor, but GNRs express different electronic properties depending on their width. This tunability may make them more attractive than carbon nanotubes in some applications. The production of GNRs in bulk is the next challenge. Here, a team from Rice University reports the production of 100-nm-wide nanoribbons from multi-walled carbon nanotubes by 'unzipping' them with permanganate in acid. The resulting graphene oxide is then reduced to restore electronic conductivity. The process can also make thinner GNRs by unzipping single-walled nanotubes, though more work is needed on ways of disentangling the ribbons produced by this route.