In recent research, scientists found that an individual atom of
team of researchers involving scientists from The University of
Nottingham has shown for the first time that chemical reactions at the
nano-level which change the structure of carbon nanotubes can be sparked
by an ‘attack’ from within.
discovery challenges previous scientific thinking that the internal
surface of the hollow nanostructures is chemically unreactive, largely
restricting their use to that of an inert container or a ‘nano-reactor’
inside which other chemical reactions can take place.
Their research, published in the journal Nature Chemistry,
shows that carbon nanotubes that have had their structures changed are
exciting new materials that could be useful in the development of new
technologies for gas storage devices, chemical sensors and parts of
electronic devices such as transistors.
has universally been accepted for some time now that the internal
surface of carbon nanotubes—or the concave side—is chemically
unreactive, and indeed we have been successfully using carbon nanotubes
as nano-reactors, “ says Dr. Andrei Khlobystov, of the University’s
School of Chemistry, who led the work at Nottingham.
in the course of this new research we made the serendipitous discovery
that in the presence of catalytically active transition metals inside
the nanotube cavity, the nanotube itself can be involved in unexpected
nanotubes are remarkable nanostructures with a typical diameter of 1–2
nm, which is 80,000 times smaller than the thickness of a human hair. Dr
Khlobystov and his research associates were recently involved in the
discovery—published in Nature Materials—that
nanotubes can be used as a catalyst for the production of nanoribbon,
atomically thin strips of carbon created from carbon and sulphur atoms.
These nanoribbons could potentially be used as new materials for the
next generation of computers and data storage devices that are faster,
smaller and more powerful.
this latest research, the scientists found that an individual atom of
rhenium metal (Re) sets off a chemical reaction leading to the
transformation of the inner wall of the nanotube. Initially, the attack
by the rhenium creates a small defect in the nanotube wall which then
gradually develops into a nano-sized protrusion by ‘eating’ additional
protrusion then rapidly increases in size and seals itself off, forming
a unique carbon structure dubbed a NanoBud, so called because the
protrusion on the carbon nanotube resembles a bud on a stem.
NanoBuds were believed to be formed outside the nanotube through
reactions on the outer surface with carbon molecules called fullerenes.
new study demonstrates for the first time that they can be formed from
within, provided that a transition metal atom with suitable catalytic
activity is present within the nanotube.
collaboration with the Electron Microscopy of Materials Science group
at Ulm University in Germany, the scientists have even been able to
capture ‘on camera’ the chemical reaction of the transition metal atom
with the nanotube in real time at the atomic level using the latest
aberration-corrected transmission electron microscopy. Their videos show
nanotubes with a diameter of around 1.5 nm, while the NanoBuds are just
1 nm across.