Graphitic encapsulation of catalyst particles in carbon nanotube production
Artikel i vetenskaplig tidskrift, 2006

A new model is proposed for the encapsulation of catalyst metal particles by graphite layers that are obtained, for example, in low-temperature chemical vapor deposition production of carbon nanotubes (CNTs). In this model graphite layers are primarily formed from the dissolved carbon atoms in the metal-carbide particle when the particle cools. This mechanism is in good agreement with molecular dynamics simulations (which show that precipitated carbon atoms preferentially form graphite sheets instead of CNTs at low temperatures) and experimental results (e.g., encapsulated metal particles are found in low-temperature zones and CNTs in high-temperature regions of production apparatus, very small catalyst particles are generally not encapsulated, and the ratio of the number of graphitic layers to the diameter of the catalyst particle is typically 0.25 nm(-1)).

MAGNETIC-PROPERTIES

SWNT GROWTH

NANOPARTICLES

NI

SINGLE-WALLED NANOTUBES

SIZE

MOLECULAR-DYNAMICS

METAL PARTICLES

GAS-PHASE

NANOCAPSULES

Författare

Feng Ding

Göteborgs universitet

Arne Rosen

Göteborgs universitet

Eleanor E B Campbell

Göteborgs universitet

Lena Falk

Chalmers, Teknisk fysik

Kim Bolton

Göteborgs universitet

Journal of Physical Chemistry B

1520-6106 (ISSN) 1520-5207 (eISSN)

Vol. 110 15 7666-7670

Ämneskategorier

Fysikalisk kemi

Annan materialteknik

Kemi

DOI

10.1021/jp055485y