In situ observations of catalyst dynamics during surface-bound carbon nanotube nucleation.
We present atomic-scale, video-rate environmental transmission electron microscopy and in situ time-resolved X-ray photoelectron spectroscopy of surface-bound catalytic chemical vapor deposition of single-walled carbon nanotubes and nanofibers. We observe that transition metal catalyst nanoparticles on SiOx support show crystalline lattice fringe contrast and high deformability before and during nanotube formation. A single-walled carbon nanotube nucleates by lift-off of a carbon cap. Cap stabilization and nanotube growth involve the dynamic reshaping of the catalyst nanocrystal itself. For a carbon nanofiber, the graphene layer stacking is determined by the successive elongation and contraction of the catalyst nanoparticle at its tip.
Hofmann
Stephan
S
Department of Engineering, University of Cambridge, Cambridge CB3 0FA, UK. sh315@cam.ac.uk
Sharma
Renu
R
Ducati
Caterina
C
Du
Gaohui
G
Mattevi
Cecilia
C
Cepek
Cinzia
C
Cantoro
Mirco
M
Pisana
Simone
S
Parvez
Atlus
A
Cervantes-Sodi
Felipe
F
Ferrari
Andrea C
AC
Dunin-Borkowski
Rafal
R
Lizzit
Silvano
S
Petaccia
Luca
L
Goldoni
Andrea
A
Robertson
John
J