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In situ Observations of Catalyst Dynamics during Surface-Bound Carbon Nanotube Nucleation

2007; American Chemical Society; Volume: 7; Issue: 3 Linguagem: Inglês

10.1021/nl0624824

1530-6992

Stephan Hofmann, Renu Sharma, Caterina Ducati, Gaohui Du, Cecilia Mattevi, Cinzia Cepek, Mirco Cantoro, Simone Pisana, Atlus Parvez, Felipe Cervantes‐Sodi, Andrea C. Ferrari, Rafal E. Dunin‐Borkowski, Silvano Lizzit, L. Petaccia, A. Goldoni, John Robertson,

Fullerene Chemistry and Applications

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.