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Title: Nanocatalyst shape and composition during nucleation of single-walled carbon nanotubes

The dynamic evolution of nanocatalyst particle shape and carbon composition during the initial stages of single-walled carbon nanotube growth by chemical vapor deposition synthesis is investigated. Classical reactive and ab initio molecular dynamics simulations are used, along with environmental transmission electron microscope video imaging analyses. A clear migration of carbon is detected from the nanocatalyst/substrate interface, leading to a carbon gradient showing enrichment of the nanocatalyst layers in the immediate vicinity of the contact layer. However, as the metal nanocatalyst particle becomes saturated with carbon, a dynamic equilibrium is established, with carbon precipitating on the surface and nucleating a carbon cap that is the precursor of nanotube growth. A carbon composition profile decreasing towards the nanoparticle top is clearly revealed by the computational and experimental results that show a negligible amount of carbon in the nanoparticle region in contact with the nucleating cap. The carbon composition profile inside the nanoparticle is accompanied by a well-defined shape evolution of the nanocatalyst driven by the various opposing forces acting upon it both from the substrate and from the nascent carbon nanostructure. In conclusion, this new understanding suggests that tuning the nanoparticle/substrate interaction would provide unique ways of controlling the nanotube synthesis.
Authors:
 [1] ;  [1] ;  [2] ;  [3] ;  [1]
  1. Texas A & M Univ., College Station, TX (United States)
  2. National Institute of Standards and Technology, Gaithersburg, MD (United States); Univ. of Maryland, College Park, MD (United States)
  3. Univ. of Maryland, College Park, MD (United States)
Publication Date:
Grant/Contract Number:
FG02-06ER15836
Type:
Accepted Manuscript
Journal Name:
RSC Advances
Additional Journal Information:
Journal Volume: 5; Journal Issue: 129; Journal ID: ISSN 2046-2069
Publisher:
Royal Society of Chemistry
Research Org:
Texas A&M Univ., College Station, TX (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
OSTI Identifier:
1342511

Gomez-Ballesteros, Jose L., Burgos, Juan C., Lin, Pin Ann, Sharma, Renu, and Balbuena, Perla B.. Nanocatalyst shape and composition during nucleation of single-walled carbon nanotubes. United States: N. p., Web. doi:10.1039/C5RA21877B.
Gomez-Ballesteros, Jose L., Burgos, Juan C., Lin, Pin Ann, Sharma, Renu, & Balbuena, Perla B.. Nanocatalyst shape and composition during nucleation of single-walled carbon nanotubes. United States. doi:10.1039/C5RA21877B.
Gomez-Ballesteros, Jose L., Burgos, Juan C., Lin, Pin Ann, Sharma, Renu, and Balbuena, Perla B.. 2015. "Nanocatalyst shape and composition during nucleation of single-walled carbon nanotubes". United States. doi:10.1039/C5RA21877B. https://www.osti.gov/servlets/purl/1342511.
@article{osti_1342511,
title = {Nanocatalyst shape and composition during nucleation of single-walled carbon nanotubes},
author = {Gomez-Ballesteros, Jose L. and Burgos, Juan C. and Lin, Pin Ann and Sharma, Renu and Balbuena, Perla B.},
abstractNote = {The dynamic evolution of nanocatalyst particle shape and carbon composition during the initial stages of single-walled carbon nanotube growth by chemical vapor deposition synthesis is investigated. Classical reactive and ab initio molecular dynamics simulations are used, along with environmental transmission electron microscope video imaging analyses. A clear migration of carbon is detected from the nanocatalyst/substrate interface, leading to a carbon gradient showing enrichment of the nanocatalyst layers in the immediate vicinity of the contact layer. However, as the metal nanocatalyst particle becomes saturated with carbon, a dynamic equilibrium is established, with carbon precipitating on the surface and nucleating a carbon cap that is the precursor of nanotube growth. A carbon composition profile decreasing towards the nanoparticle top is clearly revealed by the computational and experimental results that show a negligible amount of carbon in the nanoparticle region in contact with the nucleating cap. The carbon composition profile inside the nanoparticle is accompanied by a well-defined shape evolution of the nanocatalyst driven by the various opposing forces acting upon it both from the substrate and from the nascent carbon nanostructure. In conclusion, this new understanding suggests that tuning the nanoparticle/substrate interaction would provide unique ways of controlling the nanotube synthesis.},
doi = {10.1039/C5RA21877B},
journal = {RSC Advances},
number = 129,
volume = 5,
place = {United States},
year = {2015},
month = {12}
}