Individuals, grasses, and forests of single- and multi-walled carbon nanotubes grown by supported Co catalysts of different nominal thicknesses

Kazunori Kakehi, Suguru Noda, Shigeo Maruyama, Yukio Yamaguchi

Research output: Contribution to journalArticle

20 Citations (Scopus)


The relationships among the nominal thickness of Co catalyst, the structure of the catalyst particles, and the structure of carbon nanotubes (CNTs) growing from the catalyst during chemical vapor deposition were investigated. Various morphologies of CNTs such as individuals, random networks parallel to the surface of the substrate ('grasses'), and vertically aligned forests of single- and multi-walled carbon nanotubes were grown by only varying the nominal thickness of catalyst under the same reaction condition. These different morphologies at the same growth time were due to the different areal density rather than to the length of CNTs. With increasing nominal thickness of catalyst, the catalyst particles changed in diameter while their areal density remained relatively almost constant. The change in diameter possibly affected the number ratio of active catalyst particles to the whole particles, which in turn affected the areal density of CNTs and yielded the various morphologies. Longer growth time increased the CNT length, which caused further change in CNT morphologies from individuals to grasses and grasses to forests.

Original languageEnglish
Pages (from-to)6710-6714
Number of pages5
JournalApplied Surface Science
Issue number21
Publication statusPublished - 2008 Aug 30
Externally publishedYes



  • Catalyst
  • Chemical vapor deposition
  • Combinatorial method
  • Morphology
  • Multi-walled carbon nanotubes
  • Single-walled carbon nanotubes

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films
  • Condensed Matter Physics

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