Growth window and possible mechanism of millimeter-thick single-walled carbon nanotube forests

Kei Hasegawa, Suguru Noda, Hisashi Sugime, Kazunori Kakehi, Shigeo Maruyama, Yukio Yamaguchi

Research output: Contribution to journalArticle

32 Citations (Scopus)


Our group recently reproduced the water-assisted growth method, so-called "SuperGrowth," of millimeter-thick single-walled carbon nanotube (SWNT) forests by using C 2H 4/H 2/H 2O/Ar reactant gas and Fe/Al 2O 3 catalyst. In this current work, a parametric study was carried out on both reaction and catalyst conditions. Results revealed that a thin Fe catalyst layer (about 0.5 nm) yielded rapid growth of SWNTs only when supported on Al 2O 3, and that Al 2O 3 support enhanced the activity of Fe, Co, and Ni catalysts. The growth window for the rapid SWNT growth was narrow, however. Optimum amount of added H 2O increased the SWNT growth rate but further addition of H 2O degraded both the SWNT growth rate and quality. Addition of H 2 was also essential for rapid SWNT growth, but again, further addition decreased both the SWNT growth rate and quality. Because Al 2O 3 catalyzes hydrocarbon reforming, Al 2O 3 support possibly enhances the SWNT growth rate by supplying the carbon source to the catalyst nanoparticles. The origin of the narrow window for rapid SWNT growth is also discussed.

Original languageEnglish
Pages (from-to)6123-6128
Number of pages6
JournalJournal of Nanoscience and Nanotechnology
Issue number11
Publication statusPublished - 2008 Nov 1



  • Combinatorial method
  • Growth mechanism
  • Growth window
  • Single-walled carbon nanotubes
  • Vertically aligned nanotubes

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Biomedical Engineering
  • Materials Science(all)
  • Condensed Matter Physics

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