Flame and Furnace Synthesis of Single-Walled and Multi-Walled Carbon Nanotubes and Nanofibers

• Published in: The journal of physical chemistry. B 2001-10, Vol.105 (42), p.10249-10256
• Main Authors: Vander Wal, Randall L, Ticich, Thomas M
• Format: Article
• Language: English
• ISSN: 1520-6106; 1520-5207
• DOI: 10.1021/jp012838u

Results are presented for flame synthesis of metal-catalyzed carbon nanotubes. A thermal evaporation technique is used to create the catalyst nanoparticles of Fe or Ni through gas condensation followed by entrainment into the flame. Results are compared with those using a high-temperature tube furnace to provide the reactive environment. Each system yields consistent results, with CO/H2 mixtures generally yielding single-walled nanotubes (SWNTs) with Fe while C2H2/H2 mixtures usually produce multiwalled nanotubes (MWNTs) with Ni. A ternary gas mixture of CO/C2/H2 produces a better yield of nanofibers than either a CO/H2 or C2H2/H2 mixture at 700 °C with Ni catalyst. Our results reflect a combination or possibly a synergy between thermal- plus adsorbate-induced restructuring and adsorbate−particle steric factors affecting particle structure and reactivity.