Flame synthesis enables the mass-production of carbon black and fullerene but not of carbon nanotubes (CNTs) due to the narrow window for producing CNTs while preventing tar generation. We report a flame-assisted chemical vapor deposition method, in which a premixed flame is used for the instantaneous generation of floating catalysts, the heating of the gas, and the growth of single-wall CNTs (SWCNTs) using a furnace at the downstream of the flame. This method yields high quality SWCNTs with a small average diameter of 0.96 nm, a small diameter deviation of 0.21 nm, and a high carbon purity of ∼90 wt%. Multiple parameters affect the SWCNT production significantly, which are investigated systematically and optimized carefully. The effects and possible mechanisms of the key parameters are discussed.
Okada, S., Sugime, H., Hasegawa, K., Osawa, T., Kataoka, S., Sugiura, H., & Noda, S. (2018). Flame-assisted chemical vapor deposition for continuous gas-phase synthesis of 1-nm-diameter single-wall carbon nanotubes. Carbon, 138, 1–7. https://doi.org/10.1016/j.carbon.2018.05.060