High-purity and well-graphitized single-walled carbon
nanotubes
(SWCNTs) with excellent physiochemical properties are ideal building
blocks for the assembly of various CNT macrostructures for a wide
range of applications. We report the preparation of high-quality SWCNTs
on a large scale using a floating catalyst chemical vapor deposition
(FCCVD) method. Under the optimum conditions, the conversion rate
of the carbon source to SWCNTs reached 28.8%, and 20.4% of the metal
nanoparticles were active for SWCNT growth, which are 15% and ∼400
times higher than those previously reported for FCCVD synthesis, respectively.
As a result, the prepared SWCNTs have a very low residual catalyst
content of ∼1.9 wt % and a high rapid oxidation temperature
of 717 °C. Using these high-quality SWCNTs, we spun macroscopic
SWCNT fibers by a wet-spinning process. The resulting fibers had a
high electrical conductivity of 6.67 MS/m, which is 32% higher than
the best value previously reported for SWCNT fibers.