High-yield catalytic synthesis of thin multiwalled carbon nanotubes and their field emission characteristics

We have synthesized thin multi-walled carbon nanotubes (thin MWCNTs) using a catalytic chemical vapor deposition (CCVD) method with FeMoMgO catalyst. The number of nanotube walls were 2 ∼ 6 with the corresponding diameters of 3 ∼ 6 nm. We obtained a high production yield of over 3000 wt% compared to the weight of the supplied catalyst. These thin MWCNTs revealed the intermediate structural characteristics between single- and multi-walled carbon nanotubes (SWCNTs and MWCNTs). Critical issues for mass production of thin MWCNTs were further discussed in terms of reduction procedure, growth time, and gas species. We have demonstrated that the thin MWCNTs reveal better field emission characteristics particularly in long-term stability as compared to the counterpart SWCNTs and MWCNTs.