Synthesis of carbon nanostructures by arc evaporation of graphite rods with Co–Ni and YNi2 catalysts Original Research Article

Yields of single-walled carbon nanotubes (SWNTs) produced from electric arc evaporation of graphite electrodes with 3Co/Ni and YNi2 catalysts differ substantially. For instance, with YNi2 catalyst, the SWNT yield is ∼30–50 wt.% in ‘collar’ soot and ∼10–15 wt.% in ‘wall’ soot, while with 3Co/Ni catalyst, the yields are ∼15–20 wt.% and 2–3 wt.%, respectively. According to Raman spectroscopy data, the average dimension of SWNTs is ∼1.2 nm for 3Co/Ni and ∼1.4 nm for YNi2 catalyst. Optimum conditions for synthesis also differ for catalysts compared; namely, for 3Co/Ni: current intensity is 93 A, helium pressure is 650 Torr, the electrode gap is 2.5–3 mm; for YNi2: current intensity is 98 A, helium pressure is 500 Torr, the electrode gap is 1–2 mm.