Growth of thin carbon nanotubes on MoCoMgO catalyst

Thin carbon nanotubes were synthesized by catalytic decomposition of CH4 over MoCoMgO catalyst. We obtained bundles of ordered nanotubes under hydrogen gas and disordered nanotubes under nitrogen gas over the same catalyst. The formation mechanism of nanotube bundles was discussed. The number of the tube walls was 2–5 with the corresponding diameters of 3–6 nm. We obtained a high production yield of 500 wt.% for the thin carbon nanotubes compared to the weight of the supplied catalyst. Moreover the duration of the hydrogen pretreatment was also found to have different effects on the yield of nanotubes under different carrier gases.