Catalytic growth of single- and double-walled carbon nanotubes from Fe-Mo nanoparticles supported on MgO

Single-wall carbon nanotubes (SWNTs) and double-wall carbon nanotubes (DWNTs) are simultaneously synthesized at range of 800-1000 °C by catalytic decomposition of methane over Fe-Mo/MgO catalyst. Carbon nanotubes (CNTs) obtained in this work consisted of SWNTs bundle, isolated SWNT, and isolated DWNTs, having diameter of around 0.8-2.4 nm, 2.4 nm, and 2.4-2.8 nm, respectively. The proportion of DWNTs increases with increasing reaction temperature. The nanotubes synthesized at 800 °C and 900 °C composed of about 95%SWNTs/5%DWNTs and 80%SWNTs/20%DWNTs, respectively. Raman analysis indicates that the quality of CNTs decreased with increasing reaction temperature.