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.