The effect of catalyst on synthesis of carbon nanotubes: An in situ TGA study.

Synthesis of CNT is carried out in situ in a thermal gravimetric analyzer (TGA) to closely monitor the growth process. Fe and Fe-Mo are used as catalyst and impregnated in porous MgO that act as catalytic support. By programmed heating catalyst-support with methane as carbon source in a TGA furnace, the CNT growth is achieved. From quantitative estimates we show that CNT growth rate is well sustained by the addition of Mo to the active catalyst. We further elucidate with SEM images and radial breathing modes of Raman spectra that addition of Mo also results in reduction of tube diameter. [ABSTRACT FROM AUTHOR]