Gas flow rate and synthesis time dependence of MWCNT growth by chemical vapour deposition

In this paper we extend our study on the effect of gas flow rate and synthesis time on horizontal multi-wall carbon nanotube (MWCNT) growth and morphology synthesized from methane by double-heater thermal catalytic vapor deposition method (TCVD) using a mixture of methanol and ammonia as active agents to promote the growth of nanotubes. Nickel was used as a catalyst. The prepared nanotubes were characterized by scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM) and energy-dispersive X-Ray spectroscopy (EDS). Results from SEM indicate that the diameter and density of the tubes increased with increasing gas flow rate, whereas the effect of synthesis time was on the CNT length and density. The most favorable gas flow rate was around 100 bubbles per min, in which CNTs formed were uniform, long and dense.