Effects of Synthesis Reaction Temperature, Deposition Time and Catalyst on Yield of Carbon Nanotubes

Abstract

Fluidized bed chemical vapour deposition (FBCVD) has been introduced promising method for carbon nanotubes (CNTs) synthesis because of its large scale, low cost and high yield production. However, there is no clear relation between synthesis parameters and carbon nanotubes growth. Therefore, more data investigations are required for FBCVD synthesis of carbon nanotubes. This research intend to investigate the effects of some synthesis parameters namely reaction temperature, catalyst loading and deposition time on FBCVD growth of carbon nanotubes. In present study, carbon nanotubes were synthesized through decomposition of acetone over a prepared catalyst, iron and molybdenum supported on alumina. After each run the product was characterized using scanning electron microscopy, transmission electron microscopy, thermo gravimetric analysis and energy dispersive X-ray spectroscopy. Besides that the effects of parameters on carbon deposition yield were statistically studied using analysis of variance (ANOVA). The results demonstrated that the ideal reaction temperature was about 750 ºC, by increasing to 950 ºC more amorphous carbon was observed due to deactivation of catalyst at high temperature. It was also observed that by increasing the deposition time, the yield of carbon nanotubes had decreased and by increasing the catalyst loading the yield and quality of carbon nanotubes had increased.