PARAMETRIC STUDY ON THE GROWTH OF SINGLE-WALLED CARBON NANOTUBES OVER CO-MO/MGO NANOCATALYST IN A FLUIDIZED BED REACTOR BY CCVD METHOD

Single-walled carbon nanotubes (SWNTs) with high yield and quality were synthesized using chemical vapor deposition (CVD) over Co-Mo/ MgO nanocatalyst in a fluidized bed reactor. Different parameters such as temperature, the ratio of hydrocarbon source to hydrogen, the flow rate of gas, growth time, the size of catalyst particles, heating rate, and the kind of hydrocarbon source were examined to assess their effects on the SWNT synthesis. The influence of these parameters on the carbon nanotubes yield and quality is also reported. Single-walled carbon nanotubes were characterized by using different characterization techniques including thermogravimetric analysis (TGA), scanning electron microscopy (SEM), tunneling electron microscopy (TEM), Raman spectroscopy, and X-ray diffraction (XRD). Under the optimum operation conditions (900 °C, 30 min, rate of gas=1800 ml/min, heating rate of 7 °C/min, size of catalyst particle=212 ?m, volumetric ratio of hydrocarbon source to hydrogen=1:1), single-walled carbon nanotubes with an average diameter of 0.9 nm and a yield of 300% (related to the catalyst) were produced.