Growth of Carbon Nanotubes Using MgO Supported Mo-Co Catalysts by Thermal Chemical Vapor Deposition Technique

2013 ◽  
Vol 24 ◽  
pp. 46-57 ◽  
Author(s):  
C. Santhosh ◽  
M. Saranya ◽  
S. Felix ◽  
R. Ramachandran ◽  
N. Pradeep ◽  
...  

A simple method is developed for the synthesis of carbon nanotubes (CNTs) using Mo-Co/MgO catalyst by a thermal chemical vapor deposition (CVD) technique. Acetylene was used as the source of carbon and nitrogen as carrier gas. A series of MgO supported Mo-Co catalysts were prepared by the combustion route using urea as the fuel at different stoichiometric ratios. It was found that a higher yield of carbon nanotubes was obtained by the developed catalysts. Also, the addition of molybdenum to Co/MgO catalysts could remarkably increase the yield and also improve the quality of CNTs from thermal CVD with acetylene as precursor gas. The morphology of the catalysts and CNTs obtained was studied by field emission scanning electron microscope (FE-SEM). Other techniques like Raman spectroscopy and XRD were also employed to know the physico-chemical properties of the samples.

Author(s):  
Kinghong Kwok ◽  
Wilson K. S. Chiu

An open-air laser-induced chemical vapor deposition technique has been successfully used to rapidly deposit pillars of carbon nanotube forest on a moving glass substrate. A CO2 laser is used to heat a traversing fused quartz rod covered with metal particles inside a hydrocarbon environment. Pyrolysis of hydrocarbon precursor gas occurs and subsequently gives rise to the growth of multi-wall carbon nanotubes on the substrate surface. The experimental results indicate that nanotube growth kinetics and microstructure are strongly dependent on the experimental parameters such as laser power. The typical deposition rate of carbon nanotubes achieved in this study is over 50 μm/s, which is relatively high compared to existing synthesis techniques. At high power laser irradiation, carbon fibers and carbon film are formed as a result of excessive formation of amorphous carbon on the substrate. High-resolution transmission and scanning electron microscopy, and x-ray energy-dispersive spectrometry are used to investigate the deposition rate, microstructure and chemical composition of the catalytic surface and the deposited carbon nanotubes.


Sign in / Sign up

Export Citation Format

Share Document