Resumen de Chemical Vapor Deposition of Carbon Nanotubes: An Experiment in Materials Chemistry
Though a tremendous amount of research has recently been devoted to synthesis and characterization of carbon nanotubes, few students have been afforded the opportunity to study these species in a laboratory course setting. As a part of an introductory laboratory course in the Chemical and Materials Physics (ChaMP) graduate program at UC Irvine, a module was designed wherein students synthesized carbon nanotubes and performed characterization studies using field emission scanning electron microscopy (FESEM). Methane gas was pyrolyzed at 1000 °C to generate nanotubes on alumina-supported Fe2O3 particles. The iron concentration of the catalyst particles was varied to determine the effect of catalyst composition on nanotube growth. Energy dispersive X-ray spectrometry (EDX) indicated that an iron concentration greater than 1.6 atom % in the catalyst particles was necessary in order to produce nanotubes rather than amorphous carbon deposits. Further, as the iron concentration was increased in the range of 2.40-7.51 atom %, there were concomitant increases in both the yield of nanotubes and average nanotube diameters.
