Abstract
In this study, the ferrocene weight was increased from 0.1 to 0.2 g to demonstrate the growth of MWCNTs on Si/SiO2/Al2O3 substrate. Ethylene was used as carbon precursor for CNTs nucleation. The as-grown multiwalled carbon nanotubes (MWCNTs) were investigated for the effect of ferrocene weight on yield and crystallinity of nanotubes. TEM, Raman and TGA studies revealed that an increase in ferrocene weight to a certain limit significantly improves the diameter, crystallinity, alignment and % yield of the product. However, above 0.15 g of ferrocene, few nanotubes were having surface defects and some black spots were also evident in TEM images. The lowest inner-shell spacing and ID/IG ratio were evident for 0.15 g ferrocene catalyst which was an indication of relatively pure CNTs growth. Raman spectra also confirmed the highly crystalline and relatively pure CNTs structures with I-D/I-G ratio of 0.851 for 0.15 g ferrocene. TGA data also revealed the formation of pure MWCNTs especially for 0.15 g ferrocene with oxidation temperature of 620 degrees C.