Structure and morphology of carbon nanotubes grown on zeolite-supported catalysts by chemical vapor deposition

The zeolite-supported catalysts were prepared in nickel and cobalt nitrate aqueous solutions by ion exchange method. After reducing these substrates b y hydrogen, we grew carbon nanotubes on them by chemical vapor deposition u nder different conditions. The results reveal that nickel/zeolite, cobalt/z eolite and nickel+cobalt/zeolite have different optimal conditions. When ni ckel+cobalt/zeolite was used as the catalyst, we can get straight carbon na notubes. The Raman spectrum of the straight nanotubes shows they have fewer defects. We propose a growth mechanism for the growth of these nanotubes.