Effect of adding nickel to iron–alumina catalysts on the morphology of as-grown carbon nanotubes

✍ Scribed by Weizhong Qian; Tang Liu; Zhanwen Wang; Hao Yu; Zhifei Li; Fei Wei; Guohua Luo

• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 575 KB
• Volume: 41
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/s0008-6223(03)00324-5

✦ Synopsis

The synthesis of carbon nanotubes (CNTs) from ethylene decomposition by Fe /Al O and Fe / Ni /Al O catalysts 2 3 2 3 (Fe:Ni510:1) is studied. A small amount of nickel introduced into the catalyst can significantly increase the yield of CNTs, but the nanotubes change from straight tubes with concentric parallel carbon sheets to helical tubes of the fish-bone type. Raman characterization of CNTs prepared at 823 and 1023 K and CNTs annealed at 2473 K shows that CNTs deposited on the Fe / Ni /Al O catalyst have poor crystallinity, as compared with that on the Fe /Al O catalyst. These differences are 2 3 2 3

explained by a mechanism of formation of helical tubes of the fish bone type that takes into consideration the differences in the chemical nature of the catalyst with and without nickel.