Bowen Yu, Qiankun Zhang, Lizhen Hou
2016
Citations
0
Influential Citations
32
Citations
Journal
Carbon
Abstract
Abstract Nickel is one of the most commonly used catalysts for the growth of carbon nanofibers (CNFs) by catalytic chemical vapor deposition (CVD). Nevertheless, the chemical state of nickel catalyst, which may be metallic nickel (Ni), nickel subcarbide (Ni 3 C 1-x ) and nickel carbide (Ni 3 C) during the growth process of CNFs, remains a longstanding issue. We report here the catalytic growth of CNFs by CVD at temperatures ranged from 300 to 600 °C. It is demonstrated that the nickel catalyst has different chemical states during the catalytic growth, including Ni 3 C at 300 °C, composite Ni–Ni 3 C 1-x from 400 to 500 °C and metallic Ni at 600 °C, which is clearly dependent on the growth temperature. Our findings reconcile the longstanding debate on the contradictory models (i.e. Ni-assisted growth, Ni 3 C 1-x -assisted growth and Ni 3 C-assisted growth) for the catalytic growth CNFs.