Abstract
Multiwall carbon nanotubes (CNTs) were prepared by catalytic decomposition of acetylene at 550°C with Cr-Ni as catalysts and then the CNTs were treated by ball-milling for 45min. The CNTs were purified by removing most of amorphous carbon using air oxidation from 300°C to 500°C in ambient air. Field emission properties of the CNTs were investigated. The results indicate that morphology and field emission properties of the CNTs are mainly dependent on oxidation temperatures. Field emission current density increases to the maxium value at 400°C and then decreases dramatically with increase of oxidizing temperature. When the oxidizing temperature is 400-450°C, the most of amorphous carbon is removed and purity of the CNTs is improved greatly, and the purified CNTs shows excellent field emission properties, such as high emission current density and low turn-on field. The emission properties are degraded if the oxidizing temperature is high (>450°C) due to the increasing of amorphous phase and graphitization of CNTs.
| Original language | English |
|---|---|
| Pages (from-to) | 16-20 |
| Number of pages | 5 |
| Journal | Cailiao Rechuli Xuebao/Transactions of Materials and Heat Treatment |
| Volume | 29 |
| Issue number | 4 |
| State | Published - Aug 2008 |
Keywords
- Ball milling
- Carbon nanotube
- Field emission
- Oxidation