Localized fabrication of carbon nanotubes forest at a needle electrode by atmospheric pressure corona discharge

Characteristics of the growth of multi-walled carbon nanotubes (CNTs) at a localized surface of a needle-shaped graphite cathode by corona discharge were investigated with varied temperature, 400–1000 °C. For the CNTs' growth, C2H4 in H2 stream was used as carbon source. The CNTs were observed in aligned form on the tip of a needle-shaped cathode under the present condition. It was observed that the temperature range for the CNTs' growth with corona discharge, 600–800 °C, was lower than that that without corona discharge, 700–1000 °C. In the relevant reaction system, strong electric field at the cathode tip enforced the CNTs to grow straightly to form the free-standing aligned CNT forest at a specifically narrow tip zone of the needle cathode.