Abstract
Multi-walled carbon nanotubes (MW-CNTs) were fabricated at a surface of a needle-like graphite cathode by corona discharge in H2-C2H4 mixture at atmospheric pressure. The MW-CNTs were observed in aligned form on the tip of a needle-shaped cathode. To grow these MW-CNTs, corona discharge (0.30 mA) was generated between Ni-coated cathode and rod anode in H2 stream with 1% C2H4 at 600-1000°C. The mean diameter and the length of the MW-CNTs were measured to be 30-80 nm and 1-10 µm, respectively. Compared with the MW-CNTs growth without the corona discharge, these MW-CNTs can grow at a significantly lower temperature range, and the structure of the resulted MW-CNTs was rather straight. It is considered that strong electric field strength at the cathode tip enforces the nanotubes to grow straightly while this electric field induces reactive carbonaceous radicals which are converted to MW-CNTs at the Ni catalysis.
