Fabrication of carbon nanofibres and bambooshaped carbon nanotubes with open ends from anthracite coal by arc discharge

Bamboolike carbon nanotube (BCNTs) with open ends, and carbon nanofibers (CNFs) were prepared from a coalbased carbon rod by a DC arc discharge. The coalbased carbon rod was made by carbonizing Chinese Bai-Yang-Shu anthracite with coal tar and pitch as binder . The BCNTs and CNFs were characterized by scanning and transmission electron microscopy, energy dispersive spectroscopy, and Xray diffraction. It is found that BCNTs and CNFs grow as a deposit on the anode at a low helium pressure of 0.020MPa with the coalbased carbon rod as anode. Most of the BCNTs have an open end and a diameter of 50nm. CNFs with a diameter of 30-50nm form fluffy balls on the surface of the remaining anode.