Carbon-doped Carbon Nanotubes Preparation And Properties Of Research

Carbon, CNx, BCN , Ga-doped and B-doped nanotubes, synthesized by pyrolysis are studied by SEM, TEM and Roman spectroscopy. The diameter of multiwalled carbon nanotubes produced with the catalyzer of Ni/ ferrocene was about 50nm which that of CNx nanotubes with "bamboo-like"structure and crooked surface ranges from 15 to 60nm. "bamboo-like" structure is more abvious in BCN nanotubes and the distances between neatest nodes are equal. The diameter is about 50nm and the thickenss of the wall is about 7nm. BCN nanotubes are pure. Ga-doped carbon nanotubes are groovy with little crooked surface. Its diameter ranges from 30 to 70nm. That the content of Ga in the tubes is less than 1% . The B-doped carbon nanotubes about 20μm in length and 30-100nm in diameter have the "bamboo-like" structure.Thin films of the purified samples are fabricated by a screen-printing method. The field emission effect of these films are compared. It is found that the turn-on field of the Carbon, CN_x, BCN , Ga-doped and B-doped nanotubes is 2.22, 1.1, 4.4 , 1.0 and 2.1 V/μm, and the current density at 5.7V/μm is 1400, 3000 and <50μA/cm~2 for C, CN_X and BCN nanotubes, respectively. The current density equate as large as 5000μA/cm~2 at 2.6 V/μm for Ga-dopping carbon nanotubes. The current density equate as large as 2000μA/cm~2 at 3.5V/μm for B-doped carbon nanotubes.We can find The electron field emission property of Ga-doped carbon nanotubes is best.