Synthesis of nitrogen-doped fullerenes, carbon nanotubes and nanocrystals in nitrogen atmosphere
- 化学化工－已发表论文 
Nitrogen-doped fullerenes, carbon nanotubes and nanocrystals have been synthesized simultaneously for the first time through the are-discharge of graphite electrodes in a pure nitrogen atmosphere. They were prepared in a reaction chamber filled with pure nitrogen gas at the pressures of 10664-53320 Pa. A potential of 20-30 V and a current of 100-140 A ac were applied between two pure graphite rods in the chamber. Nitrogen-doped fullerenes were discovered in soot and characterized by laser desorption mass spectrometry and X-ray photoelectron spectroscopy. Both C-60(-) and C59N- can be observed on laser desorption mass spectrometry. In addition, a series of nitrogen-substituted carbon cluster anions appear on low-mass section bf the mass spectrum. The XPS result also confirms the existence of nitrogen-doped fullerenes. Spectral peaks of C(1s) and N(1s) with binding energies of 288. 1 eV and 402. 8 eV can be distinguished. The latter has a single sharp feature, differing significantly from N, adsorbed on a C-60 film, which produces a spectral peak near 400. 2 eV. Carbon nanotubes were observed in deposit. The deposit formed in a nitrogen atmosphere is much richer in carbon nanotubes than that formed in a helium or argon atmosphere. The carbon nanotubes were investigated by transmission electron microscopy(TEM). Some unusual structural patterns of carbon nanotubes have been observed from the TEM images. In addition, nanocrystals were observed by TEM after the deposit was treated in the corrosive solution. The nanocrystals may be C3N4.