ON THE MECHANISM OF SINGLE-WALL CARBON NANOTUBE NUCLEATION IN THE ARC AND LASER PROCESSES: WHY BIMETALLIC CATALYSTS HAVE HIGH EFFICIENCY?

摘要

A new model of SWNT nucleation has been proposed in which an endohedral metallofullerene serves as the precursor of a nanotube nucleus, and the nucleus itself is formed as an adduct arising when metal atoms attach to the endofullerene shell. High efficiency of bimetallic catalysts is explained by double action of the metal catalyst in SWNT nucleation. First, one metal helps to create the formation of endometallofullerenes. Secondly, the other metal atoms attach to the endofullerene shell to transform an endofullerene into a nanotube nucleus. The relative efficiencies of La/Ni, Gd/Ni, Ce/Ni, Pr/Ni catalysts, in comparison to Y/Ni catalyst were measured and their high efficiency in SWNT formation has been demonstrated.