The graphitization of carbon nanofibers produced by catalytic decomposition of methane: Synergetic effect of the inherent Ni and Si

The catalytic effect of the inherent Ni and Si on the graphitization of carbon nanofibers produced by catalytic decomposition of methane is reported. The participation of the inherent Ni and Si metals as co-catalysts in the graphitization of the carbon nanofibers through the formation of Ni(2)Si and SiC was inferred. Taking advantage of this catalytic effect, graphite materials showing structural characteristics comparable to oil-derived graphites which are employed in several industrial applications have been prepared from the carbon nanofibers. Unlike SiC which is further descomposed to graphite, the role of Ni(2)Si remains unclear. At the CNFs heat treatment temperatures employed, Ni(2)Si is in a liquid state where the carbon can be dissolved to form a supersaturated solution from which the SiC can be produced by segregation, thus being an intermediate stage in the catalytic graphitization of the carbon nanofibers. Further work are currently in progress to go insight this issue. (C) 2010 Elsevier Ltd. All rights reserved.