Coal as a carbon source for carbon nanotube synthesis Review Article

This article reviews the recent advances on the various processes used in the synthesis of carbon nanotubes (CNTs) from different types of coal (anthracite, bituminous, etc.) and on the role played by coal as carbon source in the production of CNTs. The molecular solid coal is inexpensive and widely available in comparison to the most widely used solid carbon precursor, graphite (a lattice solid) and high purity hydrocarbon gas sources. An account is given on the different processes involved in the synthesis of various CNTs (single and multi-walled, bamboo-shaped, branched, etc.) from different types of coal (anthracite, bituminous, etc.). Both arc-discharge and thermal plasma jet produce high quality CNTs but fundamental disadvantages limit their use as large-scale synthesis routes. Chemical vapour deposition appears to be promising but further experimental work is necessary in order to develop an understanding of the complex factors governing the formation of different carbon nanomaterials from coal. Successful utilization of CNTs in various applications is strongly dependent on the development of simple, efficient and inexpensive technology for mass production and coal as a carbon source has the potential to meet the needs.