Carbon nanotubes (CNTs) have been rigorously studied during the past decade due to their extraordinary physical, chemical, mechanical, electrical and optical properties and nanosized catalysts plays an important role in the growth rate, purity and structural properties of the CNTs. In this paper we discuss various methods for the preparation of nanosized catalyst particles including electron bombardment, dc-sputtering, and magnetron sputtering, sol-gel and dip dry method in context to CNT synthesis. These methods are presented in a simplified manner so that the mechanism of formation of nanosized material can be illustrated. It is found that physical methods such as electron bombardment, dc-sputtering and magnetron sputtering prepare nanoparticles without any contamination; where as chemical methods such as sol-gel and dip dry methods are simplest and cheapest for the preparation of nanosized catalysts. Moreover, sol-gel method prepares monodisperse catalyst nanoparticles.
Carbon nanotubes, Nanosized catalysts, Physical vapour deposition method, Magnetron sputtering, Dc-s