Potential Application of Carbon Nanotube Core as a Nanocontainer

Abstract

Multi-walled carbon nanotubes (MWCNTs) with highly ordered graphitization have been synthesized using thermal chemical vapor deposition (CVD) and microwave plasma chemical vapor deposition (MPCVD) techniques. The as-synthesized MWCNTs have a narrow distribution of innermost and outermost tube diameters. MWCNTs have attracted considerable attention from materials scientists and technologists due to their unique one-dimensional structure, through which they acquire electrical, mechanical, and chemical properties. However, so far, the area of utilization of the CNT core as a nanocontainer for synthesizing a single-crystal metal nanorod is still unexplored. In this report, we have developed a rational procedure for the growth of a single-crystal metal nanorod encapsulated inside the CNT core by using a thermal CVD and MPCVD system. We report that despite using a pre-synthesized catalyst in situ, nanoparticle formation due to the plasma etching and surface diffusion of metal atoms leads to the formation of nanosized particles. It is observed that the nature of the growth mechanism depends on the metal–carbon interaction and cohesive energy of the metal catalyst.