Encapsulation, compensation, and substitution of catalyst particles during continuous growth of carbon nanotubes

TL;DR

This paper investigates the growth mechanism of carbon nanotubes, revealing that catalyst particles are encapsulated from the bottom during continuous growth, which advances understanding and control of CNT synthesis for electronic applications.

Contribution

It provides new insights into catalyst behavior during CNT growth, highlighting encapsulation, compensation, and substitution processes that influence nanotube formation.

Findings

Catalyst particles are encapsulated at the bottom of CNTs during growth.

Active growth sites are located at the bottom of the nanotubes.

Encapsulated catalyst materials can modify electronic and magnetic properties.

Abstract

By sequential feeding of catalyst materials, it is revealed that the active growth sites are at the bottom of the carbon nanotubes (CNTs), and that catalyst particles are constantly encapsulated into nanotubes from the bottom. This gives a better insight into the mechanism of CNT formation and on ways to control the growth process. CNTs encapsulated with different materials should enable the study of their electronic or magnetic properties, with potential applications as building blocks for nanoelectronics and as fillers in composites for electromagenetic shielding.