Dependence of SWNT Growth Mechanism on Temperature and Catalyst Particle Size: Bulk versus Surface Diffusion

TL;DR

This study uses MD simulations to compare SWNT growth mechanisms on solid and liquid metal catalysts, revealing that surface diffusion dominates on solid particles while bulk diffusion is prevalent on liquid ones.

Contribution

It demonstrates the dependence of SWNT growth mechanisms on catalyst particle state, highlighting the role of surface versus bulk diffusion in the process.

Findings

Surface diffusion dominates on solid catalyst particles.

Bulk diffusion is the primary mechanism on liquid catalyst particles.

Growth mechanisms vary significantly with catalyst particle state.

Abstract

MD simulations reveal that many aspects of SWNT nucleation and growth from solid and liquid metal particles are similar. In both cases graphitic islands lift off the cluster surface to form caps that grow into SWNTs. However, in contrast to liquid particles, where C atoms primarily diffuse into the bulk of the cluster before adding to the growing SWNT, incorporation of C into SWNTs on solid particles occurs predominantly via surface diffusion.