Structure and dynamics of metallic and carburized catalytic Ni nanoparticles: effects on growth of single-walled carbon nanotubes

Abstract

Understanding the evolution of the catalyst structure and interactions with the nascent nanotube under typical chemical vapor deposition (CVD) conditions for the synthesis of single-walled carbon nanotubes is an essential step to discover a way to guide growth toward desired chiralities. We use density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulations on model metallic and carburized Ni clusters to explore changes in the fundamental features of the nanocatalyst: geometric and electronic structure, dynamics and stability of the carburized nanocatalyst, and interactions with nascent nanotube caps at two different temperatures (750 and 1000 K) and different carbon composition ratios. This allows us to gain insight about the evolution of these aspects during the pre-growth and growth stages of CVD synthesis of single-walled carbon nanotubes and their implications for reactivity and control of the nanotube structure.