Chemical and Physical State of Catalysts in the Growth of Single-Walled Carbon Nanotubes inside Metallocene-Filled Single-Walled Carbon Nanotubes

Abstract

In this study, the state of catalysts is revealed during the growth of single-walled carbon nanotubes (SWCNTs) inside metallocene-filled SWCNTs. High-resolution transmission electron microscopy and Raman spectroscopy were used to study the kinetics of nanotube growth. Raman spectroscopy and X-ray photoelectron spectroscopy were employed to study the chemical state of catalysts inside carbon nanotubes. The catalyst was present in carbidic form at the beginning of nanotube growth, and was present in a metallic state over the continuation of the growth process. The growth process was characterized by two growth rates, α and β, and two activation energies, Eα and Eβ.

Keywords

• carbon nanotube
• growth kinetics
• metal
• metal carbide
• chemical state
• physical state