Effects of Growth Parameters on the Morphology of Aligned Carbon Nanotubes Synthesized by Floating Catalyst and the Growth Model

Abstract

Aligned carbon nanotubes (CNTs) were grown in a simple designed horizontal quartz tube reactor from chemical vapor deposition (CVD) using ferrocene as floating catalyst (FC). FC-CVD process was performed using methane as carbon source under nitrogen flow without introducing hydrogen. Aligned CNTs with an average length of ca. 10 μm were produced at reaction temperatures in a range of 950–1100°C and methane flow rate of 250–450 sccm for 60 minutes. The diameter of CNTs was influenced by the size of iron catalyst particles formed in the reactor. A conceptual model of CNT formation and its growth mechanism were proposed in this study.

Keywords:

• Carbon nanotubes
• floating catalyst
• chemical vapor deposition
• morphology
• vapor growth

Acknowledgments

The authors gratefully acknowledge the financial support provided by the Ministry of Higher Education under Long Term Research Grant Scheme (203/PKT/6723001) and the Universiti Sains Malaysia (USM) Fellowship scholarship under the Research University Grant Scheme (Project A/C No. 814003), the Malaysian Technology Development Corporation (MTDC) under the Commercialization of Research & Development Fund (CRDF) (Project A/C No. MBF065-USM/05) and the Cradle Fund Sdn Bhd under the University-Cradle Investment Program (U-CIP) (Project no: U-CIP-B47).