Synthesis of carbon nanotubes on metal alloy substrates with voltage bias in methane inverse diffusion flames

• Published in: Carbon (New York) Vol. 44; no. 3; pp. 570 - 577
• Main Authors: Xu, Fusheng, Liu, Xiaofei, Tse, Stephen D.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.03.2006; Elsevier Science
• Subjects: Carbon nanotubes; Catalysis; Catalytically grown carbon; Chemistry; Combustion; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Fullerenes and related materials; diamonds, graphite; General and physical chemistry; Materials science; Physics; Raman spectroscopy; Specific materials; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Carbon nanotubes; Combustion; Catalytically grown carbon; Raman spectroscopy; Methane; Composition; Catalytic reaction; Growth rate; Growth; Alloys; Fuels; Carbon; Precursor; Substrates; Synthesis; Diffusion flame; Multiwalled nanotube; Morphology; Jets; Inverse; Gas phase; Sampling; Structure; Diameter
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2005.07.043

Vertically well-aligned multi-walled carbon nanotubes (MWNTs) with uniform diameters (∼15 nm) were grown on catalytic probes at high yield rates in an inverse diffusion flame (IDF) of a co-flow jet configuration using methane as fuel. Varied parameters investigated included: alloy composition (e.g. Fe, Ni/Cu, Ni/Cr/Fe), sampling positions within the flame structure, and voltage bias applied to the probe substrate. Spontaneous Raman spectroscopy was utilized to determine the local gas-phase temperature, as well as the concentrations of carbon-based precursor species (e.g. CO, C 2H 2) within the flame structure at specific locations of carbon nanotube (CNT) growth during synthesis. The variation of the aforementioned parameters strongly affects CNT formation, diameter, growth rate, and morphology.