Fe-Substituted Mullite Powders for the In Situ Synthesis of Carbon Nanotubes by Catalytic Chemical Vapor Deposition

• Published in: Journal of physical chemistry. C Vol. 113; no. 26; pp. 11239 - 11245
• Main Authors: Resende, Valdirene G. de, Hui, Xu, Laurent, Christophe, Weibel, Alicia, Grave, Eddy De, Peigney, Alain
• Format: Journal Article
• Language: English
• Published: American Chemical Society 02-07-2009
• Subjects: C: Nanops and Nanostructures; Engineering Sciences; Materials; Carbon nanotubes; Fe-substituted mullite; Catalytic chemical vapor deposition
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp901780f

Powders of iron-substituted mullite were prepared by combustion and further calcination in air at different temperatures. A detailed study involving notably Mössbauer spectroscopy showed that the Fe3+ ions are distributed between the mullite phase and a corundum phase that progressively dissolves into mullite upon the increase in calcination temperature. Carbon nanotube−Fe−mullite nanocomposites were prepared for the first time by a direct method involving a reduction of these powders in H2−CH4 and without any mechanical mixing step. The carbon nanotubes formed by the catalytic decomposition of CH4 on the smallest metal particles are mostly double-walled and multiwalled, although some carbon nanofibers are also observed.