CCVD Synthesis of Single- And Double-Walled Carbon Nanotubes: Influence of the Addition of Molybdenum to Fe−Al2O3 Self-Supported Foams

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• 作者：Anne Cordier ; Valdirene G. de Resende ; Eddy De Grave ; Alain Peigney ; Christophe Laurent
• 刊名：Journal of Physical Chemistry C
• 出版年：2008
• 出版时间：December 4, 2008
• 年：2008
• 卷：112
• 期：48
• 页码：18825-18831
• 全文大小：351K
• 年卷期：v.112,no.48(December 4, 2008)
• ISSN：1932-7455

文摘

Powders of α-Al_1.8Fe_0.2O₃ solid solution are prepared by combustion and are attrition-milled with different amounts of ammonium heptamolybdate before being transformed into self-supported foams by impregnation of a polyurethane foam. Carbon nanotubes, mostly single- and double-walled, are prepared by catalytic chemical vapor deposition using the foams as catalytic materials. Extensive characterization reveals that the addition of a small amount of molybdenum first favors the formation of double-walled nanotubes over that of single-walled nanotubes and second activates smaller nanoparticles, thus producing smaller-diameter nanotubes. A detailed Mssbauer spectroscopy study reveals that there is no interaction between iron- and molybdenum species, pointing to a role of molybdenum favoring some phenomenon happening in the gas phase, as opposed to any alloying effect.