Direct synthesis of carbon nanotubes decorated with size-controllable Fe nanoparticles encapsulated by graphitic layers

Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, PR China
Carbon (Impact Factor: 6.2). 09/2008; 46(11):1417-1423. DOI: 10.1016/j.carbon.2008.06.021
Source: OAI


A simple method has been developed for direct synthesis of magnetic multi-walled carbon nanotubes (MWCNTs) homogeneously decorated with size-controllable Fe nanoparticles (Fe-NPs) encapsulated by graphitic layers on the MWCNT surface by pyrolysis of ferrocene. These composites have similar C/Fe atomic ratio of ∼10 and exhibit sufficiently high saturation magnetization for magnetic separation in a liquid phase. Moreover, with 0, ∼1, ∼2 wt% sulfur as growth promoter, the size of Fe-NPs can be controlled with an average diameter of ∼5, ∼22 and ∼42 nm, respectively. When compared to time-consuming wet-chemical methods, the simplicity of this method should allow easy large-scale production of these magnetically functionalized MWCNTs, which can be used as catalyst supports with high stability for effective magnetic separation in liquid-phase reactions, especially under acid/basic conditions.

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    • "The addition of negligible amounts of CNTs to metallic and metallic oxide nanofluids opens new ways of obtaining versatile performance characteristics. To date, a much attention has been given to the decoration of CNTs with nanoparticles composed of metals [26] [27] [28], metal oxides [29] [30], or metal sulfides [31] [32] due to the composites' special catalytic [33], electrical, magnetic, thermal, and optical properties [34] [35]. However, very few reports are available on the synthesis of nanofluids with Ag nanoparticles (Ag-NPs) attached to CNTs (Ag/CNTs) [36] [37], which exhibit excellent chemical and physical stability. "
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    • "Metallocenes such as ferrocene have been demonstrated to be used as precursors to prepare carbon nanostructures, because they can not only act as carbon source but also give rise to small metal clusters as catalyst [16] [17] [18]. Here high-quality CSCNTs with short lengths (<3.5 lm) was grown in a quartz tube reactor inside a dual-zone furnace. "
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