Microwave Synthesis of Fe-filled Carbon Nanotubes
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0922-U07-40
Microwave Synthesis of Fe-filled Carbon Nanotubes Oxana Kharissova1, Ubaldo Ortiz2, and Moises Hinojosa2 1 FCFM, UANL, San Nicolas de los Garza, Nuevo Leon, 66450, Mexico 2 UANL, San Nicolas de los Garza, Nuevo Leon, 66450, Mexico
ABSTRACT A highly efficient one-step technique was developed in order obtain long and aligned carbon nanotubes with or without Fe filling. The aligned carbon nanotubes (CNTs) were synthesized by heating ferrocene Fe(C5H5)2 using microwave (MW) irradiation. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) were used to study the growth process of the aligned multi-layer carbon nanotubes. It was found that CNTs have a metal particle at the tip of each tube. This carbon nanostructures promise to become important in fuel cells and in nanoscale engineering of other systems.
INTRODUCTION In recent years, the synthesis of carbon nanotubes (CNTs) has been optimized and different production methods have been developed. Initially, most of CNT´s were synthesized by the arc method which involves graphite vaporization between graphite electrodes in an inert gas flow. This technique was replaced by laser-induced thermal synthesis. Recently, increasing attention has been given to the pyrolytic synthesis from gaseous hydrocarbons (CH4, C2H2, etc) and CO. Preference is given to the catalytic processes which allow the preparation of not only MWNT´s, but also single walled nanotubes (SWNT´s) in relatively high yields [1]. Various methods have been explored to produce fullerenes and nanotubes, for instance, incomplete combustion of benzene or hydrocarbons, pyrolysis2, and dissociation of hydrocarbons in thermal plasma [3,4]. The synthesis of CNT´s is often accompanied by the formation of other forms of carbon (fullerenes, polyhedral particles and amorphous forms of carbon). The Microwave (MW) irradiation technique is widely applied in some areas of nanochemistry [5] and technology to produce and destroy a variety of materials and chemical compounds [6], as well as in study of chemical processes. Its advantages are: rapid heating is simply achieved; the energy is accumulated into the material without surface limitations, the environment does not need to be heated, so energy savings are possible; there is no direct contact between the energy source and the material; heating can be easily automated. The carbon nanotubes are formed at high temperature (>3000 K), low power (
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