Metal catalyzed preparation of carbon nanomaterials by hydrogen–oxygen detonation method

Abstract

A hydrogen–oxygen gas detonation was direct initiated by using a 20 J electronic spark, and the pressure and temperature of which were measured by a pressure sensor and high-speed camera, respectively. The results showed the mixed gas was direct initiated in the propagation of detonation wave. The carbon nanomaterials were prepared by decomposition of ferrocene and cobalt (III) acetylacetonate (Co(acac)3), a the samples were characterized by X-ray diffractometer, transmission electron microscope, engergy dispersive X-ray detector and Raman spectrometer. The results indicated that carbon-encapsulated metal nanoparticles were fabricated by using ferrocene, ferrocene–Co(acac)3 as a precursor, and the core–shell nanostructures were carbon-encapsulated Fe/Fe3C nanoparticles (Fe@C) and carbon-encapsulated Co nanoparticles (Co@C). However, the Fe–Co alloy was absent in sample from ferrocene–Co(acac)3. It is interesting that the sample from Co(acac)3 were Co@C and multi-walled carbon nanotubes (MWCNTs), and the crystallization degrees of the carbon and Co nanoparticles in the MWCNTs were higher than that of in carbon-encapsulated metal nanoparticles, however, the degree of graphitization of the powders was low. The physical properties of precursors, hydrogen content and rapid reaction were the main factors which contributed to the different morphologies and the absence of Fe–Co alloy.