Fabrication And Characterization Of Metal/oxide-carbon Nanotube Composites

Various materials can be adsorbed or encapsulated in the special one-dimension inner cavity of carbon nanotubes. And nanostructure composites are obtained by the confined reaction. The hybrid materials based on carbon nanotubes have become an area of significant interest in recent years. In the presented paper, metal/metal oxide particles were respectively combined with multi-wall carbon nanotube to form novel nano-composites by various methods. The obtained composites were characterized using HRTEM, XRD and Raman spectrum.Carbon nanotubes were treated with concentrated HNO3, mixture of concentrated H2SO4 and concentrated HNO3 (3﹕1 by volume), mixture of concentrated H2SO4 and K2Cr2O7 (1﹕1 by volume). Typical TEM images of the opened nanotubes were observed. Although all these oxidants effectively opened the nanotubes, sonicated with concentrated HNO3 seems to be a better procedure.Magnetic muti-wall carbon nanotube composites were obtained by decoration of metal oxide nanoparticles on or in carbon nanotubes. The method involved the dispersion of the carbon nanotubes in iron pentacarbonyl Fe (CO)5 followed by vacuum thermolysis and subsequent oxidation. The magnetic iron oxide particle deposition was always homogeneous and could be controlled selectively on outer, inner, or both surfaces of MWCNTs by using different MWCNTs. Since the hollow channels remained intact, these MWCNT based composites could find special applications in cellular delivery systems.W-MWCNT composites have been successfully prepared via the pyrolysis of tungsten carbonyl in the presence of carbon nanotubes. It has been suggested that tungsten nanowires are high efficient field electron emitters, and carbon nanotubes were suggested recently for low-voltage field emission. It can be expected that the resulting composites will possess perfect field electron emission properties by incorporating tungsten with carbon nanotubes.A general method was proposed. This method could be used to obtain various metals/oxides-MWCNT composites by simply substituting the metal carbonyl precursors.