Catalytic growth of carbon nanotubes over Ni/Cr hydrotalcite-type anionic clay and their hydrogen storage properties

Carbon nanotubes have been prepared by the catalytic decomposition of acetylene over Ni/Cr hydrotalcite-type anionic clay catalyst. Ni/Cr hydrotalcite-type anionic clay precursors have been prepared by co-precipitation technique. The role of stability of Ni nanoparticles obtained in situ from the decomposition of the catalyst on the growth of MWNTs is discussed. The assynthesized and purified carbon nanotubes are characterized by thermogravimetry, IR spectroscopy, X-ray diffraction, BET analysis, scanning electron microscopy, transmission electron microscopy and Raman spectroscopy measurements. The hydrogen adsorption capacity of as-synthesized and purified multiwalled carbon nanotubes at 298 K has been obtained using a high-pressure hydrogen adsorption set-up and the results are discussed