High yield and quality mutli-walled carbon nanotube (MWNT) bundles and carbon nanofibers were synthesized by catalytic decomposition of methane over Co/MgMoO4 catalyst at 1 000 ℃. TEM studies showed that the products...High yield and quality mutli-walled carbon nanotube (MWNT) bundles and carbon nanofibers were synthesized by catalytic decomposition of methane over Co/MgMoO4 catalyst at 1 000 ℃. TEM studies showed that the products were mainly carbon nanofibers without carrier gas and were all MWNT bundles with hydrogen or nitrogen as carrier gas. Thermal gravimetric analyses (TGA) on the raw product indicated that the purity of MWNT was higher than 95wt%. The growth mechanism of carbon nanofibers and MWNTs was also discussed.展开更多
Fe-Mo-Mg-O catalyst prepared by combustion method has great efficiency to grow carbon nanotubes with CVD method. Through investigation of TEM, it is found that bundles of multi-wall carbon nanotubes (MWCNT) can be got...Fe-Mo-Mg-O catalyst prepared by combustion method has great efficiency to grow carbon nanotubes with CVD method. Through investigation of TEM, it is found that bundles of multi-wall carbon nanotubes (MWCNT) can be got when the catalyst is directly used to synthesize the product in CH 4/H 2 atmosphere; however, the dispersed carbon nanotubes are obtained while the catalyst is reduced firstly in the H 2 before the synthesis. The morphology and structure of the catalysts before and after reduced are analyzed by TEM and XRD. The growth mechanism is suggeested for the formation off these two kinds of carbon nanotubes.展开更多
文摘High yield and quality mutli-walled carbon nanotube (MWNT) bundles and carbon nanofibers were synthesized by catalytic decomposition of methane over Co/MgMoO4 catalyst at 1 000 ℃. TEM studies showed that the products were mainly carbon nanofibers without carrier gas and were all MWNT bundles with hydrogen or nitrogen as carrier gas. Thermal gravimetric analyses (TGA) on the raw product indicated that the purity of MWNT was higher than 95wt%. The growth mechanism of carbon nanofibers and MWNTs was also discussed.
文摘Fe-Mo-Mg-O catalyst prepared by combustion method has great efficiency to grow carbon nanotubes with CVD method. Through investigation of TEM, it is found that bundles of multi-wall carbon nanotubes (MWCNT) can be got when the catalyst is directly used to synthesize the product in CH 4/H 2 atmosphere; however, the dispersed carbon nanotubes are obtained while the catalyst is reduced firstly in the H 2 before the synthesis. The morphology and structure of the catalysts before and after reduced are analyzed by TEM and XRD. The growth mechanism is suggeested for the formation off these two kinds of carbon nanotubes.
