Formation of Y-junction carbon nanotubes by catalytic CVD of methane

Y-junction carbon nanotubes were grown by catalytic CVD of methane at 700 degrees C on NiO-CuO-MoO(7:2:1)(w/w/w)/SiO2 catalyst. For comparison, NiO-CuO(8:2)(w/w)/SiO2 and NiO-MoO(8:2)(w/w)/SiO2 catalysts were tested for carbon nanotube formation. TEM analysis indicates that no Y-junction structures were formed with the latter two catalysts. This finding elucidates why the addition of a small amount of Moo to NiO-CuO/SiO2 catalyst is crucial for enhancing the formation of Y-junction carbon nanotubes. (c) 2006 Elsevier Ltd. All rights reserved.