On the preparation of Ni-carboxylates catalysts for growing single walled carbon nanotubes

[[abstract]]A pretreatment process, which can convert the Ni-carboxylates into high performance Ni-cluster catalysts, is developed. The environment in heat treatment process is observed to markedly alter the catalytic behavior of the obtained Ni-clusters. The beneficial effect of using the carbonizing atmosphere (CH4/N2=150/150 sccm) in the heat treatment process is the formation of encapsulating carbonaceous layer around the Ni-clusters, which prevents the coalescence, yet maintaining the high catalytic activity for the Ni-clusters. Such kinds of Ni-clusters facilitate the growth of defectless CNTs, which contain mostly hexagons.[[notice]]補正完