title: Unexpectedly high yield carbon nanotube synthesis from low-activity carbon feedstocks at high concentrations.
abstract: We report a new direction for highly efficient carbon nanotube (CNT) synthesis where, in place of conventional highly reactive carbon feedstocks at low concentrations, highly stable carbon feedstocks at high concentrations were shown to produce superior yields. We found that a saturated hydrocarbon that is considered to possess a low reactivity, delivered at high concentrations, could achieve an extremely high growth yield (2.5 times that when using ethylene). This result stems from the unique behavior where the CNT yield linearly increased with carbon concentration, in contrast to more reactive carbon feedstocks, where the yield peaks. We propose that the mechanisms for the growth kinetics for high- and low-reactivity carbon feedstocks are fundamentally different, where the latter benefits from a longer catalyst lifetime because of a relatively low production rate of carbon impurities.
authors: Nanotube Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, 305-8565, Japan.
authors: Hiroe
authors: H
authors: Kimura
authors: Jundai
authors: J
authors: Goto
authors: Satoshi
authors: S
authors: Yasuda
authors: Shunsuke
authors: S
authors: Sakurai
authors: Motoo
authors: M
authors: Yumura
authors: Don N
authors: DN
authors: Futaba
authors: Kenji
authors: K
authors: Hata
mesh_terms: D002244:Carbon / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D037742:Nanotubes, Carbon; D002244:Carbon