Harutyunyan Avetik R, Chen Gugang, Paronyan Tereza M, Pigos Elena M, Kuznetsov Oleg A, Hewaparakrama Kapila, Kim Seung Min, Zakharov Dmitri, Stach Eric A, Sumanasekera Gamini U
Honda Research Institute USA, 1381 Kinnear Road, Columbus, OH 43212, USA.
Science. 2009 Oct 2;326(5949):116-20. doi: 10.1126/science.1177599.
Single-walled carbon nanotubes can be classified as either metallic or semiconducting, depending on their conductivity, which is determined by their chirality. Existing synthesis methods cannot controllably grow nanotubes with a specific type of conductivity. By varying the noble gas ambient during thermal annealing of the catalyst, and in combination with oxidative and reductive species, we altered the fraction of tubes with metallic conductivity from one-third of the population to a maximum of 91%. In situ transmission electron microscopy studies reveal that this variation leads to differences in both morphology and coarsening behavior of the nanoparticles that we used to nucleate nanotubes. These catalyst rearrangements demonstrate that there are correlations between catalyst morphology and resulting nanotube electronic structure and indicate that chiral-selective growth may be possible.
单壁碳纳米管可根据其导电性分为金属型或半导体型，其导电性由手性决定。现有的合成方法无法可控地生长具有特定导电类型的纳米管。通过在催化剂热退火过程中改变惰性气体环境，并结合氧化和还原物种，我们将具有金属导电性的管的比例从总数的三分之一改变到最高91%。原位透射电子显微镜研究表明，这种变化导致了我们用于成核纳米管的纳米颗粒在形态和粗化行为上的差异。这些催化剂重排表明催化剂形态与所得纳米管电子结构之间存在相关性，并表明手性选择性生长可能是可行的。
