Chirality-controlled synthesis of single-wall carbon nanotubes using vapour-phase epitaxy

Abstract

Chirality-controlled synthesis of single-wall carbon nanotubes with predefined chiralities has been an important but elusive goal for almost two decades. Here we demonstrate a general strategy for producing carbon nanotubes with predefined chiralities by using purified singlechirality nanotubes as seeds for subsequent metal catalyst free growth, resembling vapourphase epitaxy commonly used for semiconductor films. In particular, we have successfully synthesized (7, 6), (6, 5) and (7, 7) nanotubes, and used Raman spectroscopy to show unambiguously that the original chiralities of the nanotube seeds are preserved. Furthermore, we have performed electrical measurements on synthesized individual (7, 6) and (6, 5) nanotubes, confirming their semiconducting nature. The vapour-phase epitaxy approach is found to be highly robust and should enable a wide range of fundamental studies and technological developments.

Design and Synthesis of Carbon Nanotube Segments

“…[35] TheY amago research group reported an alternative synthesis of [8]CPP by applying the platinum-mediated synthesis of cycloarenes developed by Bäuerle and co-workers [36] (Scheme 17). [22] Thecomplexation of 4,4'-bis(trimethylstannyl)biphenyl (80)and Pt(cod)Cl 2 afforded macrocycle 81.…”

Diameter-Specific Growth of Semiconducting SWNT Arrays Using Uniform Mo2C Solid Catalyst

“…Further, the average diameter, 1.20 ± 0.2 nm, corresponds to five types of sSWNTs, that is, (14,4), (13,6), (10,9), (16, 0), or (15,2). However, the kinetic growth rate of a zigzag tube is significantly (10−1000 times) slower than that of other CNTs, 21 so we can safely exclude the existence of zigzag and near-zigzag tubes, the (16, 0) or (15,2) nanotubes, which is in good agreement with the Raman results as mentioned above. One should note that it is possible that one or two of the chiralities dominate in the asgrown s-SWNTs, which is difficult to distinguish in the present work.…”

“…In summary, uniform hexagonal Mo 2 C solid catalyst, obtained from Mo 132 as precursor, selectively catalyzes the scission of C− (15,2), are excluded due to the much slower kinetic growth rate. Only (14,4), (13,6), and (10,9) nanotubes are obtained.…”

Carbon nanomaterials for photovoltaic process

“…Using preformed tubes as the seeds to grow SWNTs of identical chirality was also attempted [85][86][87].…”