A diameter-selective attack of metallic carbon nanotubes by nitronium ions.
We have found a method for a diameter-selective removal of metallic single-walled carbon nanotubes (m-SWCNTs) from semiconducting (s-) ones by stirring or sonicating SWCNT powder in tetramethylene sulfone (TMS)/chloroform solution with nitronium hexafluoroantimonate (NO2SbF6: NHFA) and nitronium tetrafluoroborate (NO2BF4: NTFB). Positively charged nitronium ions (NO2+) were intercalated into nanotube bundles, where the intercalation was promoted also by the counterions. Nitronium ions selectively attacked the sidewall of the m-SWCNTs due to the abundant presence of electron density at the Fermi level, thus yielding stronger binding energy as compared to the counterpart s-SWCNTs. The s-SWCNTs were left on the filter after filtration, whereas the m-SWCNTs were disintegrated and drained away as amorphous carbons. The effectiveness of removing m-SWCNTs was confirmed by the resonant Raman spectra and absorption spectra.
An
Kay Hyeok
KH
BK21 Physics Division, Institute of Basic Science, Center for Nanotubes and Nanostructured Composites, Sungkyunkwan University, Suwon 440-746, Korea.
Park
Jin Sung
JS
Yang
Cheol-Min
CM
Jeong
Seung Yol
SY
Lim
Seong Chu
SC
Kang
Chul
C
Son
Joo-Hiuk
JH
Jeong
Mun Seok
MS
Lee
Young Hee
YH