6533b7d7fe1ef96bd126852d
RESEARCH PRODUCT
Local photo-oxidation of individual single walled carbon nanotubes probed by femtosecond four wave mixing imaging
Jukka AumanenPasi MyllyperkiöOlli HerranenMika PetterssonAndreas Johanssonsubject
NanotubeMaterials scienceta114mixing imaginglocal photo-oxidationAnalytical chemistryGeneral Physics and AstronomyCarbon nanotubelaw.inventionsymbols.namesakeFour-wave mixinglawindividual single walled carbon nanotubesFemtosecondMicroscopysymbolsIrradiationPhysical and Theoretical Chemistryfour waveRaman spectroscopyInert gasta116femtoseconddescription
Photo-oxidation of individual, air-suspended single walled carbon nanotubes (SWCNTs) is studied by femtosecond laser spectroscopy and imaging. Individual SWCNTs are imaged by four wave mixing (FWM) microscopy under an inert gas (Ar or N2) atmosphere. When imaging is performed in an ambient air atmosphere, the decay of the FWM signal takes place. Electron microscopy shows that SWCNTs are not destroyed and the process is attributed to photoinduced oxidation reactions which proceed via a non-linear excitation mechanism, when irradiation is performed with ∼30 fs pulses in the visible spectral region (500-600 nm). Photo-oxidation can be localized in specific regions of SWCNTs within optical resolution (∼300 nm). The effect of photo-oxidation on Raman spectra was studied by irradiating a local spot on an individual SWCNT and comparing the spectra of irradiated and non-irradiated regions of the same tube. It is shown at an individual nanotube level that oxidation leads to a decrease of the intensity of the Raman signal and an upshift of the G-band.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2014-11-11 | Physical Chemistry Chemical Physics |