Double-walled carbon nanotubes (DWCNTs) have been fluorinated by pure molecular fluorine (F2) at room temperature or 200 °C and a mixture of F2 with hydrogen fluoride (HF) at 200 °C that resulted in products with compositions of CF0.12, CF0.39, and CF0.53 as determined by X-ray photoelectron spectroscopy. The differences in the structures of three kinds of fluorinated DWCNTs were revealed using transmission electron microscopy, Raman scattering, and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. Quantum-chemical modeling of the NEXAFS F K-edge spectra detected a change in the fluorine pattern with the increase of the F2 treatment temperature. The presence of HF in fluorine gas was found to accelerate the fluorination process and cause a partial destruction of outer shells of the DWCNTs.
- double-walled carbon nanotubes
- X-ray photoelectron spectroscopy