Multi-wall carbon nanotubes were exposed to a CF4 radio-frequency plasma. High-resolution photo-electron spectroscopy showed that the treatment effectively grafted fluorine atoms onto the multi-walled carbon nanotubes, altering the valence electronic states. The F surface concentration could be tuned by varying the exposure time. Evaporation of gold onto multi-walled carbon nanotubes was used to mark active site formation. High-resolution transmission electron microscopy coupled with density functional theory modeling was used to characterize the surface defects formed, indicating that the plasma treatment did not etch the tube surface. It was suggested that this combination of theory and microscopy of thermally evaporated gold atoms onto the carbon nanotube surface could be a powerful approach to characterizing both surface defect density as well as defect type.

Spectroscopy and Defect Identification for Fluorinated Carbon Nanotubes. C.Bittencourt, G.Van Lier, X.Ke, I.Suarez-Martinez, A.Felten, J.Ghijsen, G.Van Tendeloo, C.P.Ewels: ChemPhysChem, 2009, 10[6], 920-5