Fluorination of multiwall carbon nanotubes by a mild fluorinating reagent HPF6

Multiwall carbon nanotubes (MWCNTs) have been fluorinated by using a mild fluorinating agent HPF6 at different temperatures starting from room temperature to 150 °C to study the effects of reaction temperature on the surface of MWCNTs. The fluorine content increases with increasing reaction temperature. The analysis of Fourier transform infrared (FTIR) and X-ray photo electron spectra (XPS) has pointed out clearly to the formation of chemical bonding between fluorine and carbon atoms on the surface of MWCNTs. Smaller amounts of CF2 and CF3 have been bonded primarily at various defect sites of MWCNTs. The XPS result shows that CF0.018 stoichiometry composition is attained in this fluorination reaction at 150 °C. The stability of the fluorinated MWCNT has been examined by thermogravimetric analysis. It shows that the largest fluorine loss occurred between 200 °C and 400 °C. TEM image indicates that the raw nanotube structure is preserved after fluorination at temperature 150 °C.