Covalent sidewall functionalization of single-walled carbon nanotubes via one-electron reduction of benzophenone by potassium

We reported a method for covalent sidewall functionalization of single-walled carbon nanotubes via one-electron reduction of benzophenone by potassium. The reaction of a potassium atom with a benzophenone molecule results in transferring one electron from the potassium to the benzophenone, forming a radical anion, which adds readily to nanotubes. Raman and UV–vis spectroscopy confirm unambiguously that covalent functionalization has taken place. ATR-FTIR spectroscopy shows that diphenylcarbinol groups have been grafted onto the sidewalls of nanotubes. The degree of functionalization was measured by thermogravimetric analysis (TGA).