Modification of graphene with nitrogen and oxygen via radical reactions with simple mechanical treatment

It is of fundamental and industrial interest to develop a facile method to modify the graphene sheets with het-eroatoms such as oxygen (O) and nitrogen (N). Herein, the O and N atoms were discovered to be grafted onto the edges of graphene sheets during the simple grinding process with solvent in air or N2 atmosphere. By combining X-ray photoelectron spectroscopy (XPS), high resolution transmission electron microscope (HRTEM), energy dispersive X-ray spectrometer (EDS), electron spin resonance spectroscopy (ESR) and H2O2 experiments, we show where the O and N atoms were grafted and how the modification of graphene with O and N atoms occurred. The results showed that the O atoms of air and N atoms of solvent molecules could be bonded to the edges of graphene sheets during the grinding process, which followed the radical reaction mechanism.