Thermal stability of C–F/C(–F)2 bonds in fluorinated graphene detected by in situ heating infrared spectroscopy

The thermal stability of fluorinated graphene (FG) plays an important role in its application and research, and thus it is necessary to conduct in-depth research on the thermal stability of the C-F bond in FG. Herein, FG with different types and distributions of C-F/C(-F)2 bonds were synthesized, and the correlation between the C-F/C(-F)2 bonds and thermal stability of these FG samples was monitored via in situ heating infrared spectroscopy (in situ FTIR). The stability of the different types and distributions of C-F/C(-F)2 bonds in FG and the temperatures at which these C-F/C(-F)2 bonds were eliminated were determined. In terms of C-F bonds in FG, the most stable type is that in C(-F)2 of perfluorinated FG, followed by the C-F bonds in perfluorinated FG. The thermal stability of isolated C-F bonds and C(-F)2 bonds adjacent to the conjugated structure was the worst, which would be detached from FG at low temperature (≤82 °C). Furthermore, the evolution of the conjugated structures in FG during thermal annealing was also affected by the type and distribution of the C-F bonds.