Temperature tuned carbon morphologies derived from flexible graphite sheets in KNO3 molten salt

Carbon nanomaterials with different morphologies were prepared by thermal treatment of a flexible graphite sheet in KNO3 molten salt. Transmission electron microscopy was used to observe the morphologies. Porous graphene, carbon nanocages and carbon nanospheres were obtained on increasing the temperature from 350 to 600 °C. The formation mechanisms of different carbon morphologies are discussed.