Thermophysical study of graphene nanoflakes by differential scanning calorimetry

Combustion heats of graphene nanoflakes (GNFs) of different thicknesses produced by chemical vapor deposition method were measured for the first time by differential scanning calorimetry (DSC) in the temperature range of 303–1273 K. They were found to be lower than that of graphite and increase nonlinearly from 18.8 ± 1.1 to 30.5 ± 1.4 kJ g−1 with decrease in the specific surface area of GNFs from 1730 to 770 m2 g−1. The heat capacity of GNFs was calculated to be higher than that of graphite. The energy diagram for the heat of GNF combustion was proposed based on the literature data and results of DSC, Raman spectroscopy and transmission electron microscopy study. The obtained results expand the scarce thermodynamic data available for graphene-based materials.