“…For the last half decade, among several chemical reductants 4,5 , hydrazine has been the most commonly used reductant due to its ease of use (for example, via a one-pot synthesis in either liquid or gas phase) and its ability to achieve a high degree of reduction of graphene oxide without the need for further treatment 3,[6][7][8] . Hydrazine-treated graphene oxide (chemically reduced graphene oxide, 'CReGO') 3 is one of the most promising graphene-based materials for several applications, such as polymer composites, ultracapacitors, rechargeable batteries, chemical/biosensors and thin films [9][10][11][12][13][14] . A large fraction of the oxygen-based functional groups of graphene oxide are removed by exposure to hydrazine; however, the resulting graphene materials contain a small amount of O and N atoms (with approximate C/O and C/N ratios of 10 and 22, respectively) 3,6 .…”