Microwave irradiated N- and B,Cl-doped graphene: Oxidation method has strong influence on capacitive behavior

Graphene and its derivatives show promising potential in future capacitor systems due to their excellent conductivity and large surface area. Here, we study the effect of different graphite oxidation methods (i.e., Staudenmaier, Hummers, and Hoffman methods) on the capacitive behavior of heteroatom-doped graphene. After graphite oxidation, the graphene materials were simultaneously doped, exfoliated, and reduced using microwave irradiation in BCl3 and NH3 atmospheres to produce B,Cl- and N-doped graphene. Our findings show that the graphite oxidation method employed plays a strong influence on their doping levels, which in turn affects their capacitive behavior. The capacitance result correlates well with the amount of doping achieved. The heteroatom-doped graphene prepared here via Hummers and Hoffman oxidation routes prove superior compared to the Staudenmaier method. (C) 2017 Published by Elsevier Ltd.