In the present work, tert-butylhydroquinone (TBHQ) was used to decorate graphene nanosheets to obtain a novel and environmentally friendly electrode material for supercapacitors. The fast redox reactions between hydroquinone and quinone generate pseudocapacitance. Graphene layers which have adsorbed TBHQ interact with each other to construct a three-dimensional network. Through this network, electrolyte ions can easily access the surface of graphene to generate electric double-layer capacitance. Electrochemical measurements have shown that using TBHQ as a redox modifier of graphene can obtain a maximum value of 302 F g -1 and provide a 51% enhancement in specific capacitance. Furthermore, excellent rate capability and cycling ability are achieved using the TBHQ-decorated graphene nanosheet electrode. To improve the capacitive behavior of graphene-based materials further, only a few studies have investigated the use of graphene coupled with conducting polymers [8][9][10][11]. Also, some researchers are trying to introduce the transition metal oxides/hydroxides with high theoretical specific capacitances into graphene systems [12][13][14][15][16]. In particular, Ni(OH) 2 hexagonal nanoplates grown on graphene sheets have shown both high-power and energy capabilities [17]. However, inorganic materials are non-renewable. Their excessive consumption usually causes a series of environmental problems. There are some organic molecules with reversible electrochemical redox couples that could generate pseudocapacitance under a set of given conditions. For instance, 2-nitro-1-naphthol and anthraquinone have been introduced into carbon black [18] and carbon fabric [19], respectively. In the former case, voltammetric and impedance data obtained in a conventional three-electrode cell were reported, but the modified carbon black was not evaluated as a supercapacitor. In the latter case, the use of anthraquinone as a
Graphene