Eco-friendly synthesis of porous graphene and its utilization as high performance supercapacitor electrode material

The successful application of porous graphene (PG) is hindered due to the lack of efficient and cost-effective method for its synthesis. Herein, we report a facile and eco-friendly method to produce PG through a low temperature solvothermal method. The structural and morphological characteristics of PG samples were investigated thoroughly. The as synthesized material is found to be a few layers thick (-4-6 layers) with a surface area of 420 m(2)g(-1) and consisting of hierarchical pores on the surface of the sheets. A high specific capacitance of 666 F g(-1) was obtained at a scan rate of 5 mV s(-1), apart from longer cyclic stability with 87% retention of initial capacitance value after 10000 cycles for the PG 28 sample. The fabricated supercapacitor displayed an energy density of 26.3 Wh kg(-1) and power density of 6120 W kg(-1). Density functional theory calculations were also carried out to qualitatively support the enhanced capacitance by providing theoretical insight from electronic structure and density of states of PG. These results open a new avenue for greener synthesis of high-quality PG using environmentally friendly solvents, without the use of toxic chemicals, for excellent supercapacitor performance. (C) 2019 Elsevier B.V. All rights reserved.