▎ 摘　　要

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.