Convert waste petroleum coke to multi-heteroatom self-doped graphene and its application as supercapacitors

Graphene is being suggested as a replacement for activated carbon in energy storage devices ranging from supercapacitors to batteries. The generation of multi-heteroatom self-doped graphene structure from waste materials will be an efficient way to meet the energy requirements with its productive applications in energy devices. Here, we present a novel, high-yield synthetic strategy to prepare multi-heteroatom self-doped highly porous graphene nanosheet from Pet coke (petroleum coke). Following a comprehensive characterization of graphene using electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and its functionality in supercapacitor application is reported. The electrochemical performance of Pet graphene, in combination with 1 M H 2 SO 4 , is able to deliver specific capacitance as high as ~ 170 F/g in 0.5 A/g current density, with low equivalent series resistance. The fabricated symmetric device exhibited a maximum specific capacitance of 44 F/g at 0.5 A/g current density with an excellent energy density of ~ 8.8 Wh/Kg along with a power density of ~ 800 W/Kg at 0.5 A/g current density. The fabricated device also shows high cycling stability and Coulombic efficiency. The results establish a new protocol for the large-scale synthesis of graphene from carbonaceous waste materials, making it competitive with its low-cost counterparts.