Unveiled Supercapacitive Performance of Se‐doped Graphene Nanoarchitectonics Prepared via Supercritical Fluid Technique

Abstract Doping of graphene with variety of heteroatoms is presently focused for electrochemical supercapacitor applications because it functions as a hybrid supercapacitor. Herewith, we report the fabrication of Se‐doped graphene with selenium dioxide using a supercritical fluid technique. Both the existence as well as the quantity of Se‐doping in graphene are established using XPS and EDAX techniques. The Se‐doped graphene derived from the weight ratio of selenium dioxide and graphene oxide of 1 : 3 resulted in an enriched gravimetric capacitance achieving 581 F g⁻¹ (1 M H₂SO₄). The specific capacity of the optimised Se‐doped graphene based symmetric supercapacitor in 0.01 M solution of ammonium metavanadate in 1 M H₂SO₄ solution is found to be 420 C g⁻¹ and attained an improved capacitance retention of 85% over 50000 cycles along with 94% coulombic efficiency. The energy density of the Se‐doped graphene symmetric supercapacitor is found to be 23.33 Wh kg⁻¹ in 0.01 M solution of ammonium metavanadate in 1 M H₂SO₄ solution.