One-pot hydrothermal synthesis of MWCNTs/NiS/graphitic carbon nitride as next generation asymmetric supercapacitors

Abstract

Fabricating new electrode materials with high capacitive properties is crucial in contemporary research. The construction of hybrid supercapacitors developed using transition metal-sulfides and carbonaceous materials provides significant surface area and distinctive charge storage characteristics. In the present work, NH2-multiwalled carbon nanotubes/NiS/g-C3N4 (MNG) hybrid was synthesized by a one-pot hydrothermal method, and pristine g-C3N4 using thermal method. The morphological studies of the hybrid materials show the presence of tube like MWCNTs, sphere-like NiS, and sheet like g-C3N4. The uniform distribution of all the components in the hybrid helps in exhibiting excellent electrochemical performances. The prepared electrode material shows a specific capacitance of 2432 F g−1 at a current density of 4 A g−1. Furthermore, following a series of 10,000 cycling tests, the hybrid ternary composite retains 98 % of its initial capacitance. An asymmetric coin cell of MNG//AC was fabricated with an exceptional energy density of 73.3 Wh kg−1 and a power density of 1599.2 W kg−1. This remarkable rate performance and cycle stability exhibited by the material indicate its potential as a highly efficient electrode material for supercapacitors.