Extrinsic Pseudocapacitive NiSe/rGO/g-C₃N₄ Nanocomposite for High-Performance Hybrid Supercapacitors

Abstract

Battery-type materials with ultrahigh energy density show great potential for hybrid supercapacitors (HSCs). In this work, we have developed a nickel selenide (NiSe)/reduced graphene oxide (rGO)/graphitic carbon nitride (g-C 3 N 4 ) ternary composite as a promising positive electrode for hybrid supercapacitors (HSCs). The extended π-conjugated planar layers of g-C 3 N 4 promote strong interconnectivity with rGO, which further enhances surface area, surface free energy, and efficient electron/ ionic path. Additionally, it establishes clear ion diffusion pathways, serving as ion reservoirs during charge and discharge and facilitating efficient redox reactions. As a result, the NiSe/g-C 3 N 4 /rGO nanocomposite electrode displayed a specific capacity of 412.6 mA h g −1 at 1 A g −1 . Later, the HSC device was assembled using the nanocomposite as the positive electrode and activated carbon as the negative electrode, which delivered an energy density of 65.2 Wh kg −1 at a power density of 750 W kg −1 . Notably, the HSC device maintained excellent cyclic stability, preserving 93.3% of its initial performance and Coulombic efficiency of 86.6% for 10,000 charge−discharge cycles at 5 A g −1 . These findings underscore the potential utility of NiSe/g-C 3 N 4 /rGO as a versatile and effective electrode material for the strategic development of HSC devices.

Triggering Redox Active Sites Through Electronic Structure Modulation in rGO Encapsulated Mixed Transition Metal Oxides Hybrid for Alkaline Hydrogen Evolution

“…The R CT value is directly related to the semicircle diameter of the Nyquist plot . Among various coatings under investigation, the ternary coating possesses an R CT of 545.3 Ω, the binary coating has 984.2 Ω, and the bare NiFeP coating has 1875 Ω.…”

In situ growth of NiSe2 nanoparticles on g-C3N4 nanosheets for an efficient hydrogen evolution reaction

“…19,20 The g-C 3 N 4 enhances the interaction with materials by providing N sites, resulting in abundant active sites, optimized electronic states, and rapid mass/charge transfer. 21,22…”