Exploration of Cu/g-C3N4 Nanocomposites as a Cost-Effective High-Performance Asymmetric Supercapacitor Electrode Material

This work reports the synthesis, characterization, and electrochemical analysis of composites comprised of copper nanoparticles grafted on graphitic carbon nitride (g-C
₃
N
₄
) for cost-effective, high-performance supercapacitor applications. A facile synthesis method was adopted to impregnate copper nanoparticles over g-C
₃
N
₄
sheets, and structural and morphological characterizations evidenced successful in situ grafting of Cu/g-C
₃
N
₄
. Different electrochemical investigations were accomplished to estimate the supercapacitive behavior of the designed electrode material. These electrochemical analyses unveiled that the designed nanocomposites showed superior electrochemical performances than pristine g-C
₃
N
₄
. The equivalent series resistance of 1.61 Ω was obtained for Cu/g-C
₃
N
₄
, which is lesser than base material g-C
₃
N
₄
sheets (2.19 Ω) from the Nyquist plot of EIS spectra. An asymmetric solid-state supercapacitor was designed, and a specific capacitance of 265.25 Fg
⁻¹
at 0.5 Ag
⁻¹
current density was found, along with an energy density of 36.87 Wh/kg at a power density of 2.50 kW/kg. Moreover, good cyclic consistency of 79.4% capacitance retention was obtained at 5 Ag
⁻¹
at 5000 cycles. These electrochemical performances indicate that Cu/g-C
₃
N
₄
nanocomposites have a vast potential to use in energy storage perspective.