Exploration of Cu/g-C<sub>3</sub>N<sub>4</sub> Nanocomposites as a Cost-Effective High-Performance Asymmetric Supercapacitor Electrode Material
Sebina Yesmin, Inamul Hussain, Meghali Devi, Rajdeep Dasgupta, Siddhartha Sankar Dhar
Abstract
This work reports the synthesis, characterization, and electrochemical analysis of composites comprised of copper nanoparticles grafted on graphitic carbon nitride (g-C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> ) for cost-effective, high-performance supercapacitor applications. A facile synthesis method was adopted to impregnate copper nanoparticles over g-C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> sheets, and structural and morphological characterizations evidenced successful in situ grafting of Cu/g-C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> . 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 <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> . The equivalent series resistance of 1.61 Ω was obtained for Cu/g-C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> , which is lesser than base material g-C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> 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 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup> at 0.5 Ag <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup> 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 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup> at 5000 cycles. These electrochemical performances indicate that Cu/g-C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> nanocomposites have a vast potential to use in energy storage perspective.