Exploring the effect of magnesium oxide on electrochemical properties of polypyrrole encapsulated on graphitic carbon nitride for supercapacitors applications

Abstract

This study addresses the facile synthesis of magnesium oxide/graphitic carbon nitride/Polpyrrole (MGP) composites by varying the concentration of magnesium oxide. These composites were synthesized via calcination route followed by in-situ polymerization reaction thus naming the composites as MGP0.5, MGP1, MGP2 and MGP3. The structural analysis of composites is done through X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Raman spectroscopy while the morphology is analyzed through Field Emission Scanning Electron Microscopy (FESEM) and supported by Transmission Electron Microscopy (TEM). The MGP2 composite, assessed through multi-point BET theory, exhibits a specific surface area of 109.45 m² g⁻¹, surpassing that of its precursor materials. This enhanced surface area facilitates a greater number of active sites for the adsorption-desorption of ions. The assessment of electrochemical properties is done through cyclic voltammetry (CV), galvanostatic charge discharge (GCD) and electrochemical impedance spectroscopy (EIS) in three-electrode setup in 1 M H₂SO₄ which delivers a specific capacitance of 1132.12 F g⁻¹ at 5 mV s⁻¹ for MGP2 composite. The practical applicability of the electrode material was examined by fabricating an asymmetric supercapacitor device which delivers an energy density of 9.25 W h kg⁻¹ at a power density of 302.72 W kg⁻¹. The supercapacitor device exhibited 94.03 % capacitance retention after 10,000 cycles demonstrating its potential to be used as a future supercapacitor applications.