Enhancing Supercapacitor Performance Using Co-doped Biochar Embedded on Oxide Metal/polyaniline Ternary Composite as Electrode Materials

We report a promising source of electrode materials, derived from orange peels (OPs) embedded Co-doped MnO₂ and wrapped by polyaniline (PAni) were prepared by simple facile chemical synthesis route. Physicochemical character of the ternary composites was investigated by XPS, XRD, FTIR, TGA, UV–Vis, TEM and gas sorption analysis. The formation of benzenoid ring and quinoid ring of the polyaniline (PAni) system were confirmed by FT–IR spectra. XRD spectrum confirms the amorphous nature of the electrode samples. The XPS results confirm the presence of some interactions between PAni, Mg and Co into OPs surface. The optical absorption spectrum reveals the presence of three absorption peaks attributed to the π–π*, bipolaron and n–π* transitions of the PAni rings, respectively. TEM images showed the dispersion of PAni matrix on the support composites surface. BET analysis indicated the electrodes as-prepared possesses porous structure with higher surface area. TGA studies revealed that the thermal stability of the PAni backbone is enhanced in the hybrid electrodes. Co-doping of MnO₂ by through the preparation process of electrode composite led to a significant change in the supercapacitive properties of the investigated sample. The electrochemical phenomena of electrodes were studied by cyclic voltammetry (CV), galvanostatic charge–discharge and electrochemical impedance measurements in 1 M H₂SO₄ solution. The O/C-M/P electrode exhibited maximum specific capacitance of 609.6 F.g^− 1 with energy and power density values 27.5 Wh.kg^− 1 and 782.3 W.kg^− 1 at 1.0 A.g^− 1 and shows a remarkable adherence with excellent stability of > 90% capacitance retention after 8000 cycles.