Synthesis and Electrochemical Evaluation of CuO/ZnO @Hierarchical Porous Graphitic Carbon Spheres for Enhanced Supercapacitive Applications

In this study, CuO/ZnO@hierarchical porous graphitic carbon spheres (CuO/ZnO@HPGCS) nanocomposites were synthesized via a cost-effective low-temperature water-bath technique. Chitosan was employed as a carbon precursor, while PVP and PEG acted as stabilizing agents to ensure the formation of well-structured porous carbon spheres. Comprehensive characterization techniques, including scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDX), were utilized to analyze the morphology, structure, and elemental composition of the synthesized materials. The electrochemical behavior of the CuO/ZnO@HPGCS electrodes was evaluated using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS). Compared to pure CuO/ZnO and standalone HPGCS electrodes, the CuO/ZnO@HPGCS nanocomposites exhibited significantly improved supercapacitive performance. The specific capacitance of CuO/ZnO@HPGCS reached an impressive 1875 F/g at a scan rate of 10 mV/s, substantially outperforming CuO/ZnO (1229 F/g) and HPGCS (798 F/g). This enhancement can be attributed to the synergistic effect between the high conductivity and large surface area of HPGCS and the electroactive properties of transition metal oxides. The porous structure of HPGCS provided ample active sites and improved charge transfer dynamics, thereby boosting the overall electrochemical performance. The study demonstrates the potential of CuO/ZnO@HPGCS nanocomposites as advanced materials for energy storage applications, offering a scalable and cost-efficient approach to fabricating high-performance supercapacitor electrodes for industrial and commercial use.