Synergistic microwave-assisted synthesised BiCoO/ <i>β</i> -Bi ₂ O ₃ nanocomposites as an electrode material for high-performance supercapacitor

Abstract In this work, a BiCoO/ β -Bi 2 O 3 nanocomposite was produced through a microwave-assisted method, which enabled them to produce the material rapidly while consuming less energy, and then they tested it as a supercapacitor(SC) electrode material. XRD structural analysis established that the material contained mixed phases with tetragonal β -Bi 2 O 3 and cubic BiCoO, creating a distinct heterostructure, which FTIR confirmed through its detection of specific metal–oxygen bonds. FESEM analysis revealed a hierarchical architecture composed of interconnected nanosheets and nanoparticles, which provided the material with multiple electroactive sites. The electrochemical test revealed strong pseudocapacitive behaviour, which produced a specific capacitance value of 664.8 F g −1 at 0.8 A g −1 . The electrode demonstrated excellent rate performance together with minimal internal resistance according to galvanostatic charge–discharge and electrochemical impedance spectroscopy testing results. The nanocomposite demonstrated excellent cycling performance, which allowed it to maintain 91.18% of its capacitance retention after 3000 cycles, while achieving a 91.41% coulombic efficiency. A symmetric device fabricated using the material, which provides appreciable energy and power densities, thus proving its potential for practical use. The BiCoO/ β -Bi 2 O 3 nanocomposite functions as a highly efficient and long-lasting electrode material, which shows promise for advanced SC applications.