Microstructural and electrochemical properties of Co3O4 porous nanospheres

In this study, Co 3 O 4 porous nanospheres were synthesized at 200 °C using a solution combustion method and subsequently annealed at 600 °C. The microstructural and electrochemical properties of these nanostructured Co 3 O 4 samples are thoroughly investigated. X-ray diffraction (XRD) analysis of all samples revealed prominent peaks corresponding to the (220), (311), (222), (400), (422), (511), and (440) planes, which are indicative of the Co 3 O 4 cubic structure with the space group Fd 3̄ m (227). Raman spectroscopy confirmed the presence of Co–O bonds and provided insights into the Functional groups of the samples. Scanning Electron Microscopy (SEM) was employed to examine the materials’ dimensions and surface architecture, revealing detailed features of the porous nanospheres. X-ray Photoelectron Spectroscopy (XPS) analysis verified the presence of Co 2+ and Co 3+ ions alongside O 2− in a spinel configuration, confirming the chemical state of the constituents. Brunauer–Emmett–Teller (BET) and Barrett–Joyner–Halenda (BJH) analyses showed characteristic of porous material. The electrochemical performance of the Co 3 O 4 porous nanospheres was evaluated in a 1M KOH aqueous electrolyte. The as-prepared samples exhibited a maximum capacitance of 309 F g −1 at a current density of 1 A g −1 , along with enhanced electrochemical stability, maintaining a significant proportion of their initial capacitance even after 2000 cycles.