Microstructural and electrochemical properties of Co₃O₄ porous nanospheres

Abstract

In this investigation, Co3O4 nanospheres are prepared at 200 °C using the combustion method and then annealed at 600 °C. Microstructural and electrochemical properties are measured in order to investigate nanostructured Co3O4 samples as prospective electrode materials. XRD spectra of all samples showed (220), (311), (222), (400), (422), (511), and (440) orientations, indicating Co3O4 in cubic structure with space group of Fd 3̄ m (227). Raman tests confirmed the existence of Co-O bonds and microstructure of the samples. Scanning Electron Microscopy examination demonstrates the materials' nanosphere-like form. XPS spectra demonstrate the existence of Co+2 and Co+3 with O-2 in a spinel configuration. The BET and BJH analyses demonstrate the type IV isotherm and the H3 hysteresis loop of as produced nanospheres of Co3O4. The electrochemical performance of Co3O4 nanospheres were examined in a 1M KOH aqueous electrolyte, and it was found that the as-prepared sample had the maximum capacitance of 209 Fg-1 at 1 Ag-1 current density as well as greater electrochemical stability even after 2000 cycles.