Metal-organic framework derived porous nanosheets-like Co3O4 electrodes on stainless steel with high-performance for supercapacitors

Abstract

In this work, three-dimensional (3D) nanoporous MOF-derived Co3O4 was successfully prepared by a facile, easy, and rapid solvothermal method on a stainless steel substrate using 1, 4-BDC organic linker and a precursor. Additionally, the effects of the Co-precursor and organic linker on the structure, composition, and morphology of the prepared MOF-derived Co3O4 samples were investigated through an XRD study, which indicated that the MOF-derived Co3O4 thin films exhibited crystalline nature upon deposition on the stainless steel substrate. FE-SEM revealed a porous nanosheet-like morphology. EDAX analysis confirmed the formation of the MOF-derived Co3O4 structure, indicating the presence of cobalt, oxygen, and carbon elements. The oxidation states of the prepared MOF-derived Co3O4 thin films were determined by X-ray photoelectron spectroscopy. Furthermore, the electrochemical performance of the MOF-derived Co3O4 samples was evaluated in a three-electrode system using 1 M KOH electrolyte. Consequently, optimized MOF-derived Co3O4 exhibited excellent electrochemical performance attributed to these advantages. The C3 sample demonstrated an outstanding specific capacitance of 1210 F/g at a current density of 0.5 mA/cm², along with remarkable cyclic stability retention of 94.30 % after 4000 charging/discharging cycles. Additionally, the MOF-derived Co3O4 (C3) electrode showed an excellent energy density of 35.70 Wh/kg and a power density of 4.5 kW/kg. As a result, the unique hierarchical porous structure of MOF-derived Co3O4 also offers effective pathways and excellent electrochemical performance, making it a promising candidate for advanced electrode materials in high-performance supercapacitors.