Electrochemical study of graphene oxide-integrated Co-MOF/trimetallic hydroxide nanostructures for next generation supercapacitor applications

Abstract

The integration of carbonaceous materials with metal–organic frameworks (MOFs) offers a synergistic interface that significantly enhances the electrochemical properties of electrode materials. In this work, we developed a composite electrode comprising graphene oxide (GO) and Co-based MOF (Co-MOF), further modified by the incorporation of a thin layer of transition metal hydroxides at the electrode–electrolyte interface to facilitate efficient charge transport. The resulting GO/Co-MOF/NiMnCu-OH (abbreviated as GO/Co-MOF/NiMnCu) nanocomposite was synthesized via a solvothermal method directly onto nickel foam (NF). This electrode exhibited a remarkable specific capacitance (C_s) of 2550.8 F g⁻¹ at a current density of 1 A g⁻¹, with excellent capacitance retention of 91% after 10 000 charge–discharge cycles at 20 A g⁻¹ in 3 M KOH electrolyte. Notably, the GO/Co-MOF/NiMnCu//GO asymmetric device demonstrated superior electrochemical performance, achieving a C_s of 1560.86 F g⁻¹ at 1 A g⁻¹. Furthermore, the device delivered an outstanding energy density of 137.28 W h kg⁻¹ and a high power density of 17 905.45 W kg⁻¹. These exceptional figures are attributed to the synergistic interaction among the large surface area of the GO nanosheets, the intrinsic porosity of Co-MOF, and the high electrical conductivity imparted by the transition metal hydroxides. Overall, the NF/GO/Co-MOF/NiMnCu nanocomposite represents a promising candidate for next-generation high-performance supercapacitor electrodes.