Synthesis and Electrochemical Performance of Co3S4@Zn0.5Co0.5Mn2O4 Nanocomposites and a Self-Powered Electrocatalytic System for Energy-Saving Hydrolysis

Herein, we report Co3S4@Zn0.5Co0.5Mn2O4 (CS-ZCMO) nanocomposites formed by etching a ZnCo metal–organic framework (ZnCo-ZIF) precursor to form the Zn0.5Co0.5Mn2O4 spinel structure and compositing it with Co3S4. This ZIF-derived nanosheet constitutes a reticular structure that enhances the interfacial contact with electrolyte ions and exhibits excellent electrochemical properties. With CS-ZCMO as electrode materials for a supercapacitor, the specific capacitance reached 3006 F/g at a current density of 1 A/g. The assembled CS-ZCMO//active carbon all-solid-state asymmetric supercapacitor (ASC) provided a specific capacitance of 212.3 F/g at a current density of 1 A/g and an energy density of 75.4 Wh/kg at a power density of 800 W/kg. Furthermore, the integrated circuits with ASCs demonstrated typical series and parallel connection characteristics. In addition, CS-ZCMO exhibited good electrochemical performance for energy-efficient hydrolysis, achieving a voltage of 1.324 V at 10 mA/cm2 in KOH + urea solutions. The self-powered electrocatalytic system was constructed using charged ASCs powered by a commercial solar panel and a hydrolysis electrolytic bath.