Synergistic Co-MOF/ZnS Composite: Advancing Supercapattery Performance and Catalyzing Hydrogen Evolution Reaction

Novel electrode development is crucial in the hunt for long-term energy storage options. In this work, we describe a promising advanced energy storage system with the fabrication of a cobalt metal organic framework doped with zinc sulfide (Co-MOF/ZnS) as an electrode and applied to energy storage and hydrogen evolution reaction (HER) applications. The Brunauer–Emmett–Teller (BET) method showed a 65.32 m2/g surface area for Co-MOF/ZnS. The Co-MOF/ZnS electrode has an outstanding capacity of 1615 C/g in a three-electrode setup. Furthermore, when paired with activated carbon (AC) in a supercapattery, this device exhibits a remarkable energy density of 59.33 W h/kg and a power density of 812 W/kg. The cycling stability of the Co-MOF/ZnS//AC supercapattery is evaluated by subjecting it to 10,000 cycles. The Co-MOF/ZnS//AC supercapattery test is carried out shortly after the stability test, and it retains 98% of its original capacity while maintaining a high Coulombic efficiency of 87%. In the HER test, Co-MOF/ZnS exhibits an outstanding overpotential of 434 mV.