Hollow-structured ZIF-derived CoS₂/nitrogen doped carbon hybrid integrated with layered ReS₂Heterostructures as advanced Electrocatalysts for alkaline water splitting

The development of efficient and robust bifunctional electrocatalysts for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is crucial for cleaner hydrogen production. Herein, we report a sophisticated core-shell electrocatalyst by hydrothermal and calcination methods using metal-organic frameworks (MOFs) as precursors. The derivation of MOF features cobalt disulfide (CoS₂) as cores seamlessly integrated with a nitrogen-doped carbon matrix, which further supports an outer shell of rhenium disulfide (ReS₂) nanosheets (CoS₂-NC@ReS₂). Hollow core-shell architecture synergistically combines the high conductivity and stability of the N-doped carbon, the favorable catalytic activity of CoS₂ and ReS₂. Abundant heterointerfaces between CoS₂ and ReS₂ and tunable local charge distributions not only provide abundant surface active sites but also facilitate electrolyte penetration and release of generated H₂/O₂ bubbles. These synergistic effects significantly promote water dissociation and accelerate the electrocatalytic reaction kinetics. When evaluated for overall water splitting, the catalyst demonstrates exceptional bifunctional performance, requiring low overpotentials of 145 and 279 mV for both HER and OER to drive 10 mA cm⁻²with a total water-splitting voltage of 1.65 V. Furthermore, the robust core-shell structure endows the catalyst with remarkable long-term electrochemical stability and negligible performance decay. This work provides a viable MOF-derived strategy for constructing advanced heterostructured electrocatalysts for renewable energy applications.