Partial selenium surface modulation of metal organic framework assisted cobalt sulfide hollow spheres for high performance bifunctional oxygen electrocatalysis and rechargeable zinc-air batteries

There is still a significant technological barrier in the development of high-performance electrocatalysts with synergistic unreliable functions and morphological integrity that improves reversible electrochemical activity, electrical conductivity, and mass transport properties. Metal-organic compound networks are envisioned as a defect-rich porous framework that provides mesoporous hollow carbon nanostructures composed primarily of an in situ-grown N-doped graphitic carbon matrix and embedded selenium-doped CoS2 hollow spheres as efficient, highly reactive, and long-lasting chemical energy conversion functions of the system. This method enables hitherto inaccessible synthesis approaches to produce a highly porous conductive network at the microscopic level while exposing rich unsaturated reactive sites at the atomic level without losing electrical or structural integrity. Because of their inherent increased electrochemical surface area, and electron transfer, the porous framework, doping motifs, and tailored structural defects provide outstanding bifunctional oxygen electrocatalysts for both oxygen reduction reaction (ORR) and oxygen evolution reactions (OER). Moreover, using this selenium-doped MOF CoS2 hollow spheres electrode as an air-cathode, a rechargeable zinc-air battery with excellent discharge-charge performance and mechanical stability is successfully constructed. This study provides a feasible and universal technique for constructing diverse functional interconnected metal-organic coordinated compounds that may be employed for a wide variety of energy storage, conversion (e.g., fuel cells and metal-air batteries), and environmental applications.