Interface Engineering Induced Homogeneous Isomeric Bimetallic of CoSe/NiSe₂ Electrocatalysts for High Performance Water/Seawater Splitting

Abstract

As a subclass of metal–organic frameworks (MOFs), zeolitic imidazolate frameworks (ZIFs) possess a highly ordered porous structure, extensive surface area, and accessible catalytically active sites, demonstrating significant potential in catalytic applications. Although the catalytic activity of individual ZIFs is relatively low, their pore structure and size distribution can be rationally designed and optimized through appropriate chemical modifications and post-treatment strategies to enhance their catalytic performance. This process requires meticulous control of ZIFs materials to meet the specific demands of catalytic reactions. In this study, a series of CoSe/NiSe₂ nanosheets is synthesized with precisely engineered morphology and architecture using a precursor route involving ZIFs. Notably, the CoSe/NiSe₂-3 nanosheets exhibit a remarkable overpotential of 250.5 mV at 10 mA cm⁻² in alkaline seawater and 215.3 mV at 10 mA cm⁻² in 1.0 m KOH electrolyte for the oxygen evolution reaction (OER). Furthermore, when used as a hydrogen evolution reaction (HER) catalyst, the material also shows excellent electrocatalytic activity. When integrated with the a forementioned electrocatalyst into a full cell configuration, the device operates at a low voltage of 1.956 V at a current density of 100 mA cm⁻² in an alkaline seawater medium, while maintaining excellent stability over a 12-h operational period.