Polyoxometalate electrocatalysts supported on nickel foam for enhanced oxygen evolution in alkaline media

The oxygen evolution reaction (OER) remains a major kinetic impediment in alkaline water electrolysis, requiring electrocatalysts that deliver high activity, durability, and scalability at industrially relevant current densities. Polyoxometalates (POMs), owing to their well-defined metal–oxo architectures and rich redox chemistry, have emerged as versatile electronic modulators and functional building blocks for OER catalysis. This review spans recent advances in transition metal (TM)- based POM integrated on three-dimensional (3D) nickel foam NF (POM/NF) electrocatalysts for OER, including POM clusters used individually, POM hybrids with diverse TM-compounds including layered double hydroxides, oxides, sulfides, and phosphides, as well as polyoxometalate-based metal–organic frameworks (POM-MOFs). In these synergistic systems, transition metals serve as primary active sites, POMs enable charge delocalization and electronic tuning, and the NF scaffold offers a mechanically robust, highly conductive, and porous architecture that supports efficient charge transport. Thus, TM-based POM/NF electrocatalysts are discussed by covering synthesis strategies, structural and interfacial engineering, and mechanistic insights. Key achievements include enhanced activity, improved alkaline durability, and stable operation at high current densities, while remaining challenges in POM stability, reproducibility, and scale-up are critically discussed. Future perspectives emphasize the concurrent optimization of robust POM chemistries and 3D NF architectures, where stable POM frameworks enable precise electronic modulation while NF provides scalable, conductive, and mechanically resilient platforms. Then practical OER device integration by these POM/NF materials using advanced operando characterization and theoretical studies will guide the development of practical OER electrocatalysts.