The oxygen evolution reaction (OER) remains a major kinetic bottleneck in alkaline water electrolysis, requiring electrocatalysts that combine 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 summarizes recent advances in transition metal (TM)-based POMs integrated onto three-dimensional (3D) nickel foam (NF) supports (POM/NF) for the OER, including individually employed POM clusters, POM hybrids with diverse TM-based compounds such as layered double hydroxides, oxides, sulfides, and phosphides, as well as POM-based metal–organic frameworks. In these synergistic systems, TMs serve as the primary active sites, POMs enable charge delocalization and electronic modulation, and the NF scaffold offers a mechanically robust, highly conductive, and porous architecture that enables efficient charge transport. Thus, TM-based POM/NF electrocatalysts are discussed with emphasis on synthesis strategies, structural and interfacial engineering, and mechanistic insights. Key achievements include enhanced catalytic activity, improved durability in alkaline media, and stable operation at high current densities, while remaining challenges related to POM stability, synthesis reproducibility, and scale-up are critically discussed. Future perspectives highlight the concurrent optimization of robust POM chemistries and 3D NF architectures, where stable POM frameworks enable precise electronic modulation of the POM/NF materials while NF provides scalable, conductive, and mechanically resilient platforms. Then, the integration of POM/NF materials into practical OER devices, supported by advanced operando characterization and theoretical studies, is expected to guide the development of next-generation practical OER electrocatalysts.

The hydrogen evolution reaction (HER) in alkaline water electrolysis is fundamentally limited by the high energy barrier associated with water dissociation. Herein, we report the development of self-supported nitrogen-doped molybdenum carbide and vanadium oxide cluster heterostructures (N@Mo₂C/V₂O₃) on carbon fiber paper using organoimido-derivatized molybdovanadate nanoclusters as precursors. Experimental results and theoretical calculations demonstrate that the engineered cluster heterointerfaces significantly reduce the energy barrier of the rate-determining step, accelerating HER kinetics. Moreover, V₂O₃ acts as a cocatalyst that enhances hydrophilicity of the N@Mo₂C/V₂O₃ and, versus pristine N@Mo₂C, facilitates hydrogen desorption from the composite. The optimized N@Mo₂C/V₂O₃ cluster heterostructure exhibits exceptional electrocatalytic performance, delivering a current density of 300 mA·cm⁻² at an overpotential of merely 191 mV and maintaining stability over 400 h of continuous operation. When integrated into an alkaline water electrolyzer, the system requires only 1.94 V to achieve an industrially relevant current density of 500 mA·cm⁻², outperforming commercial platinum–carbon catalysts. These findings offer new perspectives and valuable insights into the development of efficient, stable, and economical noble metal-free electrocatalysts for green hydrogen production.

Ruthenium-containing polyoxometalates (Ru-POMs) are a class of heteropolyanions (vanadates, molybdates, or tungstates) containing at least one Ru atom as a heteroatom or “addenda” atom. In recent years, Ru-POMs have attracted considerable attention owing to their structural versatility, intriguing redox properties, and oxidation resistance, rendering them highly promising for applications in organocatalysis, electrocatalysis, photocatalysis, and beyond. This review summarizes the advances in Ru-POMs, covering their synthesis methods, structures, properties, and applications. It aims to serve as a reference and guide for the future design and development of novel Ru-POM structures and applications.

Large specific surface area (SSA) carbons have been demonstrated to be effective active materials and conductive substrates for energy storage devices, such as supercapacitors and batteries, due to their designable pore structures and buffering frameworks, as well as excellent electrical conductivity and chemical stability. Recently, tremendous efforts have been made in the design and preparation of large SSA carbons as electrode materials for energy storage devices, which can significantly enhance their capacitance, power and energy density, lifespan, and preeminent safety. In this review, recent advances in the development of large SSA carbons from structures and properties, porous carbon classifications, and preparation strategies to energy storage applications in supercapacitors, lithium-ion batteries, lithium-sulfur batteries, and zinc-air batteries are discussed. Finally, current challenges, future research directions, and prospects in the development of large SSA carbons for energy storage applications are highlighted.

Platinum (Pt)-based electrocatalysts remain the only practical cathode catalysts for proton exchange membrane water electrolysis (PEMWE), due to their excellent catalytic activity for acidic hydrogen evolution reaction (HER), but are greatly limited by their low reserves and high cost. Here, we report an interfacial engineering strategy to obtain a promising low-Pt loading catalyst with atomically Pt-doped molybdenum carbide quantum dots decorated on conductive porous carbon (Pt-MoC_x@C) for high-rate and stable HER in PEMWE. Benefiting from the strong interfacial interaction between Pt atoms and the ultra-small MoC_x quantum dots substrate, the Pt-MoC_x catalyst exhibits a high mass activity of 8.00 A·mg_Pt⁻¹, 5.6 times higher than that of commercial 20 wt.% Pt/C catalyst. Moreover, the strong interfacial coupling of Pt and MoC_x substrate greatly improves the HER stability of the Pt-MoC_x catalyst. Density functional theory studies further confirm the strong metal-support interaction on Pt-MoC_x, the critical role of MoC_x substrate in the stabilization of surface Pt atoms, as well as activation of MoC_x substrate by Pt atoms for improving HER durability and activity. The optimized Pt-MoC_x@C catalyst demonstrates > 2000 h stability under a water-splitting current of 1000 mA·cm⁻² when applied to the cathode of a PEM water electrolyzer, suggesting the potential for practical applications.