Key Takeaways & Executive Findings
- •• • The optimized Mo2N-Ni catalyst achieves an overpotential of 19 mV at 10 mA cm−2, comparable to Pt/C, indicating near-Pt HER activity in alkaline media. • • The AEM electrolyzer delivers 500 mA cm−2 at 1.80 V, demonstrating high current capability suitable for industrial water electrolysis. • • The electrolyzer operates stably for 300 h, confirming long-term durability under continuous operation. • • The synthesis leverages electrostatic assembly of PMo12 and Ni(OH)2, preventing agglomeration and yielding 2D porous nanosheets, which enhances mass transfer and reduces impedance.
Abstract
NiMo-based catalysts are promising for the hydrogen evolution reaction (HER), yet optimizing their electronic structure and enhancing mass transfer remain challenging. Here, we report a route to synthesize two-dimensional (2D) porous Mo2N-Ni heterojunction nanosheets with tuned Ni/Mo ratio for enhanced alkaline HER. The precursor is assembled from polyoxometalate clusters (PMo12) and layered Ni(OH)2. The interaction between PMo12 and Ni(OH)2 suppresses particle agglomeration during pyrolysis, yielding 2D porous sheets composed of small Mo2N-Ni units. Electron transfer from Ni to Mo2N redistributes electrons at the heterojunction, optimizing intermediate adsorption/desorption. The porous structure enhances mass transfer, reducing catalyst impedance. The optimized catalyst exhibits an overpotential of 19 mV at 10 mA cm−2, comparable to commercial Pt/C. An anion exchange membrane (AEM) electrolyzer pairing this catalyst with NiFe-LDH achieves 500 mA cm−2 at 1.80 V and operates stably for 300 h. This assembly method offers a scalable strategy for efficient catalyst production.
1. Introduction
Alkaline water electrolysis is a key technology for green hydrogen production, but its efficiency is hampered by the sluggish kinetics of the hydrogen evolution reaction (HER) on non-noble metal catalysts. Platinum-based catalysts offer near-optimal hydrogen adsorption free energy, yet their high cost and scarcity limit widespread deployment. NiMo-based materials have emerged as promising alternatives due to the 'd-electron complementary' effect, which tunes the d-band center toward the Fermi level, enhancing HER activity. However, conventional synthesis routes often yield agglomerated particles with limited active surface area and poor mass transport, restricting performance.
This work addresses these bottlenecks by employing polyoxometalate (PMo12) clusters as both molybdenum source and structural modifier. Electrostatic assembly with Ni(OH)2 nanosheets prevents severe agglomeration during pyrolysis, yielding porous two-dimensional heterojunction nanosheets of Mo2N and Ni. The intimate contact between Mo2N and Ni induces electron transfer, optimizing the electronic structure for HER. The porous architecture facilitates electrolyte penetration and gas bubble release, reducing charge transfer resistance. This synergistic design achieves overpotentials comparable to Pt/C and enables stable operation in an AEM electrolyzer at industrially relevant current densities.
Loading authentic research manuscript (Pages 1–5)...
Xianyun Yue, Dongxu Wang, Chengxu Jin, Kuo Lin, Yuying Fan, Haixin Zhu, Zexu Fang, Aiping Wu, Chungui Tian (2026). Suppressing the aggregation and optimizing the electronic structure of porous Ni nanosheets by POMs-derived Mo2N for efficient hydrogen evolution in AEM water electrolysis. SCIENCE CHINA Materials. https://doi.org/10.1007/s40843-025-3685-7
Research & Educational Purpose Only: The translations, structured abstracts, analytical annotations, and data reports provided by SinoGreenTechare intended exclusively for academic research, internal corporate R&D, and educational benchmarking. They do not constitute formal engineering, chemical safety, legal, or professional advice.
Copyright & Intellectual Property Notice: Original copyright of the underlying source articles and experimental data remains with the respective authors, institutions, and original publishing journals. SinoGreenTech claims intellectual property only over its proprietary translations, analytical syntheses, and AEO structured enhancements in accordance with international fair use and academic citation principles.
Frequently Asked Questions
What is the specific role of PMo12 in preventing particle agglomeration during pyrolysis?
PMo12 clusters interact with Ni(OH)2 layers, likely via electrostatic forces and hydrogen bonding, which spatially separates Ni species and restricts their migration and coalescence during thermal treatment. This results in the formation of small Mo2N-Ni units that assemble into porous nanosheets, preserving high surface area and active sites.
How does the electron transfer between Ni and Mo2N affect the HER mechanism?
Electron transfer from Ni to Mo2N enriches the electron density on Mo2N, which optimizes the adsorption energy of hydrogen intermediates (H*) and water dissociation. This balances the Volmer and Heyrovsky/Tafel steps, lowering the activation barrier and improving the intrinsic activity.
What is the long-term stability of the catalyst under industrial operating conditions?
The AEM electrolyzer with Mo2N-Ni cathode and NiFe-LDH anode operates at 500 mA cm−2 for 300 h without significant degradation, indicating robust mechanical and chemical stability. The porous structure and heterojunction integrity are maintained, as confirmed by post-mortem analyses.
How does the porous 2D structure contribute to mass transport and impedance reduction?
The 2D porous morphology shortens ion diffusion pathways and facilitates electrolyte penetration, while the interconnected pores allow efficient release of gas bubbles, reducing bubble-induced resistance. This lowers the charge transfer resistance and improves the overall electrode kinetics, as evidenced by the low overpotential.
What is the scalability potential of this synthesis method for industrial catalyst production?
The assembly method is simple and solution-based, using readily available precursors (PMo12 and Ni(OH)2). It avoids complex equipment and harsh conditions, making it amenable to scale-up. The resulting catalyst's high performance and stability suggest it could be integrated into commercial AEM electrolyzers, though further optimization of catalyst loading and electrode fabrication is needed.
Related Chinese Research & Cross-Citations
Ammonium Vanadate Cathodes in Aqueous Zinc-Ion Batteries: Design Strategies and Research Progress
Aqueous zinc-ion batteries (AZIBs) offer a compelling combination of high safety, environmental compatibility, and abundant zinc resources, positioning them as viable candidates for grid-scale energy storage. Their practical deployment, however, is constrained by cathode materials that suffer from structural degradation, sluggish Zn2+ diffusion, and inadequate electronic conductivity. Ammonium vanadates (AVOs) have emerged as high-performance cathodes owing to their layered or tunneled frameworks, which accommodate reversible Zn2+ (de)intercalation with diffusion coefficients superior to conventional vanadium oxides. This review systematically examines recent advances in AVO cathodes for AZIBs, correlating morphological variations—including nanowires, nanobelts, and microflowers—with electrochemical characteristics. The analysis establishes structure–performance relationships that govern capacity retention, rate capability, and cycling stability. Key optimization strategies are critically assessed: defect engineering to enhance electronic conductivity and active site density, interlayer spacing modulation via pre-intercalated cations or structural water to facilitate Zn2+ transport, and composite construction with conductive carbonaceous or polymeric matrices to mitigate dissolution and improve mechanical integrity. Despite these advances, challenges persist in achieving long-term cycling stability (>10,000 cycles) and high areal mass loading (>10 mg cm-2) required for commercial viability. The review concludes by outlining future research directions, including operando characterization of degradation mechanisms and scalable synthesis routes for AVO cathodes in practical AZIB configurations.
Microenvironment-responsive therapeutic platforms: Innovations for spinal cord injury repair
Spinal cord injury (SCI) remains a formidable clinical challenge due to the complex, dynamic lesion microenvironment that impedes axonal regeneration and functional recovery. This highlight examines a microenvironment-responsive therapeutic platform integrating microneedle delivery, ferroptosis modulation, and hydrogen therapy. The platform leverages the pathological hallmarks of SCI—oxidative stress, iron dyshomeostasis, and lipid peroxidation—to achieve spatiotemporally controlled cargo release. By combining microneedle arrays for minimally invasive intraparenchymal administration with hydrogen-releasing biomaterials, the system addresses the dual bottlenecks of poor drug penetration across the blood-spinal cord barrier and insufficient neutralization of reactive oxygen species. Ferroptosis inhibition is achieved through iron chelation and glutathione peroxidase 4 (GPX4) stabilization, while hydrogen gas scavenges hydroxyl radicals and peroxynitrite. This multimodal strategy attenuates secondary injury cascades, reduces glial scar formation, and promotes neural stem cell differentiation. The work is supported by the National Natural Science Foundation of China (82574518) and the Talent Cultivation Project of Paring Academicians with Young Talents in higher education institutions in Zhejiang. The authors declare no conflict of interest. This highlight underscores the translational potential of microenvironment-responsive platforms for SCI repair, emphasizing the need for rigorous preclinical validation and scalable manufacturing.
Dual-Site Adsorption over Phosphorus-Doped Copper Oxide for Efficient CO2 Electroreduction to Ethylene
Electroreduction of CO2 to ethylene offers a promising route for renewable electricity storage, yet achieving high ethylene selectivity at industrial current densities remains challenging due to the large energy barrier for C–C coupling. Here, we report a “MOF-assisted in situ doping” strategy to introduce the oxophilic nonmetal phosphorus (P) into the copper oxide (CuO) lattice, constructing a localized Cu–P dual-site adsorption configuration for the key *OCCHO intermediate. The optimized catalyst delivers an impressive Faradaic efficiency of 64.6% for ethylene with a partial current density of 646 mA cm-2. Comprehensive structural characterizations demonstrate that P mainly occupies Cu sites, generating abundant lattice defects and oxygen vacancies. In situ synchrotron infrared spectroscopy and theoretical calculations reveal that P doping modulates the electronic structure of Cu, optimizes the binding energies of *CO and *CHO, and stabilizes *OCCHO via P–O/Cu–C dual-site adsorption, thereby significantly lowering the asymmetric C-C coupling energy barrier to 0.74 eV. This work highlights a dual-site microenvironment regulation strategy for CO2-to-ethylene electroreduction.
Hydrophilic Single-Atom Interface Unlocks Low-Potential CO Removal on Pt in PEMFCs
Proton exchange membrane fuel cells (PEMFCs) fed with reformate hydrogen suffer severe anode poisoning by trace CO, necessitating high CO electrooxidation potentials that degrade performance and durability. This work introduces a Pt@CrSA-N-C anode catalyst featuring a hydrophilic Cr single-atom interface that simultaneously weakens CO adsorption on Pt via electronic regulation and promotes water activation, thereby lowering the CO oxidation onset potential to approximately 0.13 V vs. RHE. The onset potential was determined by two independent methods: the first potential at which the background-corrected current exceeds 0 mA cm-2 during CO oxidation reaction tests in a three-electrode system, and the potential at which the forward scan current exceeds the N2 background current in CO-stripping voltammetry. The catalyst achieves a maximum power density under 100 ppm CO that surpasses reported advanced catalysts, as compiled in Table S5. Structural, spectroscopic, and electrochemical characterizations collectively establish a coherent rationale for the hydrophilic single-atom interface strategy. This approach addresses the longstanding trade-off between CO tolerance and Pt utilization, offering a viable route for low-potential CO removal in practical PEMFC anodes.
An Ionoelastomer-Based Bioinspired Wearable Electronics with Tele-Perception and Tactile Sensation for Machine Learning-Assisted Rehabilitation Management
Comprehensive assessment of rehabilitation efficiency is essential for designing appropriate training programs for better musculoskeletal functional recovery. Existing contact-receptor-dependent rehabilitation assessment systems mostly focus on assessing the restoration of muscle function by evaluating grip strength or joint flexion angle; however, parameters reflecting neuromuscular synergistic function are always overlooked. Herein, we develop an ionoelastomer-based soft artificial electroreceptor (SAER) that integrates tele-perception and tactile sensation to track the rehabilitation process, collecting signals related to approaching speed and grip strength sequentially. The SAER uses polyurethane ionoelastomer incorporated with quasi-solid conductive salt as the electric field receptor, and is integrated on a rehabilitation-training ball after assembly to establish an untethered detection device; this enables the remote capture of hand approaching parameter within a 9 cm range, followed by the quantification of grip strength when contacting and grasping. Furthermore, a data-driven assessment system is established by integrating machine learning, which accurately classifies rehabilitation efficiency into six levels; it supports for rehabilitation evaluation and training programs adjustment. Overall, the SAER-based rehabilitation management system establishes a paradigm that synergistically evaluating parameters corresponding to neuromuscular functional restoration and holds strong potential for home-based active rehabilitation for minimizing dependence on frequent clinical supervision.
Microwave-Absorbing Materials with Strong Environmental Adaptability for Corrosion Protection, Anti-Icing, and Thermal Management
Microwave-absorbing materials (MAMs) deployed on naval vessels, aerospace vehicles, and critical electronic systems face coupled electromagnetic, marine salt-spray corrosion, and extreme-temperature loads that legacy single-function absorbers cannot withstand. This review consolidates progress on three environmentally adaptive MAM classes: corrosion-protective, anti-icing, and thermal-management absorbers. The electromagnetic loss and impedance-matching fundamentals are first established, then the synergistic mechanisms, design strategies, and characterization protocols for each class are examined against representative material systems and their measured performance. The analysis identifies a shared design logic—multiscale hierarchical architecture, interfacial polarization engineering, and multifunctional phase integration—while distinguishing the divergent protection mechanisms: barrier and passivation effects for corrosion, surface-energy and latent-heat regulation for anti-icing, and phonon–electron transport decoupling for thermal management. Persistent bottlenecks include the trade-off between impedance matching and protective-layer density, the absence of standardized coupled-field test protocols, and the scarcity of long-term salt-spray and thermal-cycling durability data. Future directions are delineated: intelligent self-adaptive absorbers, multiphysics-coupled simulation frameworks, and environmentally benign multifunctional integration. The review provides a theoretical and technical basis for the design, construction, and engineering scale-up of next-generation high-performance absorbers for aerospace, electronic, and marine equipment.