SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4236-8
Electrochemical nitrate reduction (NO3RR) to ammonia offers a sustainable route for nitrogen recovery from wastewater, yet its efficiency is constrained by complex multi-step proton-electron transfers and competitive hydrogen evolution. Here, we report a series of binary cobalt-copper phosphates with precisely tuned Co/Cu ratios, revealing a volcano-type relationship between composition and catalytic activity. The optimized Co0.5Cu1.5(OH)PO4 catalyst, supported on a Ni3Co1OxHy/Ni foam substrate, achieves a Faradaic efficiency of 99.0% for ammonia at a high current density of 200 mA cm−2 in 1 M nitrate electrolyte, with a production rate of 9.18 mg h−1 cm−2 and sustained stability over 200 hours. In-situ ATR-FTIR spectroscopy and density functional theory calculations elucidate a tandem mechanism: Co sites promote water dissociation to generate active hydrogen (H*), while adjacent Cu sites facilitate nitrate adsorption and subsequent hydrogenation steps. This synergistic division of labor lowers the energy barrier for the rate-determining step, effectively suppressing HER and enhancing intrinsic kinetics. The work demonstrates that precise atomic-ratio engineering in dual-site transition metal phosphates provides a viable strategy to overcome activity-selectivity trade-offs in electrocatalytic nitrate-to-ammonia conversion.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4192-y
Electrochemical water splitting is pivotal for scalable green hydrogen production, yet its practical deployment hinges on cost-effective electrocatalysts with high activity and durability. This study introduces a low-cost, three-dimensional (3D) nanoporous ZrVFeCoNi material fabricated via chemical dealloying, at merely 0.16% of the cost of Pt. The structure-activity relationship between its microstructure and hydrogen evolution reaction (HER) performance was systematically explored. Lattice defect effects from multiphase intermetallic compounds, combined with multi-metal synergy, optimize H+ adsorption energy and electron transfer kinetics. The 3D nanoporous architecture provides a high electrochemical surface area with abundant active sites, enhancing electrolyte penetration and reducing interfacial mass transfer resistance. Consequently, the ZrVFeCoNi electrode exhibits outstanding HER performance, requiring only a 38 mV overpotential to reach 10 mA cm−2 and maintaining stable operation for 1000 h at 500 mA cm−2. Integrated into a full water electrolyzer (ZrVFeCoNi || IrO2/Ni), the system achieves a cell voltage of 1.60 V at a current density of 400 mA cm−2. Advanced characterization and density functional theory (DFT) calculations reveal that interfacial interactions and charge transfer at heterointerfaces drive catalytic activity, showcasing the potential of 3D nano-structured multiphase intermetallic compounds as high-performance electrocatalysts for green hydrogen systems.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3722-3
Magnesium alloys are promising biodegradable bone implant materials due to their biocompatibility and mechanical compatibility, but rapid degradation and postoperative bacterial infection limit clinical application. Here, zeolitic imidazolate framework-8 (ZIF-8) and 3,4,9,10-perylenetetracarboxylic diimide (PD) composite coatings (ZIF-8@PD) were fabricated in situ on micro-arc oxidation (MAO) coated AZ31 alloys via two-step and one-step (OS) methods. The MAO/ZIF-8@PD and MAO/ZIF-8@PD (OS) coatings reduced corrosion current density by three and two orders of magnitude, respectively, compared to MAO coating, due to the physical barrier of the 2D-co-3D MOF structure. Under 808 nm near-infrared laser irradiation, photothermal and photodynamic effects from PD, combined with contact killing by released Zn2+ ions, achieved bactericidal rates ≥99.5% against E. coli and S. aureus. Photothermal conversion efficiencies were 44.01% and 48.57% for the two-step and one-step coatings, respectively. The distinct Zn2+ sources led to different 2D-co-3D MOF structures, influencing degradation and antibacterial behavior. These coatings offer a strategy to enhance corrosion resistance and antibacterial activity of Mg alloys for biomedical applications.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3693-0
The development of catalysts with highly efficient oxygen evolution performance and low-Ir loading is key to scaling up the application of proton exchange membrane (PEM) water electrolysis technology. Here, an Ir-skin catalyst (Ir@KM) is realized on a potassium-manganese oxide (K0.25MnOx (KM)) using an ion-exchange method. The Ir-skin over the prepared Ir@KM has a low Ir–Ir atomic distance, endowing an energetically favorable oxide path mechanism to allow a low theoretical overpotential of 0.13 V. Ir@KM offers a low overpotential of ~280 mV at a current density of 10 mA cm−2 and provides a high mass activity of up to 18,500 A gIr−1 at a cell voltage of 1.8 V in PEM, which is 17.6 times higher than that of IrO2, demonstrating a significant advantage in reducing the cost of the membrane electrode. The presented Ir-skin concept represents a promising strategy to fabricate low-Ir catalyst with high activity and durability for practical applications of PEM.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4148-3
Biological ion channels exhibit multistate transport behavior beyond simple binary open-closed conformations, enabling dynamic control of neural signaling and transmembrane substance transport. Inspired by this, we synthesized a triphenylamine-ketone donor-acceptor (D-A) type poly(aryl amine-ketone) with multiple redox sites, allowing continuously tunable electrochemical states via hierarchical electron transfer. Combining this polymer with two-dimensional conductive MXene, we constructed a biomimetic nanofluidic transistor. Through side-group tuning to optimize redox matching, the polymer undergoes reversible conformation switching via intramolecular charge transfer at voltages below 1 V. The field-driven conformational changes induce electrostatic attraction, promoting reversible contraction of MXene interlayers. Synergistic coupling of interlayer spacing variation and dynamic interfacial charge rearrangement enables precise hierarchical control of ion flux. The device achieves three switchable ion transport states—closed, partially open, and fully open—with an ion switching ratio of 10 and outstanding cycling stability. Furthermore, synaptic plasticity features emulate fundamental attributes of biological signaling, providing a foundation for bioinspired neuromorphic devices.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202607012
This study investigated the effects of lychee wood biochar and lignin-degrading bacteria on compost maturity, substance transformation, and bacterial communities during the coupled process of aerobic composting and vermicomposting of cow dung and rice husk. Four treatments were established: no addition (CK), 5% (w/w) lychee wood biochar addition (T1), 0.5% (w/w) lignin-degrading bacteria (Bacillus subtilis, Aspergillus niger) addition (T2), and combined addition of 5% biochar and 0.5% bacteria (T3). Results showed that biochar and/or bacteria addition accelerated temperature rise, extended high-temperature duration to 13 days, and increased maximum temperature. Compared to CK, T1–T3 increased organic matter degradation by 3.97%–9.56%, humic acid content by 12.30%–24.09%, available phosphorus and potassium by 14.48%–32.50% and 6.97%–18.85%, respectively. NH3 emissions were reduced by 25.86%–34.26%, while nitrate nitrogen and total nitrogen increased by 12.83%–43.34% and 5.73%–13.18%, respectively. Seed germination index improved by 11.62%–29.20%. T3 exhibited the best overall performance. During aerobic composting, biochar and/or bacteria significantly increased relative abundances of Bacteroidota, Planctomycetota, and Acidobacteriota, but effects were not significant during vermicomposting. Functional genera such as Bacillus, Pseudomonas, and Chryseolinea were enriched in both stages. The study concludes that adding 5% lychee wood biochar and/or 0.5% lignin-degrading bacteria to cow dung and rice husk in coupled composting-vermicomposting improves bacterial community structure, promotes organic matter degradation, enhances humification, reduces nitrogen loss, and accelerates compost maturity, with combined addition being most effective.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202608019
The semi-dry desulfurization process in circulating fluidized beds (CFB) is sensitive to reactor flow field, which directly impacts desulfurization efficiency. To accommodate variable flue gas loads while maintaining constant Venturi tube velocity, a bypass structure crossing the Venturi section was introduced between the reactor inlet and diffusion section. Numerical simulations using ANSYS Fluent were conducted to evaluate the effects of bypass valve opening and number of bypass pipes on flow field uniformity and pressure loss. Results indicate that for flue gas load variations, bypass valve openings must exceed 50% and at least two bypass pipes are required to ensure uniform flow distribution. At 100% flue gas load, the empty reactor pressure loss was 911 Pa, decreasing to approximately 500 Pa at lower loads. The optimized bypass configuration enables stable and uniform flow fields with reduced pressure loss across a wide load range of 50%–100%, offering an effective solution for enhancing desulfurization efficiency and operational adaptability in industrial applications.