SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4239-2
The sluggish kinetics of the oxygen evolution reaction (OER) remains a bottleneck for efficient water splitting. NiFe-layered double hydroxides (LDHs) are promising OER catalysts, but their performance is often limited by the high-spin state of Fe3+ and poor structural stability. Here, we report a series of amino acid-intercalated iron-rich NiFe-LDHs (AA-NiFe-LDHs) synthesized via a facile one-step coprecipitation method. Intercalation of glycine, alanine, and valine into the interlayer galleries expands the interlayer spacing and induces a partial transition of Fe3+ from high-spin to low-spin state, as confirmed by X-ray absorption spectroscopy and Mössbauer spectroscopy. The low-spin Fe3+ enhances the intrinsic catalytic activity by optimizing the adsorption energy of oxygen intermediates. Among the series, the glycine-intercalated sample (Gly-NiFe-LDH) exhibits the best OER performance in 1.0 M KOH, with an overpotential of 240 mV at 10 mA cm−2 and a Tafel slope of 38 mV dec−1, significantly outperforming the pristine NiFe-LDH (280 mV, 52 mV dec−1). Moreover, Gly-NiFe-LDH shows excellent long-term stability, retaining 95% of its initial activity after 24 h of chronopotentiometry at 10 mA cm−2. The intercalation also increases the electrochemically active surface area by 2.3-fold and reduces the charge transfer resistance from 12.5 Ω to 4.8 Ω. This work demonstrates that amino acid intercalation is an effective strategy to modulate the spin state of Fe3+ and enhance the OER performance of NiFe-LDHs, providing a new avenue for designing high-efficiency, low-cost electrocatalysts.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4359-0
Organic solar cells (OSCs) require cathode interlayers (CILs) that combine high charge transport, defect passivation, and thickness insensitivity for scalable manufacturing. Here, we report the synthesis of a novel A-D-A-A'-type polymer, PDPP2F-NDI-N, via the green and efficient direct arylation polymerization (DArP) method. The multiple electron-deficient units in the backbone confer strong electron-withdrawing character, effective work function modulation, enhanced built-in potential, high crystallinity, and ordered molecular packing. PDPP2F-NDI-N exhibits a high electron mobility of 1.01 × 10⁻³ cm² V⁻¹ s⁻¹ and electrical conductivity of 3.13 × 10⁻³ S m⁻¹, facilitating efficient charge extraction and transport. Its interfacial modification capability suppresses interfacial defects and reduces non-radiative recombination losses. In ternary OSCs, PDPP2F-NDI-N achieves a high power conversion efficiency (PCE) of 20.44%, with outstanding thickness insensitivity retaining 92.8% of peak PCE at a 30 nm CIL thickness, and a T80 lifetime exceeding 1700 hours under photo-thermal aging. This work demonstrates that poly(A-D-A-alt-A') backbone design combined with DArP synthesis provides an effective strategy for developing high-performance, thickness-insensitive, and stable polymeric CILs, advancing efficient, stable, and scalable OSC applications.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3900-8
Memristors, which leverage ion migration for resistance switching, offer breakthroughs in bionic perception, information security, and edge computing but face bottlenecks in functional integration and stability. Herein, we explore all-inorganic Cu3SbI6 nanocrystals (NCs) & PMMA composite memristors (Ag/PMMA&Cu3SbI6/ITO) regulated by NCs doping (0–15 wt%). The devices operate via electric field-induced Ag+ ion migration and conductive filament dynamics, where NCs act as local electric field enhancers. At a doping concentration of 4 wt%, stable bipolar switching (Ron/Roff > 2 × 10^3, cycling endurance > 700 cycles) enables the simulation of biological nociception/Pavlovian reflexes and the construction of basic logic gates. At 2 wt%, sparse NCs induce random filament formation for encryption key extraction, which integrates with 4 wt% logic gates to enable efficient encryption/decryption of text/image data. This work provides a strategy for designing multifunctional memristors by regulating ion transport through nanocrystal concentration, offering references for related functional integration and cross-disciplinary applications.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202510072
Porous structures are widely used in hydraulic and pneumatic systems for flow rectification and throttling, reducing velocity, regulating pressure, and improving flow stability. Numerical simulation is a common approach to study such flows, yet the lack of standardized parameter settings often leads to user-dependent errors. This study, based on the CFD software Fluent, systematically analyzes nine key parameters across three core stages: modeling, mesh generation, and solver settings. Under both quasi-2D and 3D configurations, the influence and underlying mechanisms of each parameter on simulation results are revealed, and a reference parameter-setting method is proposed. The method is validated against wind tunnel experiments, showing that the simulated average velocity reduction ratio γS deviates from experimental values by less than 6%, confirming its reliability and applicability. This work provides a basis for standardized parameter settings in numerical simulations of porous structures, enhancing consistency and predictive accuracy.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202607019
This study investigated the effects of biochar on volatile fatty acids (VFAs) production, biogas composition, physicochemical properties of the fermentation broth, and microbial community structure through batch anaerobic fermentation experiments using food waste as the substrate. The results demonstrated that the addition of biochar (1 g/L) significantly enhanced VFAs production, with the total VFAs concentration reaching 2150 mg/L in the biochar group, which was 30.2% higher than that of the control group (1651 mg/L). Acetic acid, propionic acid, and butyric acid were identified as the primary VFAs components. In the fermentation system, biochar exhibited a notable pH-buffering effect, stabilizing the fermentation environment. Additionally, its porous structure adsorbed ions during the fermentation process, resulting in a slightly lower electrical conductivity compared to the control group. Microbial community analysis revealed that biochar addition enriched key acidogenic bacteria, such as Defluviitoga and norank_f__Family_XI, optimizing the microbial community structure, and thereby facilitating organic acid production. In summary, biochar effectively promoted the efficient accumulation of VFAs during anaerobic fermentation of food waste by improving the fermentation microenvironment, enhancing system buffering capacity, and regulating microbial community composition. These findings provide theoretical support for sustainable enhancement of resource utilization of food waste.