SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4406-y
Covalent organic frameworks (COFs) are promising adsorbents for uranium extraction from complex aqueous environments due to their tunable pore structures and customizable functionalities. However, conventional bottom-up assembly routes yield frameworks with fixed dimensionality, where internal pores and buried functional sites remain inaccessible, limiting dynamic optimization for uranium capture. This study introduces a reversible coordination-directed clip-off strategy that enables dimensional programming of COFs through silver-nitrogen coordination bonds and thiosulfate/silver ion regulators. The approach allows controlled cleavage and reconstruction of coordination bonds, dynamically exposing hidden binding sites and adapting the framework to uranium extraction requirements. While the strategy demonstrates high-efficiency uranium extraction, it faces challenges including increased material and operating costs from silver-based regulators, potential structural fatigue from repeated cleavage-reconstruction cycles, and limited validation beyond laboratory scale. The reversible dimensional programming is generalizable to other reticular frameworks such as metal-organic frameworks (MOFs), enabling stimuli-responsive smart materials, controlled-release carriers, and adaptive separation membranes. Integration with machine learning and computational screening could accelerate rational design of functional active sites. This interdisciplinary approach offers a pathway toward intelligent, dimensionally morphing materials for energy and environmental sustainability, though optimization of regulating components and structural durability is required for practical scalability.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4176-y
Three-photon microscopy (3PM) in the near-infrared-III (NIR-III) window (1600–1840 nm) enables high-resolution visualization of cerebral vasculature in vivo, but its imaging depth and quality are limited by the performance of fluorescent probes. Here, we report a probe optimization strategy transitioning from mirror symmetry to centrosymmetry, yielding a highly symmetric aggregation-induced emission (AIE) molecule, T4PQ. The centrosymmetric structure aligns donor-acceptor units, promoting uniform electron cloud delocalization and directional charge transfer, which enhances exciton formation and suppresses non-radiative decay, thereby increasing fluorescence quantum yield. This symmetry also boosts the three-photon absorption cross-section by enhancing electron delocalization and transition dipole moment, enabling stronger nonlinear optical responses under long-wavelength excitation. T4PQ nanoparticles (T4PQ NPs) exhibit an enhanced three-photon absorption cross-section, high fluorescence quantum yield, and excellent photostability. In murine models, T4PQ NPs achieved three-dimensional cerebrovascular imaging at a depth of 1785 μm and real-time hemodynamic observation in microvessels at 1006 μm depth, with good biocompatibility. These results validate the advantage of centrosymmetric molecular design for deep-brain imaging probes, offering a high-performance tool for neurovascular research.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3700-7
Photocatalytic synthesis has been considered a promising technology for solar-to-chemicals conversion. Here, a series of novel photocatalysts was synthesized by decorating uranyl sites on imine-based covalent organic frameworks (i-COF) and proved functioning for the uniformly boosted H2O2 production by 1.6–10.1 folds compared with the bare i-COFs in a wide pH range from 2 to 11. Typically, an optimal H2O2 production rate of 1435.9 μmol g−1 h−1, i.e., 28.72 mmol g(U)−1 h−1, was realized over uranyl decorated TTa-COFs under visible light. Systematic investigations reveal that the universally and remarkably promoted performance is attributed to the outstanding electron-transfer ability, accelerated activation of molecular oxygen and favored formation of ·O2− and *OOH as the key intermediate by virtue of the decorated uranyl ions; thus the two-step single-electron oxygen reduction reaction (ORR) for H2O2 photo-generation is significantly facilitated. This work paves a new way for the uranyl-decorated COFs as a novel photocatalyst and provides in-depth insight to the reaction mechanism for photocatalytic H2O2 production.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3831-0
Ammonia decomposition is a key process for generating COx-free hydrogen, yet conventional cobalt catalysts require high temperatures (>550 °C) to overcome the strong Co–N binding that limits N2 desorption. Here we report a novel Co catalyst supported on a Ce and N co-modified perovskite (Co@La_xCe_{1-x}AlO_{3-y}N_z) that achieves 92.6% ammonia conversion with a hydrogen production rate of 9.7 mmol g−1 min−1 at 425 °C and GHSV = 9000 mL h−1 g_cat−1, representing a 125 °C reduction in operating temperature relative to conventional Co-based catalysts. Mechanistic studies using isotopic labeling and in-situ DRIFTS reveal that synergistic Ce and N modification creates a unique LA-L(A+B)-LB active site configuration, which lowers the Schottky barrier at the metal-support interface and promotes facile hydrogen spillover. The reaction proceeds via an interfacial Mars-van Krevelen mechanism, contrasting with the traditional Langmuir-Hinshelwood pathway on conventional Co catalysts. This work provides new insights for designing low-temperature Co-based ammonia decomposition catalysts.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3755-8
Lead-free piezoelectric ceramics, including potassium sodium niobate (KNN), bismuth sodium titanate (BNT), and barium titanate, are promising alternatives to lead-based counterparts due to environmental regulations. However, their functional properties—piezoelectric coefficient, mechanical quality factor, dielectric loss, Curie temperature, and thermal stability—remain inferior. Oxygen vacancy engineering has emerged as a key strategy to optimize these properties via defect modulation. Oxygen vacancies, prevalent point defects, arise from high-temperature processing, non-stoichiometry, volatile oxide evaporation, or reducing atmospheres. Acceptor doping and post-processing annealing further increase their concentration. These defects influence electrical conduction, piezoelectric/dielectric behavior, and catalytic activity. They exist as lattice vacancies, domain wall vacancies, grain boundary vacancies, and defect dipoles with cation vacancies. Their presence induces lattice distortion, hinders domain wall motion, increases coercive field, and enhances mechanical quality factor via hardening. Defect dipoles align with spontaneous polarization, creating internal bias fields that pin domains, reducing losses. Quantification of oxygen vacancies remains challenging; concentrations below 1 at% in NBT and KNN are difficult to detect. Techniques like XPS have reliability issues. A combination of impedance spectroscopy, XPS/STEM, EPR/PAS is recommended. Defect chemistry modeling, using acceptor doping to fill vacancies, allows inference of non-stoichiometry ranges. For NBT, Bi deficiency of 0.0017–0.0033 and O deficiency of 0.0025–0.0050 were calculated, corresponding to Na0.5Bi0.4967–0.4983TiO3.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3919-0
Nuclear energy is critical for sustainable economic development and achieving carbon neutrality. With only about 6.14 million tons of terrestrial uranium, sufficient for ~70 years of global nuclear power plant operation, the recovery of uranium from seawater and spent fuel is essential for long-term nuclear fuel supply. The ocean contains approximately 4.5 billion tons of uranium, which could sustain nuclear power for ~2000 years if efficiently extracted. However, seawater uranium extraction faces significant challenges due to the extremely low uranium concentration (~3.3 ppb), high concentrations of competing ions, natural organic matter, and marine biofouling. This perspective reviews representative laboratory advances, including sulfonated covalent organic frameworks (S-COF) achieving a sorption capacity of 31.5 mg/(g·day) with high selectivity, amidoxime-based organic cages with a capacity of 11.97 mg/g over 30 days, and a micro-redox reactor strategy that continuously regenerates binding sites. Electrochemical methods have also shown promise for converting soluble U(VI) to insoluble U(IV) oxides. Despite these advances, the transition from laboratory powders to durable marine materials remains problematic. Key gaps include the need for antibacterial properties, mechanical stability under wave action, cost competitiveness with terrestrial mining, and environmental safety of nanomaterials. Artificial intelligence (AI) is proposed to accelerate the design of high-performance, stable materials. This perspective emphasizes the necessity for interdisciplinary research to bridge the gap between bench-scale innovations and practical ocean deployment.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3788-9
Fabrication of large-area perovskite solar modules under ambient air conditions remains a critical challenge due to air sensitivity of perovskite intermediate phases during crystallization. Here, we introduce 2-iodoimidazole (IIZ) into the perovskite precursor, enabling the formation of an air-stable pure δ-phase intermediate, which, upon annealing, fully transforms into a highly oriented α-phase perovskite film with reduced defects and variability. Leveraging this approach, we achieve a stabilized power conversion efficiency of 20.9% for 927.5 cm2 perovskite solar modules with high reproducibility. The encapsulated modules meet stringent international photovoltaic testing standards (IEC61215:2021), demonstrating excellent stability under continuous operation, thermal cycling (−40 to 85 °C) and damp heat (85 °C and 85% relative humidity).
New Carbon Materials•2026•DOI: 10.1016/S1872-5805(26)61117-1
Graphite-based bipolar plates (GBPs) are critical components in proton exchange membrane fuel cells (PEMFCs), offering excellent electrical and thermal conductivity, corrosion resistance, and durability. However, their inherent brittleness and porous structure lead to inadequate mechanical strength and high gas permeability, limiting practical application and large-scale manufacture. This review summarizes recent advances in GBP fabrication, focusing on the effects of graphite raw materials, polymer matrices, conductive and reinforcing fillers, and molding processes on GBP performance. The relationships among graphite particle size, morphology, surface characteristics, filler dispersion, interfacial bonding, resin content, and the electrical conductivity, mechanical strength, gas permeability, and corrosion resistance of GBPs are discussed. The effects of material composition, microstructure, and processing conditions on overall performance are analyzed. Trade-offs between electrical conductivity, mechanical strength, gas permeability, corrosion resistance, and processability are highlighted. Strategies for improving performance are summarized, including optimization of graphite raw materials, multiscale filler design, interfacial regulation, resin-content optimization, and improvements in molding processes.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025021805
This study analyzed 75 precipitation samples collected from August 2017 to August 2018 in the Meili Snow Mountain region of the Hengduan Mountains. The chemical characteristics of inorganic ions and their seasonal variations between monsoon and non-monsoon periods were examined. The volume-weighted mean total ion concentration was 246.2 μeq·L–1, with higher concentrations in the non-monsoon season and lower in the monsoon season. The dominant water chemistry type was HCO3–-Ca2+. Principal component and partial correlation analyses indicated that Ca2+, Mg2+, HCO3–, and SO42– mainly originated from local sedimentary rock dust, while Na+ and Cl– were primarily marine during the monsoon, with reduced marine influence in the non-monsoon period. NO3– was largely attributed to South Asian pollution emissions, with significant contributions from biomass burning to K+, Na+, and Cl– in the pre-monsoon phase. PMF source apportionment confirmed that during the monsoon, approximately 70% of Cl– and Na+ were from sea salt, whereas in the non-monsoon, over half came from biomass burning. NO3– was almost entirely from fossil fuel combustion during the monsoon (96%), decreasing to 72% in the non-monsoon. Ca2+ and Mg2+ were mainly from carbonate dust in the monsoon and weathered dust in the non-monsoon. Backward trajectory analysis showed that the non-monsoon period was dominated by westerly transport (60%), while the monsoon was dominated by southwest monsoon transport (81%). These findings provide scientific basis for understanding atmospheric pollution and background values in the region.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202502081
Coal dust from open-pit mining severely impacts the mining area and surrounding environment, exhibiting significant dynamic changes. However, quantitative assessments of the pollution extent and multi-timescale evolution remain insufficient. Based on the Google Earth Engine platform and Landsat TM/ETM+/OLI/OLI-2 and Sentinel-2 MSI imagery from 2001 to 2024, we retrieved the enhanced coal dust index (ECDI) and coal dust pollution levels. Combined with the mine lifecycle stages, we revealed the temporal and spatial variations of coal dust in the Baorixile mining area. Annual and monthly remote sensing retrievals were stacked to construct multi-year and intra-annual dust impact frequency (DIF) indicators, precisely quantifying the spatial extent and frequency of coal dust pollution. Results show that from 2001 to 2024, the interannual coal dust pollution experienced three stages: fluctuating increase, significant decrease, and stabilization. The average pollution degree peaked at 0.41 in 2010 and remained between 0.18 and 0.22 from 2016 to 2024. The spatial pattern improved, converging from widespread diffusion to the open-pit and bare coal accumulation areas. From 2019 to 2023, intra-annual pollution increased then decreased, with summer most severe, followed by autumn, spring, and winter. Based on annual retrievals, 6 periods of multi-year DIF (2001-2024) were generated at 4-year intervals. The maximum impact range (DIF≥1) first expanded then contracted significantly; the perennial impact area (DIF=4) shifted from the southeast to the central-western open-pit, indicating a notable migration of dust disturbance gravity and effective control. Based on monthly retrievals, 6 periods of intra-annual DIF (2019-2024) were generated at 12-month intervals. The intra-annual DIF showed a gradient decreasing from the core operation area to the periphery. High-frequency zones (DIF≥9) were stably concentrated in the open-pit. The affected area fluctuated downward from 88.14 km² in 2019 to 72.84 km² in 2024. This study provides theoretical and data support for scientifically understanding and monitoring the ecological status of mining areas and formulating dust suppression measures.
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.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3923-x
Perovskite solar cells (PSCs) have achieved certified efficiencies exceeding 27%, rivaling silicon-based technologies, yet their operational stability under real-world conditions remains a critical barrier to commercialization. Exposure to full-spectrum sunlight, particularly ultraviolet (UV) radiation, coupled with diurnal temperature fluctuations and ingress of moisture and oxygen, induces multi-mode degradation pathways, including lattice distortion, defect accumulation, and interfacial strain. Conventional stabilization strategies typically address single degradation routes and rely on static passivation or fixed strain compensation, failing to adapt to the dynamic stress fields arising from thermal expansion-contraction cycles at buried interfaces. Here, we highlight a recent breakthrough by Zhou et al. that introduces a stepwise conformational engineering strategy to design multifunctional molecules capable of simultaneous UV shielding, dynamic strain regulation, and defect passivation. Starting from 1,1-diphenylethylene (DPE), which exhibits intrinsic UV absorption, a flexible octyl alkyl chain is incorporated to yield 1-octyl-2-(1-phenylvinyl)benzene (OPVB). The conformational freedom of the alkyl chain enables reversible thermal expansion and contraction, allowing in situ modulation of interfacial stress. Further functionalization with hydroxyl and carbonyl groups produces diethylamino hydroxybenzoyl hexyl benzoate (DHHB), which integrates all three targeted properties. This molecular design addresses the bottleneck of multi-mode degradation by providing dynamic stress management, UV protection, and defect healing, thereby enhancing device stability and performance. The work establishes a new paradigm for fabricating stable PSCs under realistic operating conditions, with implications for accelerating industrial deployment.
Journal of Fuel Chemistry and Technology•2026•DOI: 10.1016/S1872-5813(26)60677-9
Mg-, Ca-, Sr-, and Ba-single-doped La2O3 as well as Mg-Ba co-doped La2O3 catalysts were synthesized via a hydrothermal method and evaluated for the oxidative coupling of methane (OCM). The experimental results revealed that the Mg-modified La2O3 catalyst activates O2 and CH4 effectively, yet achieves only moderate C2+ selectivity. Conversely, the Ba-modified analogue affords high C2+ selectivity, albeit at the expense of lower reaction activity. Notably, the Mg-Ba co-doped La2O3 catalyst strikes an effective balance between activity and selectivity, enhancing catalytic performance while maintaining a high C2+ selectivity. Specifically, at a Mg/Ba molar ratio of 1:1 and 700 °C, it achieved a CH4 conversion of 29.5%, a C2+ selectivity of 54.5% and a corresponding C2+ yield of 16.1%. The characterization results indicate that Mg and Ba co-doped La2O3 catalysts promote the formation of more superoxide (O2−) species on the catalyst surface, which in turn significantly enhances both the activity and selectivity of La2O3 catalysts. In situ DRIFTS revealed the presence of superoxide species on the surface of both Mg- and Ba-doped catalysts, with the co-doped system exhibiting a significantly more intense signal for the superoxide species. O2/H2-TPR studies revealed that Mg and Ba co-doped La2O3 catalysts exhibit superior O2 activation capabilities compared to those doped with Mg or Ba alone. CH4/O2 pulse experiments revealed that the co-doped catalysts facilitate faster establishment of oxygen adsorption equilibrium, thereby enhancing CH4 activation and the subsequent formation of C2 products. This work establishes that co-doping La2O3 with Mg and Ba represents an effective strategy for improving catalytic performance in OCM, primarily by modulating the generation and stabilization of key active oxygen species.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4104-4
Covalent organic frameworks (COFs) are promising adsorbents for gas adsorption and separation, yet identifying optimal structures among their vast design space requires efficient high-throughput screening. Conventional machine-learning predictors rely heavily on specific gas-related features, which are time-consuming and limit scalability, leading to inefficiency and labor-intensive processes. Here, we propose COFAP, a universal COFs adsorption prediction framework that extracts multi-modal structural and chemical features via deep learning and fuses these complementary features through a cross-modal attention mechanism. Without relying on explicit gas-specific thermodynamic descriptors, COFAP achieves state-of-the-art prediction performance on the hypoCOFs dataset under the conditions investigated, outperforming existing approaches. Based on COFAP, we found that high-performing COFs for gas separation concentrate within a narrow range of pore size and surface area. A weight-adjustable prioritization scheme is also developed to enable flexible, application-specific ranking of candidate COFs. Superior efficiency and accuracy render COFAP directly deployable in crystalline porous materials.
SCIENCE CHINA Materials•2025•DOI: 10.1007/s40843-025-3643-8
Inverted perovskite solar cells (PSCs) suffer from defect-mediated nonradiative recombination and inefficient charge extraction, particularly at the buried interface and grain boundaries (GBs), which limit power conversion efficiency (PCE) and operational stability. This study introduces a multifunctional phosphonic acid molecule, (2-(3,6-bis(trifluoromethoxy)-9H-carbazol-9-yl)ethyl)phosphonic acid (M28), as an additive in the perovskite precursor solution. M28 spontaneously segregates toward the buried interface and GBs, fulfilling three roles: (1) slowing crystallization to enlarge grains and improve film quality, (2) passivating defects to suppress charge recombination, and (3) inducing p-type doping to create an extra electric field that promotes hole transport. Devices incorporating M28 achieve a champion PCE of 25.96% and retain 80% of initial efficiency after 1500 h of maximum power point tracking. This work demonstrates the efficacy of multifunctional phosphonic acid additives in addressing buried-interface and GB defects, offering a viable route to high-performance, stable inverted PSCs.