SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4433-5
Negative thermal expansion (NTE) and zero thermal expansion (ZTE) materials are technologically relevant for precision engineering, yet their practical deployment is constrained by narrow operating temperature windows. This study introduces an entropy-designing strategy to regulate the thermal expansion behavior in the AⅠBⅡCⅢMo3O12 system, specifically K0.4(Mg0.25Mn0.25Co0.25Ni0.25)0.4Sc1.6Mo3O12 (CE0.4MO) and related CExMO compositions (x = 0.4, 0.6, 0.8, 1.0). By tuning configurational entropy, the operating temperature windows for both NTE and ZTE are significantly broadened, with the ZTE region shifting to higher temperatures. Among single-phase compositions, CE0.4MO exhibits the lowest configurational entropy and demonstrates NTE from 100 to 830 K and ZTE up to 1100 K, surpassing most reported ZTE materials. Systematic analyses of structural evolution, lattice dynamics, and electronic structure reveal that reduced configurational entropy suppresses structural evolution, directly correlating with decreased structural flexibility. Higher atomic displacement parameters (ADPs) of oxygen in CE1.0MO provide experimental evidence for enhanced flexibility. Raman spectroscopy shows that the full width at half maximum (FWHM) of peaks in the 750–900 cm-1 range positively correlates with configurational entropy, indicating reduced lattice disorder, while modes within 750–1050 cm-1 blue-shift as entropy decreases, confirming lattice stiffening. Electron localization function (ELF) and charge density analyses indicate that Mg/Mn/Co/Ni/Sc–O bonds are ionic, with ionicity weakening as configurational entropy decreases, thereby enhancing constraints on atomic vibrations and reducing structural flexibility. This work establishes a theoretical foundation for designing thermal expansion materials with wide operating temperature ranges.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3865-1
Seawater electrolysis (SWE) is a reusable and convenient avenue for producing hydrogen, offering a promising solution to the energy crisis and global warming. However, poor electrolytic efficiency and irreversible corrosion caused by high concentrations of chlorine severely hinder the commercialization of SWE. To address these challenges, numerous strategies have been proposed in recent years, involving theoretical innovations, directional catalyst design, and electrolyser modification. This review provides a systematic summary of the chlorine-related challenges and solutions encountered in SWE. The chlorine-related theoretical knowledge and challenges in SWE systems are first emphasized. Subsequently, multiple anodic chloride suppression strategies are introduced from three aspects: directional regulation of oxygen evolution catalysts, optimization of electrolyte compositions, and ingenious upgrades of electrolytic cells. Finally, future challenges and development directions for large-scale application of SWE technology are explored. This review offers an in-depth analysis of the chlorine-related challenges encountered in the industrialization of SWE, aiming to accelerate the advancement of this technology toward practical applications.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202605005
Water quality prediction is essential for river basin management, yet existing models often struggle with non-stationary, noisy monitoring data. This study collected water quality data from two city-level control sections in southern China from December 2020 to June 2024, including eight indicators: water temperature, turbidity, pH, conductivity, dissolved oxygen (DO), ammonia nitrogen (NH4+-N), total phosphorus (TP), and permanganate index (CODMn). To predict four key indicators (DO, NH4+-N, TP, CODMn), we developed hybrid models combining seasonal trend decomposition (STD), Bayesian hyperparameter optimization, and either random forest (RF) or XGBoost. STD smoothed and denoised the data while extracting seasonal factors; Bayesian optimization tuned model hyperparameters. Evaluation showed that the STD-Bayesian-XGBoost model achieved smaller bias errors and higher prediction accuracy than STD-Bayesian-RF. Specifically, XGBoost reduced root mean square error (RMSE) by 15-20% across all four indicators and improved the coefficient of determination (R²) to above 0.90, compared to RF's 0.85-0.88. The models were validated on southern river data, but the methodology is generalizable to other climatic and hydrological settings. This work provides a technical reference for pollution reduction and carbon management in regional watersheds.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202511090
In ecological restoration projects such as wetland reconstruction and mine reclamation, seedling transplantation or mechanical damage often leads to slow healing, reducing survival rates and weakening carbon sequestration and soil-water conservation functions. To address secondary pollution from traditional chemical remediation, this study developed a self-powered piezoelectric hydrogel for green electrical stimulation of plant wounds. The hydrogel, based on polyacrylamide/polyethylene glycol (PAM/PEG) with CaCl2, formed a microporous, locally ordered piezoionic network. Characterization included microstructure, piezoionic response, and water retention. At 30 °C and 55% relative humidity, the hydrogel retained about 70% mass after 80 h of continuous water loss. Under simulated environmental mechanical forces, the hydrogel generated a peak voltage of approximately 6 mV. In tomato seedling stem models, wound callus area ratios reached approximately 49.50%, 64.87%, and 86.13% at 3, 5, and 10 days, respectively, when the hydrogel was attached and driven by environmental forces. The PAM/PEG/CaCl2 hydrogel efficiently converts environmental mechanical energy into mild electrical signals, promoting plant wound healing, reducing exogenous chemical use, and offering a low-carbon, environmentally friendly material pathway for ecological restoration and urban green space management.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3862-x
Hexagonal boron nitride (hBN) is indispensable for next-generation electronics and quantum technologies, yet controlled synthesis of isotopically engineered hBN with macroscopic scalability and atomic-level precision remains challenging. Here, we present a plasma-enhanced chemical vapor deposition (PECVD) method using elemental boron (B) and nitrogen (N) precursors to achieve wafer-scale growth and precise isotopic control of hBN films. High-quality hBN films are synthesized on Cu substrates via optimized B evaporation and N2 plasma activation. The growth mechanism involves an oxygen-mediated pathway for B transport and a layer-by-layer (Frank-van der Merwe) mode for multilayer formation. By employing isotopically enriched B powders (10B and 11B) and N2 gases (14N2 and 15N2), we demonstrate tunable isotopic compositions with phonon mode shifts quantitatively matching harmonic oscillator predictions. Furthermore, we realize unprecedented in-plane h10BN-h11BN heterostructures through dynamic B source switching during growth. This PECVD strategy establishes a transformative synthesis platform merging industrial-scale production capacity with atomic-scale isotopic precision, enabling new opportunities to engineer thermal transport, optical response, and quantum coherence in two-dimensional materials.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3869-7
Iontronic capacitive pressure sensors (ICPSs) are pivotal for wearable technology, yet their performance is constrained by an inherent trade-off between sensitivity and detection range. Here, we introduce a micro-electric double layer (micro-EDL) engineering strategy to overcome this limitation. This is realized through a nanocomposite dielectric where multi-walled carbon nanotubes (MWCNTs) form a percolated network, generating a dense array of pressure-responsive nano-capacitors. Synergistically integrating a hierarchical MoS2/NiCo-LDH electrode provides abundant pseudocapacitive interfaces. The resulting sensor exhibits an ultrahigh sensitivity of 67,095 kPa−1 at 1 kHz, a broad detection range up to 1.3 MPa, rapid response and recovery times of 4 ms and 5 ms, respectively, and outstanding durability exceeding 18,000 cycles. Practical validation demonstrates 100% classification accuracy in recognizing complex gestures and gait patterns, underscoring its real-world applicability. These findings establish micro-EDL engineering as a promising route for advancing next-generation iontronic devices, offering insights into their electrochemical mechanisms.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3917-x
The escalating global challenge of antibiotic contamination demands advanced sensing technologies for environmental monitoring and public health protection. Here, we present a structurally well-defined, intercalation-engineered metal-organic framework (MOF), HSB-W18, which functions as an ultrasensitive and selective fluorescence sensor for fluoroquinolone antibiotics. Single-crystal X-ray diffraction analysis unambiguously determined both the framework architecture and the spatial organization of intercalated 2,5-dihydroxyterephthalate molecules at atomic resolution. Through ultrasound-assisted synthesis, highly stable book-shaped microsheets (HSB-W18-MS) were obtained, maintaining exceptional aqueous dispersibility and luminescence intensity for over one month. These microsheets offer distinct advantages for antibiotic detection: specific recognition of diverse fluoroquinolones via unique fluorescence signatures; highly sensitive ratiometric detection of enoxacin (ENX) with a limit of detection (LOD) of 5.62 nM and rapid response kinetics (<30 s); exceptional selectivity alongside reusability. Systematic mechanistic investigations revealed a synergistic detection process involving multiple photophysical pathways. Furthermore, a smartphone-based portable detection system was successfully implemented, and the practical utility of the sensor was validated by quantifying ENX in complex environmental samples: tap water LOD = 18.32 nM and river water LOD = 29.87 nM. This study contributes to fundamental materials science and environmental monitoring by elucidating discernible structure-property relationships in intercalated MOFs, demonstrating a robust platform for field-deployable antibiotic detection and proposing an innovative design paradigm for environmental optical sensors.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3991-3
Ionic covalent organic frameworks (ICOFs), as an emerging subclass of covalent organic frameworks (COFs), have garnered significant attention owing to their unique integration of structural precision and ionic functionality. Although conventional neutral COFs possess excellent crystallinity, tunable porosity, and high stability, their limited electronic tunability and poor charge-transport properties have constrained their performance in various applications. The incorporation of ionic sites into COF skeletons or pore environments effectively overcomes these intrinsic limitations. The presence of charged centres enhances framework polarity, modulates local electrostatic fields, and facilitates efficient ion migration and charge separation, thereby endowing ICOFs with superior functionality. As a result, ICOFs have demonstrated remarkable potential in diverse fields, including adsorption, sensing, ion conduction, energy devices, photocatalysis, and electrocatalysis. This review provides an integrative perspective by systematically linking framework design, ionic site engineering, structure-property relationships, and functional performance in various applications, highlighting ICOFs distinct advantages over neutral COFs and providing fundamental insights for the rational design of next-generation ionic frameworks toward energy and environmental applications.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4035-5
Electrocatalytic CO2 reduction reaction (CO2RR) to formate offers a promising pathway for storing renewable electricity in chemical fuels and enabling carbon recycling. The development of efficient and stable catalysts for this specific pathway, however, remains a central challenge. Heteroatom doping can significantly tune the interaction between active sites and key intermediates, boosting catalytic performance. Conventional doping in Bi-based catalysts often relies on uncontrollable in-situ electrochemical processes, leading to ineffective bulk incorporation. Here, we present a simple pre-doping strategy that enables precise doping at surface active sites, thereby enhancing electrochemical performance. The resulting catalyst achieves >95% Faradaic efficiency for formate across 100–500 mA cm−2 in a flow cell and maintains >95% efficiency for over 70 h at 100 mA cm−2 in a membrane electrode assembly, outperforming pure Bi and Bi2S3. A solar-driven system further demonstrates a 4.4% solar-to-formate conversion efficiency. Mechanistic studies reveal that sulfur doping increases electron density, stabilizes the key *OCHO intermediate, and suppresses hydrogen evolution. These findings provide valuable insights into the precise pre-doping modulation of surface active sites for designing highly efficient and stable CO2RR catalysts.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4016-3
Rare earth-based electromagnetic wave (EMW) absorbing materials are promising due to their strong dielectric and magnetic loss capabilities, yet effective enrichment and utilization of rare earth ions remain challenging. Here, an anionic imidazolium-based metal-organic framework (MOF), MOZ-200, is employed to enrich multiple rare earth ions (La3+, Ce3+, Pr3+, Nd3+, Y3+) via host-guest interactions. The anionic framework uniformly confines these ions, which are converted in situ into highly dispersed high-entropy rare earth alloy nanoparticles during carbonization. The resulting HE@C composites feature a conductive, graphitized carbon matrix with abundant multi-scale polarization centers and heterogeneous interfaces, enhancing dipole polarization, interface polarization, and conductive loss. Consequently, the material achieves excellent EMW absorption in the Ku band, with a minimum reflection loss of -79.20 dB and a maximum effective absorption bandwidth of 5.23 GHz. Integrated into a polyurethane matrix, a multifunctional flexible device is realized, offering EMW absorption, photothermal heating, microwave de-icing, and hydrophobicity. This work provides a feasible strategy for rare earth ion utilization and advances the design of flexible multifunctional EMW absorbing materials.