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HJ
Verified CAS / Academic Author24 Decoded Studies

Prof. HU Jie

Tsinghua University

Co-Affiliations:Xinjiang Academy of Environmental Protection Science, Urumqi, 830011, ChinaChinese Academy of Sciences

Research Publications & English Decoded Briefs

Showing 24 publications
SCIENCE CHINA Materials2026DOI: 10.1007/s40843-026-4412-y

Local van der Waals gaps and resonant levels enhance thermoelectric performance of lead-free GeTe

GeTe-based thermoelectric materials are promising lead-free alternatives to PbTe, but their intrinsically high Ge vacancy concentration (~10^21 cm^-3) leads to excessive carrier density and degraded Seebeck coefficient. This study integrates resonant levels (RLs) via In doping and local van der Waals gaps via Sb/Bi alloying to decouple electron and phonon transport. The optimal composition Ge0.91Sb0.04Bi0.04In0.01Te exhibits a Seebeck coefficient of ~287.31 μV K^-1 at 323 K, more than double that of the In-free sample (~102.28 μV K^-1). The peak figure of merit zT reaches ~1.8 at 723 K, with an average zT of ~1.0 over 323–723 K. Vickers hardness is enhanced to ~224 HV, a ~93% improvement over pristine GeTe (~116 HV). X-ray diffraction reveals a structural evolution toward a pseudo-cubic phase with increasing In content, and the (202) peak shifts to lower angles, indicating lattice expansion. These results demonstrate that synergistic RLs and van der Waals gaps effectively optimize carrier concentration and suppress thermal conductivity, offering a viable route for high-performance, mechanically robust GeTe thermoelectrics.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-026-4239-2

Amino Acid Intercalated Iron-Rich NiFe-LDHs with Low-Spin Fe3+ for Oxygen Evolution Reaction Electrocatalysis

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 Materials2026DOI: 10.1007/s40843-026-4360-7

Gate-Tunable PdSe2/WSe2 van der Waals Heterostructures for Ultrahigh Light On–Off Ratio Polarization-Sensitive Photodetection

Polarization-sensitive photodetection is critical for advanced optical communication and imaging systems, yet conventional photodetectors suffer from low on-off ratios and limited polarization discrimination. Here, we report gate-tunable PdSe2/WSe2 van der Waals heterostructures that achieve ultrahigh light on-off ratio and polarization-sensitive photodetection. The heterostructure forms a type-II band alignment, enabling efficient charge separation and self-powered operation. By applying a gate voltage, the photoresponse can be modulated, achieving an on-off ratio exceeding 10^6 under illumination. The device exhibits a high responsivity of 1.2 A/W and a specific detectivity of 10^12 Jones at room temperature. Polarization-sensitive measurements reveal a linear dichroism ratio of 2.1 at 532 nm, attributed to the anisotropic crystal structure of PdSe2. The photodetector operates over a broad spectral range from visible to near-infrared (400-1000 nm) with fast response times (rise/fall < 100 μs). The gate-tunable capability allows dynamic control of the photocurrent, enabling adaptive sensing applications. These results demonstrate that PdSe2/WSe2 heterostructures are promising candidates for high-performance, polarization-sensitive photodetectors, offering a pathway for next-generation optoelectronic devices.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-026-4262-7

Single-gate reconfigurable multifunctional devices based on anti-ambipolar van der Waals heterojunctions

The escalating demands of artificial intelligence, machine learning, and neural computing necessitate multifunctional optoelectronic devices capable of integrating sensing, memory, and processing. Two-dimensional van der Waals heterostructures (vdWHs) offer unique advantages, yet their practical deployment is hindered by complex architectures and inefficient mode-switching. Here, we demonstrate a MoTe2/SnS2 anti-ambipolar heterojunction device enabling single-gate reconfiguration among frequency doubling, broadband photodetection, and neuromorphic computing. The device exhibits a peak-to-valley ratio (PVR) of 465, ensuring efficient frequency doubling. As a photodetector, it operates across an exceptionally broad spectral range of 520–2200 nm, with outstanding responsivity and detectivity. Furthermore, the device emulates complete synaptic behaviors, including short-term plasticity (STP), long-term plasticity (LTP), and paired-pulse facilitation (PPF). Integrated into a reservoir computing (RC) system trained on a vehicle motion dataset, it achieves a directional recognition accuracy of 98.7%. This work establishes a paradigm for multifunctional integration and low-power neuromorphic computing, advancing next-generation intelligent optoelectronic systems.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-026-4176-y

An AIE-active centrosymmetric small molecule for ultra-deep three-photon brain angiography in the NIR-III window

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 Materials2026DOI: 10.1007/s40843-025-3709-4

Enhanced built-in electric field by asymmetric Mo-doped BiVO4 for photoelectrocatalytic detoxification of ofloxacin in hyposaline wastewater

Photoelectrocatalytic (PEC) detoxification of ofloxacin in hyposaline wastewater is hindered by weak built-in electric fields (IEF) and rapid charge recombination. Here, we report a crystal dipole engineering strategy using high-valence Mo-doped BiVO4 to enhance IEF and PEC activity. Mo incorporation breaks lattice symmetry, increasing the crystal dipole moment and amplifying IEF to 2.05 times that of pristine BiVO4. This promotes directional carrier migration, improving electron-hole separation efficiency. The optimized 4% Mo-BiVO4 photoanode achieves 96.5% ofloxacin degradation within 60 minutes and maintains 91.9% degradation efficiency in natural lake water containing saline and organic interferents, demonstrating exceptional anti-interference capability. This work provides a strategy for boosting photocatalytic performance through unit-cell dipole engineering, aiming to enhance sustainability in wastewater treatment.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-3714-3

Topological Chitosan Framework Enables Reversible Columnar Array Anodes for High-Performance Aqueous Zinc Batteries

Eco-friendly aqueous zinc batteries (AZBs) are promising alternatives to lead-acid batteries in applications requiring both safety and energy density. However, their practical deployment is hindered by the synergistic deterioration of zinc anodes—structural collapse and kinetic failure—under high depth of discharge (DOD) and high current densities, which severely limits actual energy and power densities. Here, we report a strategy for the in situ integration of a double-layer topological chitosan framework (D-CTS) on current collectors via regulating phase separation kinetics during multistage coordination-neutralization electrophoresis. The vertical through-hole array is formed by coupling instantaneous and delayed phase separation. Subsequently, a columnar zinc array is mediated by D-CTS to construct an integrated component (D-CTS-Zn) comprising a vertical through-hole separator and an array anode. The embedded interconnected nanonetworks within the through-hole walls enable dynamic equilibrium of the columnar zinc array through a lateral ion compensation mechanism. As a result, Zn||Zn symmetric cells with D-CTS-Zn stably cycle over 3000 cycles at 200 mA cm−2 under 60% DOD. The assembled D-CTS-Zn||MnO2 battery delivers an energy density of 83 Wh kg−1 at an ultrahigh power density of 9.25 kW kg−1. This work provides a constructive strategy for chitosan phase separation regulation and separator-induced reversible metal array anodes.

Journal of Environmental Engineering Technology2026DOI: 10.13205/j.hjgc.202604022

Synergistic Benefits of Pollution Reduction and Carbon Mitigation from Converting Food Waste into Carbon Sources for Wastewater Treatment Plants

The resource utilization of food waste contributes to reducing environmental pollution, driving nutrient cycling and biomass energy development, and promoting the resource recycling industry, achieving a win-win outcome for environment and economy. This study evaluated the resource recovery performance and environmental impacts of producing carbon sources for wastewater treatment through hydrolysis and acidification of food waste, comparing with two conventional alternatives: anaerobic fermentation and incineration. Results showed that among the three technologies, hydrolysis for carbon source production ranked middle in resource recycling efficiency, but its environmental benefits were superior to incineration and anaerobic fermentation. The hydrolysis process did not produce additional wastewater requiring treatment, and its greenhouse gas emissions and solid waste generation intensity were relatively low, at -40.7 kg CO2-eq/t and 9.3%, respectively. Carbon sources derived from food waste can replace commercial alternatives, reducing wastewater treatment costs and promoting synergies between pollution reduction and carbon mitigation. Sensitivity analysis revealed that water content in food waste significantly influences solid impurity generation and energy recovery efficiency of hydrolysis technology. In regions with high food waste generation and carbon source demand, hydrolysis technology is recommended to facilitate large-scale synergistic treatment of wastewater and food waste.

Environmental Chemistry2026DOI: 10.7524/j.issn.0254-6108.2025091205

Temporal Variation Characteristics of Air Pollutants in the Kui-Du-Wu Region of Xinjiang from 2018 to 2024

This study analyzes the spatiotemporal variation characteristics and driving mechanisms of PM2.5, PM10, SO2, NO2, O3, and CO in the Kuytun-Dushanzi-Wusu (Kui-Du-Wu) region of Xinjiang, based on monitoring data from 2018 to 2024. Results indicate that urban sites (e.g., Kuytun Laoganju Station) are influenced by traffic emissions, leading to elevated PM2.5 and NO2 concentrations. Dushanzi District, with petrochemical industry emissions, exhibits notable SO2 and O3 pollution. Agricultural areas (e.g., Kuytun Huaxin Tomato Company) show significant PM10 and CO levels affected by dust and diesel machinery. Over the study period, PM2.5, PM10, NO2, and CO concentrations generally declined at annual rates of 1.5–4.0 μg·m−3·a−1, reflecting the effectiveness of coal substitution, industrial upgrades, and vehicle emission controls. Conversely, O3 concentrations increased consistently at rates of 1.3–3.2 μg·m−3·a−1, highlighting shortcomings in volatile organic compound (VOCs) control. Seasonal patterns show PM and CO peaking in winter due to heating combustion and temperature inversions, and reaching minima in summer due to enhanced diffusion and precipitation. O3 peaks in summer driven by photochemical reactions, contrasting with NO2 winter highs from heating and industrial activities. The findings underscore the need for coordinated control of VOCs and NOx, optimized dust management, and differentiated emission controls for industrial, traffic, and agricultural sources.

Journal of Environmental Engineering Technology2026DOI: 10.13205/j.hjgc.202605021

Nitrogen and phosphorus removal from kitchen waste biogas slurry by ZnCl₂-modified biogas residue biochar in FCDI

The digestate from anaerobic digestion of food waste is separated into solid residue and liquid filtrate. The filtrate retains high nutrient and carbon content, making it a viable resource for recovery. This study prepared biochar from food waste digestate residue and employed it as an electrode active material in a flow-electrode capacitive deionization (FCDI) system, with activated carbon as a control, to assess nitrogen and phosphorus removal from kitchen waste biogas slurry. ZnCl₂ modification significantly enhanced the biochar's specific surface area, adsorption capacity, capacitance, and conductivity. The optimal mass fraction of modified biochar in the electrode liquid was 7.5%. In simulated digestate, the FCDI system achieved removal efficiencies of 47.7% for NH₄⁺-N and 55.2% for reactive phosphorus (RP) over 12 hours. Performance ranking of electrode materials was activated carbon > ZnCl₂-modified biochar > unmodified biochar. In continuous operation with actual anaerobic digestion filtrate, maximum removal efficiencies were 32.2% for NH₄⁺-N and 26.2% for RP. The reduced performance in real digestate is attributed to organic foulants such as peptides and amino acids, which block ion-exchange membrane channels, increase membrane resistance, and impede ion transfer and charge transport, thereby diminishing deionization efficiency.

Journal of Fuel Chemistry and Technology2026DOI: 10.3724/2097-213X.2025.JFCT.0031

High-Temperature Ash Behavior of Biomass: A Comparative Study of Corn and Wheat Straw

The high-temperature behavior of biomass ash critically influences gasifier operational efficiency. This study investigates the differential high-temperature behaviors of corn straw ash (CSA) and wheat straw ash (WSA) using an intelligent ash fusion analyzer, high-temperature rotating viscometer, X-ray diffraction (XRD), SEM-EDS, and FactSage thermodynamic simulations. Both ashes contain high K2O (>30%) and exhibit flow temperatures below 1300 °C. Despite higher K2O and lower SiO2, CSA exhibits a higher flow temperature (1241 °C) than WSA, attributed to elevated CaO (10.39%) and MgO (7.33%) that promote formation of high-melting silicates (K2MgSiO4, K2Ca2Si2O7, CaSiO3). In contrast, WSA with lower CaO (4.92%) and MgO (2.82%) tends to form low-melting potassium silicates. At high temperatures, both slags are typical crystalline slags, with viscosity rising sharply below a critical temperature. For CSA, rapid nucleation and coarsening of silicate crystals (e.g., KAlSiO4 grain size increases from 20.5 nm at 1350 °C to 192.9 nm at 1050 °C) cause abrupt viscosity increase. For WSA, a high P2O5 content (10.05%) induces a 'chemical dilution effect', leading to persistent KAlSiO4 during cooling and elevated viscosity, especially at the final cooling stage. This study elucidates how ash chemical composition governs high-temperature phase equilibrium and non-equilibrium kinetics, thereby macroscopically affecting ash fusion and rheological behavior, providing a theoretical basis for deeper understanding of biomass ash high-temperature characteristics.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-3863-x

Efficient blue-light-excitable broadband NIR emission in Mo4+-doped double perovskite with robust thermal stability and efficient X-ray scintillation for pixel-level X-ray to NIR image fusion

Lead-free double perovskites are promising for optoelectronic applications due to their tunable optical properties, stability, and non-toxicity. However, achieving efficient ultrabroadband near-infrared (NIR) emission and X-ray radioluminescence (RL) simultaneously remains challenging. Here, we report a Mo4+-doped Cs2(Na0.4Ag0.6)InCl6 double perovskite that exhibits efficient blue-light-excitable NIR emission with a near-unity photoluminescence quantum yield. The emitter demonstrates robust thermal stability, retaining 84% of its initial emission intensity at 420 K relative to 300 K. Under X-ray irradiation, the material shows bright NIR RL with a high light yield of 39,400 ± 1100 photons/MeV. A flexible film of Mo4+-doped Cs2(Na0.4Ag0.6)InCl6/polydimethylsiloxane (PDMS) was fabricated and applied as an NIR light source and X-ray scintillator. A dual-functional platform for cooperative NIR and X-ray imaging was established using a bullfrog palm as the target, achieving pixel-level fusion of NIR and X-ray images without spatial mismatch or complex image processing. The fused image simultaneously visualizes blood vessels and skeleton textures under the skin tissue. This work provides a viable strategy for lead-free double perovskites in advanced optoelectronic devices, particularly for multispectral imaging.

Environmental Chemistry2026DOI: 10.7524/j.issn.0254-6108.2025032004

Research and Application of County-Town Scale Air Pollution Tracing Method

This study proposes an integrated source apportionment framework that synergistically integrates pollution source classification, atmospheric dispersion modeling, backward trajectory analysis, weighted trajectory clustering, and forward contribution estimation to accurately target peak reduction at localized air pollution hotspots. Applied at the County-Town Scale in Beijing, this method was employed to investigate pollution episodes at the Tongzhou Dongguan monitoring site. Source classification relied on a pollution fingerprint database and temporal concentration profiles, while local contributions were quantified through combined air quality modeling and monitoring data. Forward and backward trajectory analyses enabled the identification of potential source regions and key contributors. Results indicate that construction dust, road dust, and emissions from the catering industry were the dominant local sources, with construction and road dust contributing most prominently to PM2.5 concentrations. Furthermore, abnormal PM2.5 increases were closely linked to low boundary layer height, weak winds, and high humidity, emphasizing the role of meteorological conditions in pollution accumulation. The proposed framework proves effective in pinpointing local pollution sources and offers a scientific basis for targeted air quality management at finer spatial scales.

Environmental Chemistry2026DOI: 10.7524/j.issn.0254-6108.2025031102

Rational Design of Laccase Mutants for Enhanced Catalytic Degradation of Benzene-Containing Pollutants: A Computational Insight into Binding Pocket Engineering

Laccases are promising biocatalysts for environmental remediation, yet their application is hindered by the instability and limited substrate affinity of wild-type enzymes. Here, we report a computational strategy integrating homology modeling, molecular docking, and virtual mutagenesis to engineer high-performance laccase mutants targeting benzene-containing pollutants. Structural analysis revealed that fungal laccase (Trametes versicolor, T.v) exhibited stronger binding affinities for aniline, o-phenylenediamine, and 1-hydroxybenzotriazole (HBT) compared to bacterial laccase (Bacillus subtilis, B.s), attributed to optimized hydrophobic and hydrogen-bond interactions within the substrate-binding pocket. Virtual mutagenesis identified critical residues (e.g., Ser113, Leu459) regulating substrate stability. Notably, mutations at Ser113 to Arg/Glu/Leu significantly enhanced binding energy (ΔG ≤ −7.1 kcal·mol−1 for HBT) by narrowing the pocket exit and reinforcing hydrophobic constraints. Mechanistically, polar mutations in the pocket interior promoted hydrogen bonding, while hydrophobic substitutions at peripheral residues restricted substrate dissociation. Our findings establish a dual-region engineering principle—enhancing hydrogen bonds internally and hydrophobicity externally—to optimize laccase activity. This work provides a generalizable framework for the rational design of oxidoreductases in pollutant degradation.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-4012-4

Multi-stimuli-responsive phase change hydrogels with dynamic fluorescence chromism based on AIE hydrophobic carbon dots for advanced encryption

Stimuli-responsive fluorescent hydrogels, owing to their tunable optical properties and unique smart response characteristics, have significant potential in encryption applications and information security. However, most current systems are limited to single-stimulus responsiveness and lack the capability for programmable information erasure or multi-modal dynamic synergy. Hence, we propose a multi-stimuli-responsive phase-change hydrogel incorporating aggregation-induced emission hydrophobic carbon dots (AIE-HCDs) and polyethylene glycol (PEG)-cellulose network, demonstrating dynamic fluorescence chromism under various external triggers. The hydrogel exhibits solvent-exchange-triggered fluorescence color changes from blue to red, enabled by the concentration modulation of AIE-HCDs through the exchange between PEG and water. Additionally, the temperature-induced phase transition of PEG from crystalline to molten state modulates the aggregation and dispersion of AIE-HCDs, thereby enabling dynamic fluorescence color changes. The phase transition further confers excellent shape-memory behavior and adjustable mechanical properties, with the tensile modulus varying from 6.28 MPa in the molten state to 36.23 MPa in the crystalline state, while maintaining high transparency (~88% in the molten state). By utilizing micro-contact printing and the multi-stimulus response, an encryption platform enables information to be hidden, selectively read under sequential stimuli (thermal, UV, and solvent), and completely erased upon demand. This strategy demonstrates significant potential for advancing high-level information encryption and anti-counterfeiting technologies.

Chinese Journal of Environmental Engineering2026DOI: 10.12030/j.cjee.202511027

Nutrient Release Characteristics of Aquaculture Sludge through Anaerobic Acidification in an Aquaponics System

Aquaponics systems integrate aquaculture and hydroponics to recycle resources, yet nutrient recovery from aquaculture sludge remains inefficient. This study investigated anaerobic acidification as an alternative to conventional anaerobic digestion, which suffers from long conversion cycles. Batch experiments compared two sludge loading rates: high (13.22 kg·kg−1) and low (4.61 kg·kg−1) (mass of sludge per mass of anaerobic inoculum). Under low loading, soluble chemical oxygen demand (SCOD) exhibited a single peak, reaching a maximum organic solid conversion of 68.2% at 70.5 h. In contrast, high loading produced three SCOD peaks with an average peak conversion efficiency of only 26.9% at 27.5 h and higher residual concentrations. Ammonia nitrogen conversion was slightly higher under low loading (64.8%) than high loading (62.2%), while orthophosphate conversion was markedly superior (95.7% vs. 76.4%). The optimal hydraulic retention time for low-loading operation was 144 h, corresponding to an organic loading rate of 0.77 kg·(kg·d)−1. Under these conditions, the produced ammonia and phosphate can be effectively recovered without adversely affecting water quality, as the biofilter converts ammonia to nitrate for plant uptake. Microbial analysis revealed that low-loading conditions favored the dominance of Acinetobacter (relative abundance 66.6%), which likely enhances organic degradation and nutrient release. These findings demonstrate that anaerobic acidification under low loading is a promising strategy for efficient nutrient recovery in aquaponics, offering a shorter conversion time and higher nutrient yields than traditional methods.

Environmental Chemistry2026DOI: 10.7524/j.issn.0254-6108.2025111403

Heavy Metal Pollution Characteristics and Ecological Risk Assessment of Sediments in the Hengyang Section of the Xiang River

Sediments from the Hengyang reach of the Xiangjiang River were analyzed for concentrations, chemical fractions, and sources of 14 heavy metals (As, Se, Cd, Sb, Pb, Tl, Bi, Co, Ni, Mn, Zn, V, Cr, Cu). Mean concentrations of As, Se, Cd, Sb, Pb, Tl, and Bi exceeded local background values, with Cd, Se, Bi, and As showing pronounced enrichment. Spatial heterogeneity was marked, with higher levels downstream; overall concentrations were lower than previously reported. Sequential extraction revealed that Sb, Bi, Se, Tl, Cu, As, V, Cr, and Ni were predominantly in the residual fraction (F4), while Zn, Cd, Pb, and Mn had higher extractable fractions (F1+F2+F3), with bioavailable fractions generally elevated downstream. Geo-accumulation index (Igeo) indicated no contamination by Co, Zn, V, or Cr, but varying degrees of contamination by Mn, Ni, As, Se, Cd, Sb, Pb, Tl, Bi, and Cu, with pollution severity order: Se>Cd>Bi>As>Sb>Pb>Tl>Ni>Cu>Mn>Zn>Cr>Co>V. Enrichment factors showed significant enrichment for Cd, Sb, and Bi, moderate for Pb, and low for others. Potential ecological risk index (RI) revealed Cd as the primary contributor (87.49% of total risk), with overall moderate risk at downstream sites and slight risk across the entire section. Source apportionment using PCA and PMF identified three sources: industrial and traffic mixed source (57.60%), natural source (16.00%), and industrial-natural mixed source (26.40%). These findings enhance understanding of heavy metal pollution mechanisms in the Hengyang section and recommend priority control of industrial and traffic emissions, with focus on Cd mobility, to support sediment remediation strategies.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-4014-3

Pressure-Driven Laser-Induced Graphene: Transient Pressure-Enhanced Structural Ordering via Femtosecond Laser Irradiation

Laser-induced graphene (LIG) methods, including photothermal and photochemical approaches, are promising for flexible electronics yet face distinct limitations. Photothermal methods often produce graphene with uncontrolled structural and functional properties, while photochemical methods are restricted to a narrow range of precursors. To address these limitations, we propose a pressure-driven LIG (P-LIG) method that uses transient laser-generated pressure fields as an additional control parameter to improve graphene quality. An integrated framework combining ultrafast pump–probe interferometric imaging, large-scale molecular dynamics (MD) simulations, and explainable artificial intelligence (XAI) was developed to investigate this approach. Time-resolved measurements reveal the generation of transient pressure fields during femtosecond laser irradiation of polyimide films, confirming pressure as an intrinsic feature of the process. MD simulations under controlled pressure conditions demonstrate that pressure promotes the nucleation and stacking of graphene layers, resulting in more continuous and planar graphitic networks. XAI analysis quantitatively identifies the important contributions of pressure. These results confirm that the transient pressure introduced by the P-LIG method plays a key role in promoting more ordered, continuous, and planar graphene networks, and enhancing structural integrity and material quality beyond traditional methods. This provides a practical pathway for improving the performance and reliability of LIG-based flexible electronic devices.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-026-4196-x

A Critical Artifact in Aqueous Zinc-Ion Batteries: Charging under Aerial Oxidation Distorts Discharged-Cathode Characterization

Aqueous zinc-ion batteries (AZIBs) are promising for safe, low-cost energy storage, but accurate cathode characterization is essential for understanding their electrochemical behavior. This study identifies a critical artifact: routine air-drying of deeply discharged cathodes triggers spontaneous aerial oxidation, which distorts post-mortem analysis. Using NH4V4O10 (NVO) as a model cathode, we show that ex situ X-ray photoelectron spectroscopy (XPS) of discharged electrodes reveals only V4+/V5+ signals, with no detectable V3+, implying a theoretical capacity of only 245.5 mAh g−1, yet experimentally measured capacity reaches ~334.5 mAh g−1 at 0.2 A g−1. This discrepancy arises because air exposure during sample preparation oxidizes the reduced vanadium states, leading to a self-charging effect that recovers ~83% of capacity. Electrochemical re-oxidation (EO-NVO) is superior to aerial oxidation (AO-NVO), producing a stable, long-range ordered bulk structure with efficient Zn2+ transport channels, whereas aerial oxidation induces only superficial changes and structural disorder. These findings resolve a key analytical inconsistency and reveal a novel capacity-contribution pathway, with direct implications for accurate material assessment and advanced battery design.

SCIENCE CHINA Materials2025DOI: 10.1007/s40843-025-3336-4

A Highly Efficient NIR-II-Emitting MgGa2O4:Cr3+,Ni2+ Phosphor via Cr3+ Ions in Tetrahedral Sites as the Cr3+-Ni2+ Energy Transfer Bridge

The Ni2+ ion exhibits broadband near-infrared (NIR) II emission (1000–1700 nm) but suffers from low absorption efficiency and cannot be effectively excited by blue light chips, impeding commercial application. This study introduces Cr3+ sensitizer ions into MgGa2O4:0.01Ni2+, markedly enhancing blue-light absorption and photoluminescence. The optimized MgGa2O4:0.24Cr3+,0.01Ni2+,2 wt% H3BO3 sample exhibits broadband emission from 1000 to 1600 nm with a peak at 1290 nm, achieving internal and external photoluminescence quantum yields of 81.91% and 62.51%, respectively. Comprehensive optical characterization, X-ray absorption near-edge structure spectra, and low-temperature photoluminescence spectra determine that Cr3+ ions occupy tetrahedral sites, and their energy level acts as an intermediate for efficient Cr3+→Ni2+ energy transfer. The packaged NIR phosphor-converted light-emitting diode (pc-LED) demonstrates an electro-optical conversion efficiency of 11.38% at 20 mA and a NIR output power of 52.66 mW at 350 mA, showcasing exceptional performance for NIR-II applications.

SCIENCE CHINA Materials2025DOI: 10.1007/s40843-025-3335-6

Nickel-Mediated Formation of Stable Frustrated Lewis Pairs in Rare Earth MOFs for Dicyclopentadiene Hydrogenation

Rare earth metal-organic frameworks (RE-MOFs) exhibit limited active site density and insufficient thermal stability, constraining their catalytic utility. This study employs heteroatom doping and defect engineering to synthesize RE-Ni-BTC materials. Nickel incorporation into RE-MOFs alters charge distribution and crystal structure stability, generating atomic-scale defects that induce RE–O frustrated Lewis pairs (FLPs) and a distinct Ni–O4 coordination motif. Nd-Ni-BTC surpasses Ce-Ni-BTC due to enhanced Lewis acid-base properties and superior substrate adsorption/desorption, achieving complete dicyclopentadiene (DCPD) conversion and at least seven recycling cycles under 100 °C, 2 MPa H2, and 10 h. The approach balances catalytic activity and stability without structural degradation, offering a route for defective MOFs in hydrogenation catalysis and catalyst design.

SCIENCE CHINA Materials2025DOI: 10.1007/s40843-025-3382-4

Coordination-directed ternary MOF-on-MOF-derived bimetal phosphide-carbon nanomaterials for efficient overall water splitting

The development of efficient, durable, and cost-effective electrocatalysts for overall water splitting (OWS) is critical for sustainable hydrogen production. Noble metal-based catalysts (Pt, Ru, Ir) exhibit high activity but suffer from scarcity and poor stability, while transition metal-based alternatives often lack sufficient active site utilization and mass transport. This work presents a coordination-directed synthesis of a ternary MOF-on-MOF heterostructure (ZIF-67@MOF-74@PBA) that serves as a precursor for bimetallic CoFeP nanoparticles anchored on hierarchically porous carbon nanomaterials with in situ grown carbon nanotubes (CNTs). The resulting catalyst features hollow structures with high site exposure, efficient mass and charge transport pathways, and synergistic effects from multiple transition metals. In 1.0 M KOH, the catalyst achieves a hydrogen evolution reaction (HER) overpotential of 107 mV at 10 mA cm−2, an oxygen evolution reaction (OER) overpotential of 231 mV at 10 mA cm−2, and an overall water splitting voltage of 1.544 V at 10 mA cm−2, with remarkable long-term stability. Apparent activation energy measurements and density functional theory (DFT) calculations reveal that the in situ integration of bimetals and phosphorus doping enhance O–O coupling in the OER and optimize hydrogen adsorption/desorption in the HER. This synthesis strategy offers a versatile approach for designing multi-level MOF-on-MOF systems as high-performance electrocatalysts, addressing the limitations of conventional transition metal catalysts in industrial water electrolysis.

SCIENCE CHINA Materials2025DOI: 10.1007/s40843-025-3620-x

Purely Zwitterionic Polymer Injectable Hydrogels for Vitreous Substitutes

Current clinical vitreous substitutes, including inert expansile gases, silicone oil, and perfluorocarbon liquids, are associated with complications such as emulsification, cataract formation, glaucoma, and inflammation, necessitating safer alternatives. This study reports a purely zwitterionic polymer hydrogel constructed entirely from carboxybetaine ureido acrylate (CBUIA) without covalent cross-linkers or non-zwitterionic segments. The hydrogel self-crosslinks via multivalent hydrogen bonding and dipole-dipole interactions, forming a supramolecular network of poly(carboxybetaine ureido acrylate) (PCBUIA). The PCBUIA hydrogels exhibit shear-thinning injectability and rapid self-healing, with density (1.016–1.021 g/cm³), refractive index (1.3359–1.3389), and transmittance (>90%) matching native vitreous. The zwitterionic hydration layer confers ultralow protein adsorption and suppresses cell attachment, with no foreign-body reaction or fibrotic capsule formation. After one month of implantation in rabbit eyes, the hydrogels maintained optical transparency, preserved retinal morphology, and did not elevate intraocular pressure or cause inflammatory responses. These findings demonstrate the potential of purely zwitterionic polymer hydrogels as vitreous substitutes, though further long-term in vivo studies are required to evaluate stability and functional performance.

SCIENCE CHINA Materials2025DOI: 10.1007/s40843-025-3495-8

High-performance β-Ga2O3 solar-blind UV/X-ray photodetector enhanced by oxygen vacancy modulation

β-Ga2O3 metal-semiconductor-metal photodetectors were fabricated on MOCVD-grown films with controlled oxygen vacancy content via the Foxy/FTEGa precursor ratio. Increasing Foxy/FTEGa improved crystallinity and reduced oxygen vacancy concentration. The optimal device exhibited a dark current of 30.9 fA, a photo-to-dark current ratio of 8.7 × 10^8, and a responsivity of 237 A W−1 under 254 nm solar-blind ultraviolet illumination, with rise/decay times of 155/34 ms. Under X-ray irradiation, the detector achieved a sensitivity of 10,736 μC cm−2 Gy_air−1, 477 times higher than conventional a-Se detectors, and maintained stable performance during prolonged X-ray exposure. Energy-band analysis under different photoinjection conditions clarified the distinct roles of oxygen vacancies in SBUV and X-ray photoresponse, linking defect density to responsivity and response speed. These findings provide a mechanistic framework for engineering Ga2O3-based detectors with optimized comprehensive performance for astronomical imaging, medical diagnostics, and harsh-environment applications.