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Verified CAS / Academic Author11 Decoded Studies

Prof. Fei Han

University of Science and Technology Beijing

Research Publications & English Decoded Briefs

Showing 11 publications
SCIENCE CHINA Materials2026DOI: 10.1007/s40843-026-4339-7

Optoelectronic Memristors Based on ZnS-Passivated CdZnSe Quantum Dots for Neuromorphic Synaptic Emulation Enabling Information Encryption

Neuromorphic computing demands energy-efficient synaptic devices that emulate biological plasticity. Optoelectronic memristors based on colloidal quantum dots (QDs) offer tunable bandgaps and solution processability, yet suffer from defect-mediated nonradiative recombination and instability. Here, we report ZnS-passivated CdZnSe core/shell QDs as the active layer in memristive devices, achieving enhanced synaptic emulation and information encryption. Time-resolved photoluminescence (TRPL) decay curves were fitted with a tri-exponential function, revealing that ZnS passivation suppresses defect-related trap states, prolonging the average carrier lifetime from 12.3 ns (CdZnSe) to 28.7 ns (CdZnSe/ZnS). The intensity proportion of the fast decay component (τ1 ≈ 1.2 ns) decreased from 45% to 18%, indicating reduced surface trapping. Devices incorporating CdZnSe/ZnS QDs exhibit stable bipolar resistive switching with an ON/OFF ratio exceeding 10^3, endurance of >10^3 cycles, and retention of >10^4 s. Under 365 nm UV illumination, the devices show light-tunable synaptic plasticity, including paired-pulse facilitation (PPF) with a facilitation index of 180% at a 50 ms interval, and transition from short-term to long-term memory. The memristors successfully emulate essential synaptic functions and are employed in a simple encryption scheme, demonstrating the potential of defect-passivated QDs for secure neuromorphic hardware.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-026-4315-2

Ultra-high-crystallinity transparent glass-ceramic scintillators for high-temperature X-ray imaging

High-temperature X-ray imaging demands scintillators with high crystallinity, efficient scintillation, and robust thermal stability, yet suitable materials remain scarce. Here, we report an ultra-high-crystallinity transparent glass-ceramic (GC) scintillator strategically designed via controllable heat-treatment-induced crystallization. A sequential precipitation method is employed, where cubic CaF2 nanocrystals initially form, subsequently promoting heterogeneous nucleation and growth of hexagonal BaAl2Si2O8. Intrinsic nanoscale phase separation into F-rich and O-rich domains significantly reduces atomic diffusion distances, yielding an unprecedented crystallinity of up to 97.6%. Notably, defect traps (oxygen vacancy defects, likely located within the lattice or at crystalline/amorphous interfaces) enable efficient carrier capture and thermally stimulated release, contributing to remarkable resistance to thermal quenching. Consequently, the GC scintillator maintains 90.6% of its integrated X-ray excited luminescence (XEL) intensity at 300 °C, with the integrated XEL intensity reaching 94.2% of commercial Bi4Ge3O12 (BGO) at room temperature. This enables stable high-temperature X-ray imaging with a spatial resolution of ~10.4 lp mm−1 up to 225 °C. This work provides a versatile pathway for developing high-sensitivity scintillators for extreme-environment X-ray imaging.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-3684-4

Directed charge transfer over GM/UiO-66 ternary heterojunction for enhanced photocatalytic nitrogen fixation

The efficient conversion of dinitrogen (N2) to ammonia (NH3) under mild conditions remains a critical challenge for sustainable nitrogen fixation. This study reports a rationally designed ternary heterojunction, GO/MXene/UiO-66 (GM/UiO-66), which achieves directed charge transfer for enhanced photocatalytic nitrogen fixation. The internal electric field at the heterointerface drives anisotropic migration of photogenerated charges, leading to rapid separation of electron–hole pairs and suppression of interfacial recombination. The intrinsic defect structure of graphene oxide (GO) provides active sites for N2 adsorption and activation, while π–π interactions between GO and UiO-66 accelerate electron transfer. Additionally, the Schottky junction between UiO-66 and MXene facilitates hole (h+) transfer. The incorporation of GO and MXene extends visible-light absorption of UiO-66. Under simulated solar illumination, GM/UiO-66 exhibits an NH3 generation rate of 25.1 μmol g−1 h−1, which is 1.9 times higher than that of pristine UiO-66 (13.5 μmol g−1 h−1). This work presents a novel strategy for designing ternary heterojunction composites that optimize charge transfer and significantly improve photocatalytic performance.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-3727-0

Multilevel Encapsulation-Engineered Ultra-Stable Flexible Scintillator Films for High-Resolution X-ray Imaging

Lead halide perovskites are promising scintillators for X-ray imaging due to high X-ray absorption efficiency, excellent luminescence, and facile synthesis. However, their ionic nature challenges simultaneous high photoluminescence efficiency and environmental robustness. This work introduces a multilevel encapsulation strategy: CsPbBr3 quantum dots (QDs) are sequentially coated with Cs4PbBr6, SiO2, and polydimethylsiloxane (PDMS). Cs4PbBr6 passivates surface defects, while SiO2 and PDMS provide barriers against moisture, heat, and radiation. The resulting CsPbBr3@Cs4PbBr6/SiO2/PDMS flexible films exhibit a photoluminescence quantum yield (PLQY) of 85%, outstanding mechanical flexibility, and durability under stretching, bending, and compressing. Films retain emission stability under elevated temperatures, prolonged X-ray irradiation, and extended water immersion. X-ray imaging demonstrates spatial resolution of 12 lp/mm, enabling distortion-free imaging of curved objects; superior water resistance allows long-term underwater imaging. This work highlights hierarchical encapsulation in balancing luminescence efficiency and stability, offering a pathway toward practical flexible perovskite scintillators.

Environmental Chemistry2026DOI: 10.7524/j.issn.0254-6108.2024112806

Mechanisms of Natural Organic Matter in Regulating Microplastic Aggregation and Transport in Soil-Groundwater Systems: A Review

Microplastics (MPs) are persistent emerging contaminants ubiquitously distributed in soil-groundwater environments, where their aggregation and transport critically govern pollutant fate and ecological risks. Natural organic matter (NOM), a complex assemblage of organic compounds, interacts with MPs and porous media via hydrogen bonding, π-π interactions, hydrophobic effects, and electrostatic binding, thereby modulating MP surface properties and environmental behavior. This review systematically synthesizes the mechanisms by which NOM influences MP aggregation and transport, with emphasis on the distinct roles of humic substances, proteins, and extracellular polymeric substances (EPS), and their synergistic modulation with solution chemistry (pH, ionic strength, ion type). Additionally, NOM accelerates MP aging and alters surface characteristics, consequently impacting transport capacity. Current research limitations are identified, and future directions are proposed to inform MP pollution risk assessment and management strategies. Key findings indicate that NOM generally enhances MP stability and mobility at low ionic strengths, while high ionic strengths may induce aggregation depending on NOM type and ion valence. Humic substances predominantly increase electrostatic repulsion, whereas proteins and EPS can bridge particles, promoting aggregation. Aging processes, accelerated by NOM photochemical activity, increase surface oxygen functionality and hydrophilicity, further altering transport. The review underscores the need for systematic studies under environmentally relevant conditions to predict MP fate accurately.

Environmental Chemistry2026DOI: 10.7524/j.issn.0254-6108.2025010607

Multi-media Distribution, Source Apportionment, and Risk Assessment of Polycyclic Aromatic Hydrocarbons in the Forest-Grassland Transition Zone of Inner Mongolia

This study investigated the occurrence, sources, and ecological risks of polycyclic aromatic hydrocarbons (PAHs) in soil, litter, and bark samples collected from the forest-grassland transition zone of Inner Mongolia. A total of 12 PAHs were detected in soil, with concentrations ranging from 34.9 to 465.3 ng·g⁻¹ (mean 168.8 ng·g⁻¹), predominantly 3–5 ring compounds. Litter contained 14 PAHs at concentrations between 106.4 and 2262.5 ng·g⁻¹ (mean 465.1 ng·g⁻¹), dominated by 3- and 4-ring PAHs. Both living and dead bark exhibited 14 PAHs, with concentration ranges of 119.2–240.0 ng·g⁻¹ and 123.3–241.6 ng·g⁻¹, respectively, mainly composed of 4-ring PAHs. Spearman correlation analysis revealed no significant correlations among PAH concentrations across the three media (P > 0.05). Source apportionment using diagnostic ratios and principal component analysis indicated that soil PAHs primarily originated from biomass, coal, and gasoline combustion; litter PAHs from petroleum volatilization and coal/natural gas combustion; and bark PAHs from petroleum volatilization and fossil fuel combustion, with high-molecular-weight PAHs dominating. Ecological risk assessment using the risk quotient (RQ) method showed that soil PAHs posed low overall ecological risk, though certain individual PAHs exhibited higher risk. The toxic equivalent (TEQ) method indicated that dead bark was the primary accumulation medium with high carcinogenic contribution, posing elevated ecological risk. Although litter and living bark had lower PAH concentrations, their long-term accumulation effects warrant attention. These findings provide crucial scientific evidence for understanding the environmental behavior and potential risks of PAHs in cold, high-latitude regions of northern China.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-3983-4

Electrocaloric Devices for Solid-State Refrigeration: Design Strategies and Applications

Refrigeration is essential for modern society, supporting applications from household appliances and industrial manufacturing to microelectronics and biopharmaceutical cold chains. Conventional refrigeration technologies are constrained by environmental impact and low energy efficiency, emphasizing the importance of developing sustainable alternatives. Solid-state caloric refrigeration, particularly electrocaloric (EC) devices, offers a promising route owing to their high cooling efficiency, rapid electric-field-driven response, and potential for miniaturization. Significant progress has been achieved in various EC device configurations. However, EC devices still face challenges in achieving large temperature spans, high cooling power, and effective integration for specific applications. This review systematically summarizes these developments, focusing on device design and performance enhancement. It elucidates the fundamental and shared design strategies, classifies EC devices into fluid-based heat-transfer type, solid-based heat-transfer type, and thermal-resistance-modulated heat-switch architectures, and analyzes representative device structures, performance metrics, and application scenarios. Finally, energy-recovery strategies and future optimization directions toward more efficient EC systems are discussed. This work provides a comprehensive reference for the design innovation and practical implementation of EC-based solid-state refrigeration technologies.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-3982-6

TWEAK-Conjugated Selenoviologen as a Novel Photosensitizer for Selective Wound Accumulation and Synergistic Healing of Drug-Resistant Bacterial Infections

Skin wounds are refractory due to antibiotic-resistant bacterial infection. Although photodynamic therapy (PDT) offers noninvasiveness, high efficiency, and no drug resistance, its therapeutic effect is constrained by the complex structure of wound tissue and diffuse drug distribution. The proinflammatory cytokine tumor necrosis factor-like weak inducer of apoptosis (TWEAK) regulates tissue repair by engaging its receptor Fn14, which is highly expressed in wounds. In this study, we developed a novel photosensitizer, the selenoviologen-TWEAK conjugate (SeV-Tp), to enhance selective enrichment and synergistically promote wound healing. In vitro analyses demonstrated that SeV-Tp, under visible light, generated high levels of reactive oxygen species, resulting in potent antibacterial activity against both Gram-positive and Gram-negative bacteria. Notably, SeV-Tp selectively bound to Fn14 and amplified fibroblast activation via photodynamic cooperation. In a mouse model of antibiotic-resistant Pseudomonas aeruginosa-infected wound, SeV-Tp accelerated healing by reducing bacterial burden, modulating the immune microenvironment, promoting collagen deposition, and stimulating hair follicle regeneration. Moreover, SeV-Tp preferentially accumulated within wound tissues with minimal adverse effects. SeV-Tp represents a strategy that selectively enriches and harnesses synergistic benefits from both components, positioning SeV-Tp as a promising photosensitizer for the treatment of refractory wounds.

Journal of Environmental Engineering Technology2026DOI: 10.13205/j.hjgc.202608008

Circular-Economy-Oriented Medium-Chain Fatty Acid Production from Organic Wastes via Chain Elongation: Artificial Regulation and Resource-Loop Pathways

Medium-chain fatty acids (MCFAs), including caproate and caprylate, are promising biobased products with high energy density, hydrophobicity, and chemical conversion value, serving as key intermediates linking organic waste valorization to circular economy development. Compared to conventional anaerobic digestion for methane, chain elongation (CE) via reverse β-oxidation (RBO) converts short-chain intermediates (e.g., acetate, lactate, ethanol) into higher-value carboxylic acids, offering a novel route for resource recovery from sewage sludge, food waste, agricultural residues, livestock manure, and high-strength organic wastewater. However, natural mixed-culture CE systems face constraints from substrate composition fluctuations, electron donor competition, methanogenic carbon diversion, insufficient product selectivity, product toxicity, and high separation costs, hindering stable, efficient, and targeted MCFA production. This review systematically summarizes the metabolic mechanisms, artificial regulation strategies, and engineering bottlenecks in CE-based MCFA production, emphasizing directed recovery of carbon and electron resources from organic wastes. Future directions include stable continuous-flow operation, product separation and recovery, techno-economic assessment, and life cycle evaluation. The review aims to provide insights for high-value organic waste utilization and synergistic optimization of carbon and energy recovery.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-4068-2

Unveiling strength-ductility synergy in eutectic high-entropy alloys via directional solidification

Eutectic high-entropy alloys (EHEAs) combine multi-principal-element compositions with regular lamellar microstructures, offering exceptional high-temperature stability and mechanical properties. However, conventional casting yields random solidification microstructures and inhomogeneous phase distributions, constraining strength-ductility synergy. This study employs directional solidification (DS) on Al19Fe20Co20Ni41 EHEA to achieve precise microstructural control, constructing a multi-level lamellar architecture with a herringbone-like alternating arrangement. This tailored microstructure refines interlamellar spacing, eliminates detrimental isolated B2 phases, and promotes slip continuity at interfaces, enhancing coordinated dislocation motion and uniform distribution across multiple slip systems. Consequently, the DS EHEA exhibits superior mechanical properties compared to most reported thermomechanically processed and directionally solidified HEAs. Micro-mechanistic analysis reveals that homogenized geometrically necessary dislocation (GND) density, interface-assisted crack deflection, and multi-stage strain-hardening from sequential dislocation activation collectively contribute to outstanding strength-ductility synergy. This work demonstrates that programming solidification paths enables design of unique multi-level lamellar architectures, serving as intrinsic microstructural composites that optimize dislocation management and crack propagation, offering a novel paradigm for developing ultra-robust EHEAs for extreme service environments.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-4104-4

COFAP: A Universal Framework for COFs Adsorption Prediction through Designed Multi-Modal Extraction and Cross-Modal Synergy

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.