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Verified CAS / Academic Author21 Decoded Studies

Prof. GUO Han

School of Mathematics and Statistics, Northeast Petroleum University, Daqing 163318, China

Research Publications & English Decoded Briefs

Showing 21 publications
Acta Energiae Solaris Sinica2026DOI: 10.19912/j.0254-0096.tynxb.202608_9684

A Method for Heliostat Field Modeling and Effective Energy Flux Density Calculation

This study addresses the computational bottleneck in heliostat field optical efficiency assessment by proposing a reverse projection method for calculating effective energy flux density on heliostat surfaces. The method replaces conventional cosine efficiency and truncation efficiency calculations with an irradiance function, determines shadowing and blocking occurrences, computes single heliostat power, and accumulates total field power. By reordering the summation in the total power integral, the method derives the energy flux density distribution on the receiver surface and, through an alternative reordering, the effective energy flux density distribution on each heliostat. This distribution enables determination of the heliostat shape that maximizes power under given area or other constraints, and rapid evaluation of optical efficiency across different shapes and layouts. Numerical simulations demonstrate that heliostats shaped according to the proposed algorithm require smaller mirror areas to achieve equivalent power output compared to conventional rectangular and polygonal geometries, while maintaining superior stability. The study employs a no-blocking dense layout combining Campo and EB arrangements. Results show that a single irregular heliostat achieves an optical efficiency of 0.8022, significantly exceeding square (0.7372), pentagonal (0.7453), hexagonal (0.7485), heptagonal (0.7491), octagonal (0.7502), and circular (0.7513) configurations. The method also reveals that heliostats closer to the receiver exhibit higher energy flux density, with the field energy density in the northern hemisphere displaying a north-high/south-low and center-high/edge-low pattern, consistent with other modeling approaches.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-026-4436-0

Microwave-Absorbing Materials with Strong Environmental Adaptability for Corrosion Protection, Anti-Icing, and Thermal Management

Microwave-absorbing materials (MAMs) deployed on naval vessels, aerospace vehicles, and critical electronic systems face coupled electromagnetic, marine salt-spray corrosion, and extreme-temperature loads that legacy single-function absorbers cannot withstand. This review consolidates progress on three environmentally adaptive MAM classes: corrosion-protective, anti-icing, and thermal-management absorbers. The electromagnetic loss and impedance-matching fundamentals are first established, then the synergistic mechanisms, design strategies, and characterization protocols for each class are examined against representative material systems and their measured performance. The analysis identifies a shared design logic—multiscale hierarchical architecture, interfacial polarization engineering, and multifunctional phase integration—while distinguishing the divergent protection mechanisms: barrier and passivation effects for corrosion, surface-energy and latent-heat regulation for anti-icing, and phonon–electron transport decoupling for thermal management. Persistent bottlenecks include the trade-off between impedance matching and protective-layer density, the absence of standardized coupled-field test protocols, and the scarcity of long-term salt-spray and thermal-cycling durability data. Future directions are delineated: intelligent self-adaptive absorbers, multiphysics-coupled simulation frameworks, and environmentally benign multifunctional integration. The review provides a theoretical and technical basis for the design, construction, and engineering scale-up of next-generation high-performance absorbers for aerospace, electronic, and marine equipment.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-026-4273-3

Emergent Strain Engineering of Freestanding Oxide Membranes

Freestanding membranes have driven a profound evolution of strain engineering by fundamentally overcoming the substrate clamping effect. This structural degree of freedom enables the introduction of spatially complex, reversible, and giant strain fields into the membranes via mechanical manipulations such as stretching, bending, and interfacial twisting, ultimately facilitating the modulation of diverse physical properties. This review systematically discusses recent experimental and theoretical advances in the field, highlighting the modulation of physical properties via uniaxial/biaxial strain, strain gradients, and oxide twist. These mechanical strain strategies substantially broaden the range of achievable material properties, furthermore provide fundamentally new pathways for realizing unconventional mechanical behaviors, inducing emergent polar topological structures, and exploring correlated electronic states. Finally, this review summarizes current methodologies for implementing emergent strain engineering of oxide membranes, delves into the profound impacts of spatially complex strain on the fundamental physical properties of freestanding oxides, and offers a forward-looking perspective on the tremendous opportunities and challenges in this rapidly evolving field.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-026-4354-9

Hybrid graphene and carbon fiber reinforced composites: Synthesis-structure-property relationships

This review systematically examines the synthesis-structure-property relationships of hybrid graphene and carbon fiber reinforced composites, encompassing polymer, metal, and ceramic matrix systems. The hybridization of graphene with carbon fibers addresses the intrinsic limitations of conventional composites, such as weak interfacial bonding and insufficient multifunctionality. The review consolidates recent advances in fabrication strategies, including electrophoretic deposition, layer-by-layer assembly, and precursor impregnation, which enable controlled graphene distribution and orientation. Critical analyses of mechanical, tribological, electrochemical, and anti-ablation properties reveal that graphene addition significantly enhances interfacial shear strength, thermal stability, and electrical conductivity. For instance, in copper matrix composites, the incorporation of reduced graphene oxide with short carbon fibers improves tribological performance, reducing wear rates under specific load conditions. In ceramic matrix composites, graphene-modified C/C-SiC composites exhibit superior anti-ablation resistance, with mass loss rates reduced by up to 30% at elevated temperatures. Furthermore, graphene-coated carbon fiber electrodes demonstrate high specific capacitance and cycling stability in energy storage applications. The review also addresses challenges such as dispersion uniformity, scalability, and cost-effectiveness, proposing future directions for industrial adoption. By providing a comprehensive framework, this work guides the design of next-generation hybrid composites tailored for aerospace, automotive, and energy storage sectors.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-026-4367-4

Enhanced γ-Ray Detection Performance of Cs3Cu2I5 Single Crystals via Suppression of Second-Phase Formation

Single-crystalline Cs3Cu2I5 has attracted considerable interest owing to its excellent scintillation performance and favorable stability. Nevertheless, second phases induced by peritectic reactions during melt growth give rise to deteriorated scintillation properties and promote crystal cracking. In this work, the effects of non-stoichiometric ratios of raw material (n(CsI)=0.57, 0.62, and 0.63) on the crystallization behavior and scintillation properties were systematically investigated. The results show that the crystal quality is optimal at n(CsI)=0.62, featuring high transparency, absence of macroscopic inclusions, and cracking free, with a PLQY of 79.3%. Temperature-dependent photoluminescence verifies the self-trapped exciton emission mechanism with strong exciton-phonon coupling, giving an exciton binding energy of 473.9 meV and a Huang-Rhys factor S of 79.8. The as-grown crystal exhibits an optimized light yield of 24,380 photons/MeV, an energy resolution of 3.8% for 137Cs (662 keV) γ-rays, a dominant decay time of 957 ns, and excellent linear response in the medium-to-high energy region. Precise regulation of the raw material stoichiometry can effectively suppress the formation of second phases, yielding high-quality Cs3Cu2I5 single crystals whose comprehensive performance demonstrates promising application potential in γ-ray detection.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-026-4199-8

Synthesis, Structure, Properties and Applications of High-Entropy Borides

High-entropy borides (HEBs) represent an emerging class of high-entropy materials that have garnered significant attention as ultra-high-temperature ceramics (UHTCs). By leveraging the high configuration entropy effect, HEBs stabilize single-phase solid solutions, exhibiting a suite of properties unattainable in traditional binary borides. This review systematically consolidates research progress on HEBs, beginning with theoretical predictions and component design via first-principles methods. It then details typical HEB systems and principal synthesis techniques, including arc melting and spark plasma sintering. The core analysis evaluates the outstanding performance of HEBs, emphasizing exceptional mechanical properties such as ultra-high hardness and excellent fracture toughness, alongside high-temperature friction and wear behavior, and oxidation resistance. Finally, the review outlines application prospects in extreme environments like aerospace and cutting tools, while also addressing current challenges. The paper underscores the potential of HEBs to overcome the hardness-toughness trade-off inherent in conventional ceramics, driven by strong metal-boron hybridization. This comprehensive overview positions HEBs as promising candidates for next-generation thermal and mechanical protection systems, with future research directions focusing on optimizing compositions and processing to tailor properties for specific applications.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-3682-6

Axial orbital hybridization enables single-atom Fe-N-C hollow microplates for efficient oxygen reduction

Metal single-atoms with optimized coordination structure on highly accessible substrate can maximize the metal utilization efficiency along with enhancing catalytic activities. Herein, axial nitrogen-coordinated Fe-N5 sites on N-doped carbon (denoted as FeN5@N-C) hollow microplates are fabricated via a unique Fe3+-chelated polydopamine assisted hollowing strategy using ZIF-L microplates as multifunctional templates. Due to the powerful chelating and adhesive ability of polydopamine, this hollow-carbon strategy can be extended to fabricate single-atom Fe-N-C hollow structures with different shapes and encapsulate other transition-metal single atoms (Ni, Co, Mn, and Cu) into the N-doped carbon hollow microplates. The FeN5@N-C hollow microplates exhibit outstanding oxygen reduction reaction (ORR) capability with an impressive half-wave potential of 0.93 V vs. reversible hydrogen electrode and high stability, which can serve as air-cathode catalysts for high-performance Zn-air batteries with high peak power density of 225.3 mW cm−2 and stable cyclability of up to 400 h. Comprehensive analysis and theoretical calculations elucidate that axial nitrogen coordination in Fe-N5 catalytic sites, unlike the planar Fe-N4 configuration, can compete well with the bonding of OH* through additional 3d-2p orbital hybridization, thereby giving moderate bonding strength to enhance the ORR activity.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-3836-8

Interface Engineering of MXenes for Flexible Energy Storage and Harvesting

Flexible energy storage and harvesting devices, as core components of flexible electronic systems, have driven the transformation from external power supply to self-powering and from fixed forms to adaptive configurations, playing a pivotal role in wearable technology and the Internet of Things. MXenes, a class of two-dimensional transition metal carbides, nitrides, and carbonitrides, are promising candidates due to their excellent conductivity, mechanical flexibility, and tunable interfacial characteristics. Specifically, interfacial characteristics—surface energy, surface terminations, and interlayer spacing—decisively influence device performance. This review summarizes the influence of microcosmic interfacial characteristics on macroscopic properties, interfacial regulation strategies, and applications in flexible energy storage and harvesting. It concludes with challenges and perspectives for designing high-performance MXene-based energy devices. Key applications include flexible supercapacitors, batteries, and triboelectric nanogenerators. For instance, pillared Ti3C2 via CTAB pre-pillaring and Sn4+ pillaring regulates interlayer spacing, enhancing ion transport. The review integrates recent advances, such as MXene/nylon scaffolds for dendrite-free zinc anodes and MXene-bonded hard carbon films for sodium/potassium storage, demonstrating improved cycling stability and rate capability. The interfacial engineering strategies discussed provide a roadmap for overcoming stacking issues and achieving high energy density and mechanical robustness.

Environmental Chemistry2026DOI: 10.7524/j.issn.0254-6108.2024121101

Aggregation of Antibiotic Resistance Plasmids under Different Hydrochemical Conditions

The excessive and uncontrolled use of antibiotics inevitably leads to their release into natural environments, accelerating the production, occurrence, and transport of resistant bacteria and resistance genes. Among these, antibiotic resistance plasmids (ARPs) pose a significant public health challenge due to their environmental persistence and ability to spread and amplify within microbial communities. This study used the tetC gene-pUC18 plasmid as a model ARP to investigate aggregation behavior in aqueous environments under varying pH (3–7), ionic strength (0.001–0.1 mol·L−1 NaCl and 0.001–0.05 mol·L−1 CaCl2), and in the presence of different concentrations of natural colloids. Results indicate that at low pH, ARP structure condenses inward and functional groups may protonate, reducing negative charge and overall size. Compared to Na+, Ca2+ forms cationic bridges between negatively charged phosphate diester groups, significantly enhancing aggregation. Natural colloids induce heteroaggregation with ARPs, with aggregate size increasing with colloid concentration. This study provides scientific evidence for elucidating ARP behavior in soil and groundwater, crucial for assessing risks to human health and ecosystems and understanding global circulation mechanisms.

Chinese Journal of Environmental Engineering2026DOI: 10.12030/j.cjee.202508050

Spatial Differentiation of Heavy Metals in a Landfill Site in a High-Altitude Cold Region Driven by Freeze-Thaw Cycles

This study investigated the spatial distribution and ecological risk of heavy metals (As, Cd, Cr, Cu, Ni, Pb, Zn) in soil beneath an informal waste dump in a pastoral area of Baingoin County, Nagqu City, Tibet, a high-altitude cold region with frequent freeze-thaw cycles. A total of 55 soil samples were collected from surface (0 cm), middle (10-30 cm), and deep (50 cm) layers. Single-factor index (Pi), geo-accumulation index (Igeo), Nemerow index (PN), and risk assessment code (RAC) were employed to evaluate contamination levels and potential ecological risks, while Kriging interpolation was used to map spatial distribution. Results showed that average concentrations of all seven heavy metals exceeded local background values. Horizontally, high-concentration zones were mainly located at five points within the dump. Vertically, Cd, Cu, Pb, and Zn were significantly enriched in the surface layer, whereas Ni exhibited higher concentrations in deeper layers, indicating downward migration driven by freeze-thaw processes. All evaluation methods identified Cd as the primary pollutant. Speciation analysis revealed that heavy metals were predominantly in the residual fraction, with Ni having the highest weak-acid-extractable fraction (5.55%), indicating strong mobility and potential biological toxicity. This study fills a gap in systematic research on informal waste dumps in high-altitude ecologically fragile areas and provides a case reference for environmental management and remediation of such sites in cold regions.

Journal of Environmental Engineering Technology2026DOI: 10.13205/j.hjgc.202605004

Systematic Governance Framework for Quality and Efficiency Improvement of Sewage Pipeline Networks in Rainy Cities of Southern China

To address the decline in operational performance of sewage pipeline networks in rainy cities of southern China caused by structural defects, stormwater-sewage cross-connections, and external water intrusion, a systematic governance framework comprising precise investigation, dynamic regulation, graded rehabilitation, and smart operation and maintenance was established. A zoned priority evaluation model was developed with comprehensive problem severity (P) and governance contribution (B) as core indicators, based on which differentiated governance strategies were formulated. Supported by a digital platform, monitoring, assessment, rectification, and verification data were integrated to develop a digital twin system for the pipeline network, and a correlation-based analysis and closed-loop operation and maintenance mechanism linking rainfall, groundwater level, and network hydraulic load was established. A typical urban area in Jiangxi Province was selected as the case study. After implementation, the mean COD concentration of terminal sewage in the study area increased steadily to above 230 mg/L, the average daily external water volume in the dry season decreased by 27.64%, and the sewage collection rate increased to 76%. The results indicate that the proposed framework can effectively support the quality and efficiency improvement of sewage pipeline networks in rainy cities of southern China, and provide a technical reference for similar cities.

Journal of Fuel Chemistry and Technology2026DOI: 10.1016/S1872-5813(26)60672-X

Mechanism of Ce/La/Zr doping on the structure and anti-coking performance of Ni/MgO-MgAl2O4 catalyst

Dry reforming of methane (DRM) converts CH4 and CO2 into syngas, offering a route to mitigate greenhouse gases. Ni-based catalysts suffer from sintering and carbon deposition at high temperatures. This work employs MgO-MgAl2O4 composite supports to regulate Ni loading and introduces Ce, La, and Zr as promoters to investigate their effects on DRM activity, structural stability, and surface oxygen species. Optimal Ni loading of 12.5% yields highest CH4 and CO2 conversions. Promoter introduction slightly suppresses low-temperature activity but substantially modifies support local structure and metal-support interface, improving NiO dispersion and increasing surface oxygen vacancies and active oxygen species (Oβ). These changes enhance CO2 adsorption-activation and suppress carbon deposition. After 20 h DRM, Ce-promoted catalyst shows smallest Ni particle growth (6.23→8.07 nm) and lowest carbon deposition, demonstrating superior stability and anti-coking capability. The study elucidates how Ce, La, and Zr enhance sintering and coking resistance via interfacial electronic modulation and improved oxygen storage/release, guiding rational design of stable Ni-based DRM catalysts.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-4034-3

Active Site Concentration Steers the Reaction Pathway of CO2 Electroreduction

The local concentration and configuration of active sites critically influence the selectivity of CO2 electroreduction, yet constructing well-defined structures to probe this relationship remains challenging. Here, we report a molten salt-assisted strategy to synthesize Ce-Ov-Cu cascade catalysts with tunable configurations and relative concentrations of Cu and Ce-Ov sites. Two distinct geometries were engineered: one with dense Cu sites surrounding Ce-Ov (Cu10CeOx) and another with isolated Cu centers encapsulated by Ce-Ov (CuCe10Ox). These configurations direct key intermediates (*CHO or *COH) toward either C-C coupling or deep hydrogenation, thereby switching product selectivity. CuCe10Ox achieves a CH4 Faradaic efficiency (FE) of 61.7% at -1.6 V vs. RHE, whereas Cu10CeOx favors C2 production with a maximum FE of 61.5% at -1.4 V vs. RHE. Mechanistic studies reveal that locally concentrated Cu sites exhibit strong *CO2 binding affinity, enhancing *CO surface coverage and facilitating *CO-*COH coupling. In contrast, Ce-Ov-rich regions with isolated copper centers supply abundant *H, promoting deep protonation of *CHO toward CH4. This work provides insights into catalyst design, demonstrating that manipulating structural chemistry can guide CO2RR toward targeted products.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-4081-y

Multifunctional mitochondria-targeting energy disruptor for enhancing imaging-guided low-temperature photothermal therapy of melanoma

The evolution of precision medicine has propelled multimodal imaging-guided phototheranostics to the forefront for precise tumor diagnosis and therapy. Low-temperature photothermal therapy (PTT) offers a promising approach for the treatment of melanoma due to its non-invasiveness and minimal damage to normal tissues. However, its efficacy is limited by cancer cell thermal tolerance. To address this, a new type of multifunctional energy disruptor (CAMeO-Q NPs) is developed featuring homologous targeting and mitochondria targeting, and synergistically enhancing low-temperature PTT in melanoma by reversing heat shock protein 90 (Hsp90)-mediated thermal tolerance and blocking mitochondrial adenosine triphosphate (ATP) biosynthesis. The multifunctional energy disruptor enables precise trimodal imaging (fluorescence imaging/FLI, photoacoustic imaging/PAI, and photothermal imaging/PTI) guidance for low-temperature PTT. Comprising a mitochondria-targeting photothermal agent and an Hsp90 inhibitor, CAMeO-Q NPs induce selective mitochondrial damage under 660 nm laser irradiation and downregulate cellular HSP expression by ATP inhibition and Hsp90 inhibitor. This multifunctional energy disruptor provides a novel strategy for enhancing multimodal imaging-guided low-temperature photothermal therapy through combined homologous targeting, mitochondria-targeting, and Hsp90 inhibition.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-026-4150-2

Injectable Hydrogel with Photothermal Antibacterial Properties for Accelerating Infected Wound Healing

Bacterial infection and irregular wound morphology are major challenges in clinical wound management. Injectable hydrogels can conform to irregular wound geometries but often lack antimicrobial activity. Here, we report an injectable hydrogel (HPAu gel) formed by sequentially mixing phenylboronic acid-modified hyaluronic acid (HA-PBA) and chloroauric acid under alkaline conditions. The gel's internal multiple crosslinks enable uniform encapsulation of in situ-generated gold nanoparticles. Hydrogen bonds and phenylboronic acid ester bonds confer self-healing, injectability, and adhesion, allowing effective sealing of irregular cavities. In vitro, the hydrogel exhibits long-lasting photothermal stability and eliminates multiple bacterial strains. In a mouse dorsal full-thickness infected wound model, HPAu gel under near-infrared (NIR) irradiation eradicated Staphylococcus aureus, reduced inflammation (TNF-α fluorescence area significantly lower; IL-10 area 12.88‰ vs <2‰ in Blank), promoted vascular regeneration (CD31 and α-SMA expression increased), and accelerated wound healing. This work presents a promising strategy for treating irregular infected wounds.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-026-4208-8

Boosting the cycling stability of P2-type layered oxide cathodes via a synergistic high sodium and Li/Mg co-doping strategy

Sodium-ion batteries (SIBs) are emerging as a cost-effective alternative to lithium-ion batteries due to the abundance of sodium resources. Among cathode materials, P2-type layered oxides (Na_xTMO_2) offer high ionic conductivity and rate capability but suffer from low initial sodium content and Na+/vacancy ordering, leading to structural degradation and capacity fading. This study proposes a synergistic strategy combining high sodium content with Li/Mg co-doping to enhance the cycling stability of P2-type cathodes. The high sodium content increases the sodium reservoir, reducing the depth of desodiation for a given capacity, while Li/Mg co-doping mitigates Na+/vacancy ordering and stabilizes the crystal structure. The optimized cathode exhibits significantly improved cycling performance, retaining 82.3% of its initial capacity after 500 cycles at 1C, compared to 65.4% for the undoped counterpart. Furthermore, the co-doped material demonstrates enhanced rate capability, delivering 112 mAh/g at 5C, and suppressed phase transitions, as evidenced by in-situ X-ray diffraction. This work provides a rational design pathway for high-performance P2-type cathodes, addressing key bottlenecks in SIB commercialization.

SCIENCE CHINA Materials2025DOI: 10.1007/s40843-025-3366-9

Organic Solar Cells Surpassing 20% Power Conversion Efficiency: Material Innovations, Device Engineering, and Pathways to Flexible Power Suppliers

Organic solar cells (OSCs) have transitioned from <1% initial power conversion efficiency (PCE) to a benchmark exceeding 20% in single-junction and tandem architectures, marking a critical milestone for solution-processable photovoltaics. This review consolidates recent reports (2022–2025) on OSCs with PCE >20%, analyzing key strategies: photoactive material innovation (wide-bandgap polymer donors, narrow-bandgap non-fullerene acceptors), multi-component system construction, deposition protocol optimization, solid/solvent additive engineering, and hole/electron transport layer development. Empirical data from 15 high-impact studies reveal PCEs of 20.0–20.6% in single-junction devices and 20.2–26% in perovskite/organic tandem cells, with interfacial engineering (e.g., yttrium phosphotungstate, carbazole-modified 2PACz, naphthalene diimide interlayers) suppressing bimolecular recombination and enabling scalable large-area fabrication. Operational stability remains a bottleneck: amide-based cathode interlayers achieve 20% PCE with dual-modification mechanisms, while self-assembled monolayers enable hole transport layer-free devices with 18% efficiency and improved stability. The review identifies next-stage challenges: reducing voltage losses (to <0.5 V), scaling deposition uniformity beyond 100 cm², and achieving cost parity with silicon (<$0.30/Wp). These issues are critical for flexible and wearable power suppliers, where mechanical durability (<5% PCE degradation after 1000 bending cycles) and low-temperature processing (<150°C) are mandatory. The analysis provides a roadmap for industrial translation, emphasizing that material–device co-optimization, rather than isolated breakthroughs, will determine commercial viability.

SCIENCE CHINA Materials2025DOI: 10.1007/s40843-025-3441-9

Oxygen-Independent Photoactivation of Kinetically Trapped Persistent Room-Temperature Phosphorescence State for Smart Cold-Chain Monitoring

Stimuli-responsive room-temperature phosphorescence (RTP) materials face challenges in environmental robustness and spatiotemporal controllability, particularly for oxygen- and temperature-sensitive applications. Here, by taking advantage of the high oxygen-permeability barrier of polyvinyl alcohol (PVA) and its photochemical reaction toward certain polyaromatic hydrocarbons, we present phenanthrene- and triphenylene-doped PVA films that exhibit photoactivatable and persistent RTP, with an observable afterglow time >70 s by the naked eye, likely via a kinetically trapped radical pathway. Specifically, such UV-enhanced persistent RTP occurs under both aerobic and anaerobic conditions, contrasting with a regular RTP turn-on mechanism via photo-induced molecular oxygen depletion. The activated RTP state shows temperature-dependent kinetic persistence, i.e., lasting ~5 h at 25°C vs. ~72 h at 4°C, creating irreversible RTP switching from “on” to “off” ideal for cumulative temperature monitoring. The PVA-based ink patterns printed on perishables (e.g., fresh milk bottles) can be used to quantify ambient exposure via RTP decay kinetics (relative intensity loss >84.2% after 3 h at 25°C vs. at 4°C). The current study establishes a kinetic-control strategy for designing programmable RTP materials, addressing unmet needs in smart sensing and quality assurance.

SCIENCE CHINA Materials2025DOI: 10.1007/s40843-025-3333-9

High-efficiency organic solar cells with solvent-insensitive morphology

Organic solar cells (OSCs) have surpassed 20% power conversion efficiency (PCE) through donor/acceptor material optimization and bulk heterojunction (BHJ) morphology control. However, morphology manipulation via solvent selection, additives, and annealing remains system-specific, causing performance variability and impeding scalability. Wang, Li, Gao and co-workers introduce BTP-TO2, a non-fullerene acceptor bearing an oligo(ethylene glycol) side chain, which enables solvent-insensitive morphology. Devices processed from diverse halogenated and non-halogenated solvents achieve consistent PCEs around 19%. Small-angle neutron scattering (SANS) reveals that in deuterated solutions, PM6:BTP-TO2 blends exhibit a fractal dimension with slope ~ -1 in the intermediate q region (0.005–0.1 Å⁻¹) and ~ -4 in the high q region (0.1–0.3 Å⁻¹), indicating a stable, persistent molecular conformation. The design rules: enhance acceptor side-chain/solvent interaction to maintain stable conformation; weaken polymer donor–NFA intermolecular interactions to promote rod-like donor conformation and preferential precipitation, decoupling film formation dynamics from blend morphology. Devices retain >80% of initial efficiency (T80) for over 1200 h under continuous operation, and large-area modules demonstrate consistent performance, supporting industrial scale-up.

SCIENCE CHINA Materials2025DOI: 10.1007/s40843-025-3529-7

Economical Approach to Thermoelectric Cooling: Development of Conductive Polyethylene/Polypyrrole@Constantan Composite Using Extensional Rheological Technology

Thermoelectric cooling offers a fluoride-free alternative to vapor compression refrigeration, yet commercial adoption is constrained by low figures of merit (ZT) and high material costs. This study reports an economical fabrication route for conductive polyethylene/polypyrrole@constantan (PE/[email protected]) composites via a self-created extensional rheological technology. Pyrrole monomers are polymerized on Ni0.49Cu0.59 particles and subsequently dispersed within a polyethylene matrix under an extensional flow field, forming a continuous conductive network. The resulting composite exhibits an electrical conductivity of 1699.8 S cm−2, a thermal conductivity of 13.9 W m−1 K−1, and a ZT of 0.16 at 25 °C. A thermoelectric device integrating PE/Ppy@iron achieved a temperature reduction of 0.4 °C under 30 V/0.3 A direct current. Square-wave pulsed current excitation stabilized the cooling efficiency at its optimum level, while a custom thermal insulation system mitigated parasitic heat loss, collectively yielding a total temperature reduction of 1.6 °C. These results demonstrate a scalable, low-cost pathway for thermoelectric cooling materials, with potential for large-scale commercialization.

SCIENCE CHINA Materials2025DOI: 10.1007/s40843-025-3565-y

Dual-Functional Polyimide-Based Phase Change Composite Aerogels with Latent Heat Storage and Radiative Cooling Capabilities for Energy-Efficient Buildings

Building heating and cooling account for 60% of operational energy consumption, and conventional radiative coolers suffer from thermal accumulation and high-temperature damage under continuous solar irradiance. This work reports a dual-functional polyimide (PI)-based phase change composite aerogel that integrates latent heat storage with radiative cooling. Carbonized PI fibers (CPIF) were fabricated via electrospinning, dispersed in polyamic acid aqueous solution, and freeze-dried followed by thermal imidization to yield CPIF/PI aerogels (CPs). Vacuum impregnation with molten polyethylene glycol (PEG) produced CPIF/PI phase change materials (CPPCMs), which were surface-coated with boron nitride (BN) to obtain shape-stable BN@CPPCMs. CPIF enhances thermal conductivity and, through compatibility with the PI matrix, improves structural stability. The BN coating raises solar reflectivity, suppressing operational temperature rise. The composite prevents single-function radiative coolers from thermal accumulation and high-temperature damage, achieving high enthalpy efficiency and effective temperature regulation. The protocol addresses the bottleneck of insufficient indoor temperature regulation in energy-efficient buildings by combining solar-thermal conversion and storage with passive radiative cooling in a single shape-stable architecture.