SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4263-3
Monolayer black phosphorus (phosphorene) exhibits a direct bandgap and strong in-plane anisotropy, making it a promising candidate for near-infrared (NIR) optoelectronic devices. However, the precise modulation of its excitonic emission via anisotropic strain remains insufficiently understood, particularly regarding the contrasting strain responses of phosphorene versus transition metal dichalcogenides (TMDs). Here, we combine experimental characterization with tight-binding (TB) modeling to elucidate the strain-dependent bandgap evolution in phosphorene. Using a four-band TB model, we derive the bandgap at the Γ point as E_g^BP = 4t1 + 2t2 + 4t3 + 2t5, with hopping parameters t1 = -1.220 eV, t2 = 3.665 eV, t3 = -0.205 eV, t4 = -0.105 eV, and t5 = -0.055 eV. Under tensile strain along the zigzag (ZZ) direction, the interatomic distance associated with t1 increases, reducing the magnitude of |t1|. Since t1 is negative, the bandgap increases, contrary to the behavior of monolayer MoS2, where tensile strain decreases the bandgap due to positive hopping parameters t11, t22, and t12. This anisotropic strain response enables selective tuning of NIR exciton emission. Our findings provide a quantitative framework for strain engineering in phosphorene-based NIR devices, highlighting the critical role of hopping parameter signs in determining bandgap modulation.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4424-5
Covalent organic frameworks (COFs) are crystalline organic porous materials whose atomically precise structures underpin their functional applications. However, atomic-level structural information remains unavailable for most reported COFs, hampering rational design and structure-function studies. For two-dimensional (2D) COFs, synthesizing high-quality single crystals is challenging, and the crystallization mechanism makes it difficult to anticipate stacking arrangements. Lacking direct evidence, researchers often assume AA stacking for [4+4] COFs in powder X-ray diffraction (PXRD) fitting, an assumption now questioned. Here, Zhang et al. report the controlled synthesis of single-crystal 2D binodal COFs via a topological derivation strategy. Using 3D electron diffraction at resolutions of 0.90–1.02 Å, they solved the structures of five COFs (NKCOF-88 to -92) derived from a parent sql framework. The four-connected benzene-core monomers were substituted with extended monomers (pyrene or tetraphenylethylene), decomposable into two three-connected nodes, yielding pseudo-bex and pseudo-hcb networks. Single-crystal analysis revealed that the in-plane chain configuration is determined by imine bond orientation, with cis+cis or trans+trans alignments giving planar layers, while mixed alignments produce undulated layers. Crucially, all five COFs exhibit inclined staggered AB stacking, stabilized by edge-to-face π–π interactions, contradicting the assumed AA stacking. This work provides the first single-crystal evidence of non-AA stacking in [4+4] COFs and establishes a correlation between linkage conformation and layer geometry. The topology-derived method offers a generalizable route to binodal COFs with predefined connectivity, facilitating the fabrication of high-quality single crystals and enabling reticular chemistry to shift from simulated models to real structures.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3582-9
Perovskite quantum dots (PQDs) hold great potential for brain-like neuromorphic computing. However, the development of PQDs-based synaptic devices is hindered by interfacial defects and limited stability. Here, we demonstrate a high-performance Cs2AgBiBr6 QDs/organic single crystal heterojunction synaptic device, fabricated via a novel space-confined vertical growth technique combined with a polymer-free transfer process. Vertically grown organic single crystals enable superior carrier mobility and facilitate the formation of low-defect interfaces with PQDs. The heterojunction exhibits remarkable photosensitivity (7.22 × 10^5 at 425 nm) and detectivity (2.15 × 10^15 Jones), owing to the strong optical absorption of PQDs coupled with the superior charge transport characteristics of organic single crystals. Notably, the device achieves dual-functional light adaptation, emulating synaptic behaviour under blue light while exhibiting photo-switching under green/red light. This unique capability enables smart blue-light hazard protection. This work not only provides a versatile platform for high-performance PQDs-based synaptic devices but also advances the development of brain-inspired neuromorphic systems for next-generation computing and intelligent sensing.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3600-1
Two-dimensional planar pentagonal crystals, long pursued for their geometrically frustrated lattice configurations and emergent quantum phenomena, have remained challenging to realize due to the intrinsic incompatibility of regular pentagons with Euclidean tiling. Here, we unveil 37 dynamically stable binary planar pentagonal monolayers through high-throughput computational screening of 1470 stoichiometric candidates. These materials exhibit room-temperature magnetism, including ferromagnetic (Curie temperature up to 521 K), antiferromagnetic (Néel temperature up to 761 K), and altermagnetic (Néel temperature = 984 K) ground states, alongside unprecedented electronic states: Dirac semimetals, Dirac half-metal, nodal-loop semimetal, nodal-loop half-metal, and altermagnetic semiconductors (Mn4N2) with giant spin splitting (0.78 eV). The latter achieves pure spin-polarized transport windows (−0.04 to 0.36 eV) and strain-tunable valley splitting (18.2 meV under 4% uniaxial strain). Intrinsic type-II multiferroicity emerges in Fe4C2 and Mn4C2, featuring in-plane electric polarization (1.4 and 1.6 pC/m), ferroelasticity (0.8% and 1.2% reversible strain), and reversal chirality. Topological band analysis identifies chiral edge states in Dirac semimetal pentagons, alongside a magnetic topological insulator with Chern number |C| = 2 in Mo2S4 and W2Te4. Temperature-driven structural transitions in Os2S4 and Tc2S4 from pentagonal to Lieb lattices accompany topological state switching and metal-to-semiconductor transitions. This work establishes pentagonal lattices as a platform for symmetry-driven multifunctionality, bridging geometric frustration with applications in spintronics, nanoelectronics, and quantum devices.
New Carbon Materials•2026•DOI: 10.1016/S1872-5805(26)61075-X
The proliferation of electronic devices has intensified electromagnetic radiation pollution, necessitating advanced microwave absorption materials. This study presents the electrospinning fabrication of FeNiCo/carbon nanofiber (FeNiCo/CNF) composites with exceptional microwave absorption properties. The FeNiCo/CNFs achieved a minimum reflection loss (RLmin) of −55.5 dB at 14.24 GHz with an ultrathin matching thickness of only 1.6 mm. Microstructural analysis and electromagnetic parameter testing revealed that the superior absorption stems from the synergistic interaction between the carbon nanofiber network and FeNiCo alloy nanoparticles, which promotes multiple reflections and efficient energy dissipation. The precise control of coercivity and permeability via systematic modulation of magnetic metal composition enabled enhanced impedance matching and optimized magnetic-dielectric synergy. Furthermore, radar cross-section (RCS) simulations confirmed the material's capability to significantly reduce RCS values across a wide angular range, validating its potential for stealth technology applications. This work introduces a cost-effective and sustainable approach for developing ultralight, high-performance microwave absorbers, addressing the limitations of conventional materials such as high density and poor stability.
New Carbon Materials•2026•DOI: 10.1016/S1872-5805(26)61104-3
Lithium/fluorinated carbon (Li/CFx) batteries are among the most promising high-energy-density primary batteries, yet substantial heat generation during discharge poses safety concerns, particularly for high-mass-loaded pouch cells. This study systematically investigates the effects of fluorination temperature on the structure and kinetics of fluorinated porous carbon (FPC) cathodes and on heat generation in Ah-level Li/FPC pouch cells. FPC samples with varying degrees of fluorination were synthesized by adjusting fluorination temperature, which influenced not only the F/C ratio but also the C–F bonding configuration, pore structure, and electronic transport capability. Pouch cells employing more highly fluorinated cathodes generated the most heat during discharge, with heat generation exhibiting clear stage dependence, predominantly in the 0–20% depth of discharge (DOD) range. Post-discharge structural characterization and kinetic analysis revealed that highly fluorinated FPC cathodes (FPC-250) undergo more concentrated LiF accumulation, leading to higher charge-transfer resistance, stronger polarization, lower Li+ diffusivity, and higher nucleation overpotential. These factors collectively intensify early-stage heat generation. The study establishes a correlation between fluorination temperature and cathode structure, discharge-product evolution, discharge kinetics, and heat generation, demonstrating that regulating fluorination temperature is an effective strategy for improving the thermal safety of Li/CFx batteries.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3964-5
The escalating demand for personalized thermal-moisture comfort, coupled with the high energy consumption of conventional heating and cooling systems and the imperative for low-carbon energy conservation, has driven the development of shape memory smart fabrics that respond to environmental changes. However, existing shape memory thermal-moisture management fabrics suffer from excessively high response temperatures, inadequate response performance, and suboptimal thermal-moisture management. In this work, a dual-network shape memory polymer (SMP) was synthesized, and its shape memory transition temperature was tuned to align with the human thermal comfort range. The polymer was processed into fibers and subsequently into twisted-coiled artificial muscles to enhance reversible strain. Woven with wool into a plain fabric, the resulting textile exhibits adaptive thermal-moisture management, achieving a warp reversible strain of up to 17.5%. At elevated temperatures, the fabric contracts, exhibiting an air permeability of 1546 mm/s and thermal conductivity of 0.0518 W/(m·K); at lower temperatures, it elongates, with air permeability of 1322 mm/s and thermal conductivity of 0.0426 W/(m·K), thereby realizing 'warm when cool and cool when hot' functionality. Compared with commercial wool fabrics, this smart fabric lowers the skin microenvironment temperature by 1.5 °C and offers an energy savings potential of approximately 222.58 MJ/m² per year in capital cities such as Beijing. This work provides a novel technical pathway and design approach for future personalized comfort and low-carbon, energy-saving textiles.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4059-3
Deuterium (D2) is indispensable for isotope tracing, neutron scattering, and fusion reactions, yet its separation from hydrogen (H2) remains challenging due to their nearly identical physicochemical properties. Adsorptive separation exploiting the kinetic quantum sieving (KQS) effect at cryogenic temperatures offers a promising route, but demands precise pore engineering. Here, we report a biomass-derived carbon molecular sieve that permits rapid D2 transport while imposing a significant diffusion barrier for H2, enabling effective separation from D2/H2 mixtures. The molecular sieving micropores are generated by transforming cellulose components into slit-type carbon micropores, with lignin acting as a pore-size modifier. At 77 K, the diffusion rate of D2 is 1.8 times that of H2, leading to a D2 concentration in the recovered gas approximately 10% higher than that achieved with conventional microporous carbons. Aspen adsorption simulations demonstrate that D2 can be enriched to 90.1% from a 1.0% D2/H2 mixture within 12 successive cycles following a two-bed cryogenic pressure swing adsorption process. These findings advance the development of effective adsorbents for kinetic D2/H2 separation, offering a sustainable, low-cost route to deuterium enrichment.
Journal of Fuel Chemistry and Technology•2026•DOI: 10.1016/S1872-5813(26)60668-8
A series of Co-based molecular sieve catalysts with varying Si/Al ratios was synthesized via impregnation. Microstructural properties of Co active sites were characterized by XRD, TEM, Raman, H2-TPR, Py-FTIR, and XPS. Results indicate that surface Co species predominantly exist as CoOx nanoclusters and isolated Co2+, with the latter exhibiting superior N2O decomposition activity. Decreasing the Si/Al ratio of the MFI zeolite promotes the formation of isolated Co2+ active sites, thereby enhancing catalytic performance. Compared to Co/S-1 (pure silica support), the Co/HZ60 catalyst (low Si/Al ratio ZSM-5) lowers the temperature for complete N2O decomposition by 80 °C and demonstrates excellent resistance to O2 and NO. The strong interaction between the zeolite framework and Co2+ inhibits oxidation to Co3+, improving N2O adsorption and activation. This work provides a rational design strategy for efficient and stable Co-based catalysts for N2O abatement in industrial tail gases.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4229-6
The escalating retirement of lithium-ion batteries (LIBs) necessitates efficient recycling technologies to recover cathode materials, particularly lithium iron phosphate (LFP), which dominates the traction battery market. Conventional pyrometallurgical and hydrometallurgical methods are energy-intensive and environmentally burdensome. Here, we report a fluorine doping-assisted direct regeneration strategy for spent LFP (SLFP) cathodes, yielding a regenerated LFP-F (RLFP-F) with a hybrid structure of ordered crystalline and disordered domains. Fluorine doping reduces the Li+ diffusion energy barrier, as evidenced by density functional theory calculations, and strengthens Fe–O bonding, suppressing Fe migration and anti-site defect formation. The O 2p band center shifts downward, increasing the Fe 3d–O 2p energy separation from 3.23 eV in pristine LFP to 3.46 eV in RLFP-F, enhancing structural stability and electronic conductivity. Electrochemical tests demonstrate that RLFP-F delivers a high-rate capability and excellent cycling stability. Life-cycle assessment reveals that direct regeneration consumes only 9.986 MJ kg−1 and emits 0.324 kg CO2-equivalent per kg of cell, significantly outperforming pyrometallurgy and hydrometallurgy. Economic analysis based on 2025 Chinese market prices indicates a net profit of $397.15 per ton of SLFP battery recycling, attributed to the closed-loop cathode-to-cathode design. This work provides a sustainable and economically viable route for upcycling spent LFP batteries.