Physics

The development of efficient catalysts for chlorinated volatile organic compound (CVOC) abatement remains challenging due to insufficient low-temperature activity, chlorine poisoning susceptibility, and toxic byproduct formation. This study addresses these limitations through rational design of Cr-Zr codoped ceria catalysts for efficient, stable, and low-toxic degradation of chlorobenzene (CB). The optimized (CeCr)₃Zr₁ catalyst demonstrates exceptional performance, maintaining >90% CB conversion over 24 h at 240 °C with minimal polychlorinated byproducts. Structure-performance mechanistic investigations reveal that Cr-Zr doping modulates Ce-O bond strength and generates high-density oxygen vacancies, enhancing lattice oxygen mobility and reactive oxygen species generation for deep oxidation. Concurrent Zr incorporation introduces Brønsted acid sites that promote HCl formation via proton-assisted Cl removal, effectively suppressing electrophilic chlorination of aromatic intermediates. These improvements of dual oxygen-chlorine channels reduce the occurrence of electrophilic chlorination reactions in intermediate products, thereby inhibiting the formation of polychlorinated byproducts, making it more promising for industrial applications.

Triboelectric nanogenerators (TENGs) have emerged as powerful tools in wearable electronics, allowing us to harness electricity generated from biomechanical forces using a miniaturized, biocompatible platform. A variety of commercially available polymers with different dielectric properties are typically used for TENGs; however, it is still a significant challenge to precisely and systematically control the degree of triboelectric properties. Herein, a polysuccinimide (PSI) with a controlled degree of perfluorination ("PF-PSI") is developed and implemented for TENG applications. Since PSI consists of a series of succinimidyl ring moieties capable of nucleophilic ring-opening reactions with amine-based molecules under ambient conditions, PF-PSI can be conveniently synthesized by direct conjugation with perfluoroalkylamines. The triboelectric properties of PF-PSI can be fine-tuned over a wide range by controlling the degree of perfluorination via the feed molar ratio and type of perfluoroalkyl amine, with a triboelectric potential of 9-50 V and power density of 0.06-55 μW cm^-2. A nanocomposite film infused with PF-PSI nanofibers, demonstrating enhanced mechanical properties, is developed and explored as a TENG to provide electrical stimulation (ES) to induce tissue regeneration. Up to 85% wound closure is achieved in 9 days with ES from the PF-PSI TENG, effectively demonstrating its therapeutic potential.

Aerogels, as highly efficient thermal insulation materials, exhibit significant potential for applications in building exterior insulation, power battery thermal protection, and aerospace thermal management. However, conventional polymer aerogels possess inherent limitations in thermal insulation performance, mechanical compressive strength, and flame-retardant safety, which impede their widespread engineering adoption. Herein, we propose a synergistic fabrication strategy integrating directional freezing and viscosity modulation. By precisely regulating the temperature gradient and incorporating layered double hydroxides (ZnMgAl-LDH) to tune the viscosity of hydrogel precursors, we enhanced the viscous resistance during ice crystal growth, thereby refining ice crystal dimensions. A honeycomb-like ZnMgAl-LDH/chitosan (CS) inorganic-organic hybrid aerogel with tunable pore size distribution was successfully constructed. The superlattice interface of ZnMgAl-LDH and the organic-inorganic hybrid interface synergistically reinforce phonon scattering (covering both long and short wavelengths), effectively suppressing solid thermal conduction and significantly improving the aerogel's thermal insulation performance. Compared with pure CS aerogel, the hybrid aerogel with optimized pore size displays a lower thermal conductivity (0.03735-0.03936 W/(m·K)) and reduces the surface temperature by 6.9 °C under identical conditions. Moreover, the honeycomb microstructure endows the hybrid aerogel with excellent compressive resilience, retaining 72.4% stress after 50 compression cycles and achieving a compressive modulus 9 times higher than that of pure CS aerogel. Its flame-retardant performance is remarkably enhanced, with the limiting oxygen index (LOI) increasing from 21.5% to 41.4% (meeting high flame-retardant standards) and the peak heat release rate (PHRR) decreasing by 74.9%. Additionally, the hybrid aerogel exhibits superior hydrophobicity and environmental durability, highlighting its great potential for practical engineering applications.

Androgenetic alopecia (AGA) is a common hair disorder in which limited follicular drug delivery and an inflammatory and oxidative follicular microenvironment reduce topical efficacy. Herein, we developed a fast-dissolving microneedle (MN) patch of chondroitin sulfate and carboxymethyl chitosan for localized codelivery of <i>Platycladus orientalis</i> leaf-derived extracellular vesicles (PO-EVs) and minoxidil nanoparticles (MXD NPs). PO-EVs were separated and characterized as nanoscale vesicles and were shown to possess antioxidant, anti-inflammatory, and pro-angiogenic activities relevant to hair follicle maintenance. MXD NPs were prepared by thin-film hydration to improve the minoxidil solubility and local retention. Both were loaded into microneedles with sufficient mechanical strength that could dissolve rapidly in the skin. In a mouse model of androgenic alopecia, repeated dual-loaded MN treatment accelerated the telogen-to-anagen transition, increased hair-covered area and shaft thickness, and restored follicular morphology. Mechanistic studies showed that hair follicle stem cells were activated and proliferated, perifollicular oxidative stress and inflammation were reduced, and microvessel density around hair follicles was increased. No evident skin irritation or systemic toxicity was observed. This MN codelivery strategy improves hair regrowth by combining efficient minoxidil delivery with PO-EV-mediated microenvironment restoration and may be extended to other inflammatory/oxidative skin disorders impairing regeneration.

Accurate pulse-resolved detection of ionizing radiation at megahertz frequencies is essential for applications such as quality assurance in ultrahigh-dose-rate radiotherapy and low-dose X-ray monitoring. Conventional scintillator-based detectors employ bulky single crystals, such as lutetium-yttrium oxyorthosilicate (LYSO), which limit their flexibility and integrability. Furthermore, many perovskite scintillators exhibit afterglow, which leads to signal pile-up under high-flux conditions. To address these challenges, we developed thin polymer composite scintillator films comprising LYSO and (PEA)₂PbBr₄. These films retained the materials' intrinsic decay times (∼37 and ∼6 ns, respectively) while enhancing signal output through the optical scattering of scintillation photons within the inhomogeneous polymer matrix. When coupled with silicon photomultipliers and a field-programmable gate array (FPGA)-based digital counter, these films enabled rapid real-time detection across a broad frequency range. Specifically, the LYSO/PMMA composite detected intense signals up to 2 MHz (500 ns spacing), whereas the (PEA)₂PbBr₄/PMMA composite, with an amplification stage, enabled accurate pulse counting up to 5 MHz (200 ns spacing). With a dead time of ∼20 ns, the system resolved nanosecond-spaced pulses without pile-up, enabling reliable pulse-by-pulse readout from a few counts per second to multimegahertz bursts. These results demonstrate that inhomogeneous composite scintillator films, when integrated with FPGA-based digital processing, provide a compact and scalable pulse counter for high-frequency radiation detection, effectively addressing the limitations of conventional bulky crystal detectors.

Ferroelectric materials offer promising prospects for explosive energy conversion applications owing to their capability to deliver extremely high pulsed power. Unfortunately, the disadvantage of polarization temperature stability especially under a harsh environment poses a significant challenge to application. In this work, we report a 0.95PbZrO₃-0.05Ba(Mg_1/3Nb_2/3)O₃ ferroelectric ceramic that simultaneously exhibits a high remnant polarization (<i>P</i>_r) of ∼35.3 μC/cm² and outstanding polarization temperature stability (i.e., less than 5.1% in a large temperature range from 30 °C to 110 °C). <i>In-situ</i> structural analyses, designed to elucidate the physical mechanisms underlying <i>P</i>_r temperature stability, reveal that ultrahigh temperature stability is due to a stable single rhombohedral phase with an ordered lattice structure, in accordance with a stable oxygen octahedron tilt up to the Curie temperature (∼200 °C). Finally, the pressure-driven ferroelectric-antiferroelectric phase transition depolarization behaviors under hydrostatic pressure and shock compression were achieved from an application perspective. The proposed composition of 0.95PbZrO₃-0.05Ba(Mg_1/3Nb_2/3)O₃ provides not only a promising material for energy harvesting and energy conversion applications, but also a paradigm for the design of other ferroelectric materials with ultrahigh polarization temperature stability.

Periprosthetic joint infection (PJI) and aseptic loosening remain the leading causes of arthroplasty failure, yet existing antimicrobial coatings suffer from limited durability and poor osteointegration. Here, we report a thermo-bioactivated nanohybrid coating (Ti-AQR) that integrates photothermal conversion with bioactive functionalities to achieve combined antibacterial and osteogenic modulation. Ti-AQR could provide stable and durable near-infrared (NIR)-induced mild photothermal performance by Au NRs, a typical photothermal agent, while a chitosan derivative (QTR) with quaternary ammonium groups and RGD motifs delivered both bactericidal and osteoinductive functions, which were promoted by the mild photothermal effect. Under mild photothermal stimulation, the effect of bacterial membrane disruption by the alkyl chains in quaternary ammonium groups was amplified by mild heat, lowering the temperature threshold for effective bacterial killing. Concurrently, mesenchymal stem cell adhesion, osteogenic differentiation, and matrix mineralization were enhanced by the RGD motifs of Ti-AQR combined with subhyperthermic heat. Ti-AQR eradicated >99.9% of <i>Staphylococcus aureus</i> and >97% of <i>Escherichia coli</i> through combined heat-assisted contact killing, while markedly upregulating osteogenic markers, alkaline phosphatase activity, and calcification. Mechanistically, the mild photothermal effect of Ti-AQR activated the MAPK pathway and upregulated heat shock protein-related genes. In animal experiments, Ti-AQR implants simultaneously prevented early-stage infection and significantly improved bone-implant integration. This thermo-induced interfacial synergy establishes a versatile strategy for functionalization of orthopedic implants, offering dynamic, controllable, and biocompatible solutions against both infection and loosening.

Conventional chemiresistive sensors based on metal oxide semiconductors offer high sensitivity, fast response, and low cost. However, the requirement for high-temperature operation is a major issue. Recently, conductive π-conjugated coordination nanosheets composed of metal ions and π-conjugated planar ligands have attracted attention as active materials for chemiresistive sensors operating at room temperature (RT). However, their tendency toward multilayer formation, driven by strong interlayer interactions, impedes access to metal complexes (active sites), thereby reducing their performance. In this study, we synthesized a composite (NiHATT/CNT) consisting of a coordination nanosheet (composed of nickel ions and the triptycene-based three-branched ligand, 2,3,6,7,14,15-hexaaminotriptycene (HATT)) and a carbon nanotube (CNT). We evaluated the humidity response of the chemiresistive sensors using NiHATT/CNT as the active material. The introduction of the triptycene skeleton allowed the square-planar metal complexes to form perpendicular to the two-dimensional surface, thereby allowing analytes to easily access the active sites. Consequently, the NiHATT/CNT chemiresistive sensor exhibited a significantly greater response than the sensor using an active material consisting of a conventional coordination nanosheet with a planar π-conjugated ligand. This demonstrates that the chemical design that provides high accessibility to the metal complexes in NiHATT by introducing a triptycene skeleton enhances the sensing performance of the NiHATT/CNT composite.

Rhombohedral hafnia-based ferroelectrics promise low-coercive, scalable nonvolatile memories, yet their realization has traditionally relied on complex cation intercalation or external stress. Here, we demonstrate a possible intrinsic route to the rhombohedral (<i>R3</i>) phase in Hf_1-<i>x</i>Zr_<i>x</i>O₂ through symmetry breaking of the parent fluorite lattice. First-principles calculations under <i>R3</i> symmetry-constrained equation-of-state conditions show that the 12-atom fluorite-derived configuration, at equiatomic composition (<i>x</i> = 0.5), stabilizes an intrinsically polar <i>R3</i> ground state with spontaneous polarization <i>P</i>_<i>s</i> = 44.9 μC cm^-2, dielectric permittivity <i>ε</i>_<i>r</i> = 51.3, an ultralow switching barrier of 27.8 meV f.u^.-1, and a coercive field of 0.46 MV cm^-1. Distinct from orthorhombic <i>Pca2</i>_<i>1</i>, the <i>R3</i> structure shows nonmonotonic dielectric behavior, revealing a symmetry-renormalized polarization mechanism beyond conventional Vegard-type ferroelectricity. Moreover, the <i>R3</i> phase stabilizes at reduced thickness, with low built-in potential at proper electrodes preserving its low coercive field. Experiments using fast Fourier transform and geometric-phase analysis validate these predictions, and <i>R3</i>-phase-dominant Hf_1-<i>x</i>Zr_<i>x</i>O₂ capacitors exhibit comparably low coercive fields (0.65 MV cm^-1) and enhanced dielectric permittivity <i>ε</i>_<i>r</i> = 39.1.

Laser initiation offers a safer and more controllable alternative to conventional initiation methods, with laser-responsive materials serving as the fundamental platform for such functional conversion. However, existing laser-responsive energetic compounds often rely on heavy metals and suffer from poor safety profiles, significantly limiting their practical deployment. The development of metal-free laser-responsive materials remains largely unexplored. This study introduces a design strategy that enables the construction and transformation of laser-responsive functions in metal-free energetic ionic salts (EISs) through the synergistic regulation of their oxygen balance via a fused-ring scaffold and guest ions. Following this strategy, a metal-free EIS (ES-1) was synthesized from a [5,1-<i>c</i>][1,2,4]pyrazolotriazine ring and a ClO₄^- anion. Subsequent transformations yielded ES-2 via guest anion exchange (ClO₄^- to NO₃^-) and ES-3 through functionalization. The distinct crystal packing, thermal stability, and energetic properties of ES-1, ES-2, and ES-3, as determined by X-ray diffraction and DSC-TG, validate the viability of this component-level functional tuning approach. Rapid laser-initiation tests and high-speed photography confirmed that ES-1 undergoes a deflagration-to-detonation transition (DDT) under 980 nm near-infrared laser irradiation, with a delay time of 185 ms. In contrast, ES-2 exhibited excellent moisture resistance but negligible laser sensitivity, whereas ES-3 displayed pronounced hygroscopicity due to an excessive proportion of oxygen-related contacts, which effectively masked its intrinsic laser responsiveness. These results uncover structure-property relationships governed by scaffold and guest regulation, and underscore the critical role of oxygen balance in regulating photoresponsive activity, energy output, and environmental stability. This work provides a practical framework for designing next-generation, environmentally friendly, metal-free laser initiators.

A three-dimensional/two-dimensional (3D/2D) heterojunction interface is well-known for reducing surface recombination in perovskite solar cells. The effectiveness of 3D/2D interfaces has been particularly highlighted in standard (n-i-p) structures. However, their use in inverted (p-i-n) structures is less common due to limitations on the thickness of the 2D phase, which is essential for efficient electron extraction. In this study, we investigate whether 3<i>D</i>/2D dimensional engineering is beneficial in inverted architecture devices by introducing the bulky organic cation 4-chlorophenethylammonium iodide (Cl-PEAI) to triple cation Cs_0.05(MA_0.17FA_0.83)_0.95Pb(I_0.9Br_0.1)₃ perovskite films using two different deposition methods: as a separate interlayer on top of the fully formed 3D perovskite and via an antisolvent approach during film formation. Through low-energy cathodoluminescence measurements─a highly sensitive method for probing the presence of 2D phases on the surface of 3D layers─we reveal that the interlayer method leads to the formation of 2D domains (<i>n</i> = 1 and <i>n</i> = 2). In contrast, the antisolvent method results in surface and grain boundary passivation without the formation of a detectable separate 2D phase. This observation is further correlated with device performance, where passivation leads to improvement, while 2D phase formation does not. These results highlight the significant impact of the deposition method on the formation of the 2D layer over the 3D perovskite in inverted architectures, revealing that 2D phase formation is not always beneficial for device performance in inverted architecture solar cells.

Achieving low-power, high-mobility organic thin-film transistors requires control over the buried interface between the semiconductor and the dielectric layers. Here, we demonstrate that siloxane-based molecular design provides a powerful means of engineering interfacial compatibility and charge transport. By integrating siloxane-functionalized diketopyrrolopyrrole (DPP) semiconductors with a PDMS-based polyionic liquid (PIL) dielectric, we show that siloxane-siloxane interactions promote enhanced molecular ordering, increased crystal coherence, and improved charge-carrier mobility of the semiconductor. Grazing-incidence wide-angle X-ray scattering and Raman morphological analyses indicate that interfacial interactions drive coherent stacking and reduce the level of disorder at the interface. This interfacial design strategy offers a general approach to tuning interfaces through conjugated polymer/dielectric systems, offering insight into strategies for the development of low-voltage, high-performance organic electronics.

The development of self-powered and sustainable tactile sensors requires scalable materials that integrate electromechanical coupling, environmental compatibility, and high precision. Here, we report a universal electromechanical scaling law governing the voltage-force response in triboelectric nanogenerators (TENGs), established through sustainable SnO₂ integrated polyvinylidene fluoride nanocomposite fibers fabricated via a thermal fiber drawing technique. The fibers exhibit enhanced crystallinity and interfacial polarization, yielding an open-circuit voltage of 37.2 V and a short-circuit current of 36.25 μA, with a corresponding peak power of 32.1 μW (243 mW m^-2) under cyclic mechanical excitation. Beyond performance gains, the extracted force-dependent power law provides a transferable framework to benchmark and compare soft TENG fibers across loading conditions, addressing a major gap in standardized sensitivity metrics. Moreover, the resulting devices demonstrate long-term durability (>16,000 cycles) and exceptional sensitivity in robotic tactile and continuum actuation systems. Integration of the fibers into continuum robotic platforms enabled self-powered tactile sensing and rapid collision detection in free-space and in-pipe scenarios, achieving response times under 25 ms. This study establishes a physics-based framework for soft triboelectric systems, merging sustainable nanomaterials, scalable fiber processing, and universal electromechanical laws, paving the way toward self-powered, ecoconscious robotic and wearable interfaces.

Residues of neonicotinoid insecticides (NEOs) pose serious threats to ecological systems and human health. Conventional nanozyme sensors often suffer from limited catalytic diversity and concentration-dependent response mechanisms, which lead to signal homogenization and cross-concentration misclassification. To address these limitations, we developed a Fe-Cu dual-atom nanozyme (FeCu DAzyme) exhibiting triple-enzyme activities: oxidase (OXD), peroxidase (POD), and laccase (LAC). The synergistic effects between Fe-Cu dual-atom sites significantly enhanced catalytic efficiency, while their specific coordination with NEO functional groups enabled distinct inhibition responses across different concentration levels. Leveraging this property, we constructed a FeCu DAzyme-based colorimetric sensor array that captures real-time inhibition kinetics of OXD/POD/LAC activities, generating unique multidimensional response patterns. Through integration with a machine learning classifier, these patterns enabled accurate pesticide identification independent of absolute concentration values. The sensor array achieved 92.50% accuracy in discriminating five NEO structural analogs across a concentration range of 0.1-50 μg/mL, demonstrating excellent concentration-independent identification capability. Notably, the practical utility of this platform was successfully validated through the high-accuracy identification of NEOs in spiked real-world samples, including lake water and agricultural products. This work established a promising paradigm for rapid NEO identification, which is critical for ensuring agricultural product safety.

Mesenchymal stromal cells (MSCs) hold substantial clinical promise for regenerative and anti-inflammatory therapies due to their inherent capacity for tissue repair and immunomodulation. However, precise understanding and control of how microenvironmental cues influence therapeutic paracrine activities remain poorly defined. Here, we introduce a microfluidic-derived gelatin methacryloyl (GelMA) microsphere system designed for the coencapsulation of MSCs with inflammatory cytokines. This platform allows us to precisely tune the local chemomechanical microenvironment, thereby directly programming the MSC secretome. We demonstrate that the synergy between mechanical signals from a soft matrix and inflammatory biochemical cues (TNF-α and IFN-γ) profoundly enhances the immunomodulatory and regenerative capabilities of encapsulated MSCs. Mechanistic studies reveal that focal adhesion kinase and Yes-associated protein dependent pathways are involved in the mechanosensitive activation of MSCs in the presence of inflammatory factors. In a mouse model of chronic diabetic wounds, treatment with these engineered cell-laden microspheres significantly accelerates wound closure, promotes angiogenesis, and restores immune homeostasis by shifting macrophage polarization from a pro-inflammatory M1 to a pro-regenerative M2 phenotype. Our findings introduce a universal and highly potent mechanomedicine strategy for programming cellular functions, offering an efficient and promising approach for the treatment of chronic inflammatory diseases.

Efficient, low-energy, and byproduct-free strategies for pathogen inactivation and monitoring are urgently needed for water, air, and food safety. Here, we report an integrated nanoelectrochemical platform that combines ultralow-voltage pathogen inactivation with real-time biosensing. A nanoscale Pt/Ti-carbon nanotube (CNT)-Au/Ti three-electrode device is fabricated via high-precision micro- and nanomanufacturing, in which a networked CNT film serves as both the conductive substrate and the electroactive interface. Trace amounts of a hydrophobic ionic liquid are immobilized within the CNT network, forming a stable CNT/ionic liquid/aqueous three-phase interface that promotes efficient single- and multielectron oxygen-reduction pathways and the in situ generation of reactive oxygen species. As a result, complete electrocatalytic inactivation of <i>Escherichia coli</i> (<i>E. coli</i>) and <i>Staphylococcus aureus</i> (<i>S. aureus</i>) is achieved at concentrations up to 10⁹ CFU/mL using an applied potential of only -0.6 V (vs a built-in quasi-reference) and a low current density of 0.1 mA cm^-2. Concurrently, the platform functions as a sensitive bacterial sensor, in which changes in the reduction features of cyclic voltammetry enable quantitative detection of <i>E. coli</i> over a linear range of 0-10⁷ CFU/mL with good reproducibility. This work establishes a general strategy for constructing multifunctional nanoelectrochemical systems and provides a practical route toward integrated pathogen inactivation and monitoring technologies.

In this study, we demonstrate an 8 × 8 synaptic transistor array based on a poly(9,9-di-<i>n</i>-dodecylfluorenyl-2,7-diyl) (PFDD)-wrapped semiconducting single-walled carbon nanotube (s-SWCNT) network. The PFDD polymer wrapping of the SWCNTs offers a synergistic combination for synaptic devices: high selectivity of sorting s-SWCNTs and energetically stable charge-trapping sites along the nanotube surface, enabling controlled conductance modulation. In addition, the simple polymer-SWCNT hybrid structure contributes to highly uniform electrical properties in the array. A reproducible conductance-tuning capability is demonstrated in a PFDD-SWCNT synaptic transistor, resulting in robust synaptic plasticity. Diverse synaptic functions, such as excitatory post-synaptic currents, short- and long-term memory, long-term potentiation (LTP) and depression (LTD), and paired-pulse facilitation, are emulated. The stable dynamic modulation of LTP/LTD in the PFDD-SWCNT synaptic device is validated over 10 000 pulse endurance cycles. Importantly, low nonlinearity values of 2.08 and 2.95 for potentiation and depression, respectively, with an asymmetric ratio of 63.8%, lead to a high recognition accuracy of 90.26% in the handwritten image classification task based on an artificial neural network simulation. The PFDD-SWCNT hybrid structure establishes a robust platform for high-precision and reliable neuromorphic circuitry.

The pursuit of miniaturized spectrometers necessitates device architectures that are both structurally simple and high-performing. This work reports a single-pixel organic computational spectrometer (OCS) based on an organic photodetector (OPD) with a pseudoplanar heterojunction (PPHJ) active layer. Through controlled sequential deposition, a gradient donor-acceptor distribution is achieved, yielding bias-dependent spectral responses with strong nonlinear correlations (Pearson correlation coefficients from -0.07 to 1.00). The OCS achieves a high detectivity of 7.84 × 10¹² Jones and a fast response time of 2.85 μs, enabling accurate reconstruction of monochromatic and broadband spectra across 300-1000 nm range with a normalized root-mean-square error (NRMSE) as low as 0.0034. Moreover, the same device structure serves as a filterless quad-channel color sensor via photocurrent readout at four predefined bias voltages, bypassing the need for spectral filters or complex algorithms. This minimalist design, which delivers high performance from a single active layer, offers significant potential for portable and integrated spectroscopic applications.

The dense layer formed by the strong adsorption of ionomer on platinum (Pt) surfaces in cathode catalyst layers of proton exchange membrane fuel cells is a key factor limiting oxygen transport and can be significantly affected by the surface functional groups on carbon supports. This work employs molecular dynamics simulations to clarify how surface functional groups affect the oxygen transport resistance to the Pt surface and adopts density functional theory to reveal why the interaction between ionomer and Pt is altered by the surface functional groups. Aside from the enriching effects of water on Pt surfaces, we find that the adsorption of sulfonate ions (SO₃^-) is more preferred by the high-affinity functional groups on carbon surfaces, such as COOH, and thus significantly affects the interaction between SO₃^- and Pt surface, thereby reducing oxygen transport resistance. Moreover, the distance of functional group to Pt catalysts exhibits a nonmonotonic effect on the oxygen transport resistance: too close or too far from the Pt catalysts would weaken the effect of surface functional groups, while an optimal distance is around 7.38 Å, located outside the dense layer.

Abstract Deterministic closures for coarse-grained turbulence models help reproduce mean statistics, but often fail to capture the finite-time growth of uncertainty. Using the framework of shell models as a quantitative multi-scale testbed, we compare fully resolved simulations with large-eddy simulations using either stochastic or deterministic subgrid closures. While in the fully resolved system a single microscopic perturbation is rapidly amplified by strongly chaotic dynamics, truncation produces a strong delay and suppression of variance growth when uncertainty is introduced through initial condition perturbations only. We show that a data-driven Langevin-type stochastic closure restores the correct timing and magnitude of variance growth across scales, demonstrating that sustained stochasticity is essential for predictability in reduced turbulent dynamics.

Lithium-rich manganese-based layered oxides (LRMs) have emerged as attractive cathode candidates for next-generation lithium-ion batteries with high energy density. Their exceptional capacity originates from the synergistic contribution of cationic redox and oxygen anionic redox (OAR). However, the utilization of OAR reactions at high voltages (>4.45 V) inevitably triggers irreversible oxygen release, leading to surface phase transitions and bulk structural degradation, consequent rapid capacity fading, and voltage decay. Therefore, simultaneously stabilizing the bulk lattice and the interface is critical to achieving durable OAR reversibility and long-term stability. Herein, we propose a one-step H₃BO₃ treatment strategy to construct boron-modified Li_1.098Ni_0.138Co_0.138Mn_0.552B_δO₂ (B-LRM) with borate species (BO₃/BO₄) doping and an amorphous lithium borate surface layer. The incorporation of boron introduces strong B-O bonding, which modulates Mn-O covalency, enhances OAR reversibility, and mitigates lattice distortion, while the amorphous surface layer effectively stabilizes the cathode-electrolyte interface. Consequently, the B-LRM cathode exhibits a high specific capacity of 306 mAh g^-1 at 0.1 C. Moreover, it demonstrates remarkable long-term durability, maintaining 86.3% of its initial capacity after 400 cycles at 1 C, accompanied by a minimal voltage decay of only 0.9 mV per cycle. This work provides a facile and scalable approach for achieving LRM cathodes with high energy density and long cycle life.

We present a photothermal infrared spectroscopy-based approach for the chemical characterization and quantification of nanoplastics. By combining the high sensitivity of nanoelectromechanical systems (NEMS) with the wide spectral range and ubiquity of commercially available Fourier transform infrared (FTIR) spectrometers, NEMS-FTIR offers a time-efficient and cryogen-free option for the rapid, routine analysis of nanoplastics in aqueous samples. Polypropylene, polystyrene, and polyvinyl chloride nanoplastics with nominal diameters ranging from 54 to 262 nm were analyzed by NEMS-FTIR with limits of detection ranging from 101 to 353 pg, 1 order of magnitude lower than values reported for pyrolysis-gas chromatography-mass spectrometry of nanoplastics. The absorptance measured by NEMS-FTIR could be further converted to absolute sample mass using the attenuation coefficient, as demonstrated for polystyrene. Thanks to the wide spectral range of NEMS-FTIR, nanoplastic particles from different polymers could be readily identified, even when present in a mixture. The potential of NEMS-FTIR for the analysis of real samples was demonstrated by identifying the presence of nanoplastics released in water during tea brewing. Polyamide leachates in the form of fragments and smaller oligomers could be identified in the brewing water without sample preconcentration, even in the presence of an organic matrix. Accelerated aging of the nylon teabags under elevated temperature and UV radiation showed further release of polyamide over time.