Physics

The present work aims at an extension of the diffusion-reaction model to two spatial variables for treating positron trapping and annihilation at grain boundaries of polycrystals with grains of rectangular column shape. Analytical solutions for the positron lifetime spectrum and the mean positron lifetime are derived taking into account concomitant transition-limited positron trapping at intragranular point defects. Despite the two-dimensional nature of the diffusion-reaction problem, single-sum expressions could be deduced for the characteristic positron annihilation parameters. The relevant limiting cases are considered, i.e., entirely reaction-limitation, yielding the solution of standard rate theory, entirely diffusion-limitation as well as entirely reaction-limitation in one direction when the extension of the rectangular column in this direction is much shorter than in the other. The present model contains the known solution for the platelet structure as the limiting case of infinite extension of the rectangular cross-section in one direction. In the regime of reaction-controlled trapping, the positron trapping rate at grain boundaries is determined by the ratio between perimeter and cross-section of the columnar-shaped grains. Besides this geometric ratio, the shape of the columns (square-, rectangular-, cylindrical-shaped) becomes relevant, when positron trapping rate at grain boundaries is in addition diffusion-limited. .

Abstract The homochiral ligands (R)- and (S)-2-chloropropionic acid (R-HCPA and S-HCPA) were utilized to construct two pairs of new homochiral Dy2 complexes: [Dy2(R-CPA/S-CPA)2(L1)2(DMF)2]·2DMF (R-I/S-I) {H2L1 = [2-[(E)-(3-hydroxypyridin-2-yl)methylidene]diazanyl](3-aminopyrazin-2-yl)methanone} and [Dy2(R-CPA/S-CPA)2(L2)2(DMF)2] (R-II/S-II) {H2L2 = [2-[(E)-(2-hydroxyphenyl)methylidene]diazanyl](3-aminopyrazin-2-yl)methanone}. Dramatically, the atom modification of N→C(H) on the aromatic ring hydrazone Schiff base ligands caused a significant change in the coordination mode of (R)/(S)-2-chloropropionate (acting as bridging ligands in R-I/S-I and terminal ligands in R-II/S-II), which in turn led to a change in the space group: R-I and S-I are crystallized in the I41 space group but R-II and S-II display the P1 space group. These changes are related to the differences in the way hydrogen bonds form between molecules of these two pairs of enantiomers and whether lattice solvents are present. Magnetic measurements indicate that R-I and R-II are both ferromagnetically coupled and exhibit zero-field single-molecule magnet (SMM) behaviors, which can be explained theoretically. Notably, the magnetic relaxation of R-I consists of the Orbach process plus the weak Raman process, while the magnetic relaxation of R-II belongs to the Raman process plus the QTM, this is related to the fact that R-I is more rigid than R-II due to the rigidity enhanced by the chiral carboxylate-bridging ligands.

Abstract Flexible ion channels perform directional ion transport with high mechanical strength, which could bring many important intelligent applications. In this study, composite ink of graphene oxide (GO), tannic acid (TA), and cellulose nanofiber (CNF) is direct-write printed into a GO/TA/CNF porous structure (PS) with a freeze-dried process. With the negative charge of hydroxyl (-OH), carboxyl (-COOH), and phenolic hydroxyl (Ar-OH), the GO/TA/CNF PS of 3 cm length, 3 cm width, and 7 μm thickness realizes a maximum potential of 0.13 V and a maximum current density of 26.7 A/m2 in KCl solution with a 1000-fold salinity gradient. Meanwhile, an energy conversion efficiency of 36.98% and different cation transportation are realized. A hydrogen bond network of GO/TA/CNF PS is formed by intermolecular interaction among -OH and -COOH of GO, TA, and CNF, which could absorb external force and recover into the original structure through the elastic modulus of the hydrogen bond. With a stretching force of 152.7 MPa, a constant output current is exhibited with structural integrity. After 104 cycles bending at a 0.2 mm–1 curvature, output power density is only changed by 0.9%. Meanwhile, unchanged current is demonstrated after 35 h immersion in acidic or neutral solution, and changed current within 6% is obtained after 35 h immersion in alkaline solution. Furthermore, the flexible ion channel is used in wearable electronics as a wearable energy device or body fluid electrolyte monitor.

Abstract Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection, in which oxidative stress, ferroptosis, and macrophage-driven immune dysregulation form a self-amplifying pathological cycle. Epigallocatechin gallate (EGCG), a natural polyphenol with antioxidant and immunomodulatory activities, holds therapeutic potential for sepsis but is limited by rapid metabolism and low bioavailability. To overcome these limitations, we constructed ultrasmall Ce-EGCG nanoparticles (NPs) via one-pot metal-phenolic coordination self-assembly between cerium ions and EGCG. The resulting NPs exhibited excellent colloidal stability and efficient cellular internalization. Ce-EGCG NPs displayed dual catalase- and superoxide-dismutase-mimetic activities, scavenging both cytosolic and mitochondrial reactive oxygen species, and consistently outperformed equivalent doses of free EGCG and free Ce ions, demonstrating that the assembled metal-phenolic architecture is essential for the observed activity. In LPS- or H2O2-stimulated macrophages, Ce-EGCG NPs reversed Fe2+ overload, suppressed lipid peroxidation, and reprogrammed macrophages from a pro-inflammatory M1 toward an anti-inflammatory M2 phenotype. In CLP-induced septic mice, Ce-EGCG NPs ameliorated multi-organ injury, attenuated systemic cytokine storm, and improved survival, while showing favorable biosafety. Mechanistically, Ce-EGCG NPs activate the Nrf2/HO-1/NQO1 antioxidant axis and the GPX4/SLC7A11/ACSL4 anti-ferroptotic axis. Together, these findings show that Ce-EGCG NPs break the oxidative-ferroptotic-inflammatory cycle of sepsis through coordinated antioxidant, anti-ferroptotic, and immunomodulatory actions, offering a rationally designed nanotherapeutic strategy for sepsis and related inflammatory conditions.

Abstract Guanidinium iodide (GAI) and cesium iodide (CsI) have been demonstrated as effective functional additives to formamidinium iodide (FAI) and lead iodide (PbI2), respectively, significantly enhancing power conversion efficiency and stability of devices. Herein, GAI was incorporated into the PbI2 solution to establish hydrogen-bonding interactions with the Pb–I framework, enhancing the stability of the [PbI6]4– octahedral structure. However, the relatively large ionic size of the guanidinium cation (GA+) requires further lattice regulation to achieve structural balance. To address this, the current study introduces Cs+ ions, which have smaller atomic radii, to synergistically regulate crystal growth kinetics and successfully achieve lattice stress balance. Experimental results show that the synergistic effect of GAI and CsI significantly enlarges the perovskite grain size (from 433 ± 141 to 586 ± 243 nm) with fewer pinholes in the perovskite films, in favor of stability improvement. An n–i–p structured device based on this approach achieves an efficiency of 24.29% (compared to 22.66% for the control) and exhibits excellent storage stability under ambient conditions with 80 ± 5% relative humidity at room temperature—retaining 86% of its initial efficiency after 1000 hours of storage. This study provides a promising technological pathway for improving perovskite crystal quality and device performance through cation-size-engineering strategies.

Abstract The electronic structure of conventional two-dimensional transition metal dichalcogenides (TMDs) is highly sensitive to lattice deformation, often leading to indirect-to-direct band-gap transitions that compromise performance in flexible nanoelectronic applications. Janus TMDs, with their broken mirror symmetry and intrinsic out-of-plane dipoles, offer a promising alternative platform for electrostatic tuning. However, their electronic stability under strain and the role of the chalcogen-stacking sequence in their heterostructures remain poorly understood. Here, we study the strain tolerance and piezoelectric properties of MoSSe/WSSe heterobilayers from first principles. By examining different configurations, we demonstrate that the interface chemistry strongly modulates interlayer coupling, dynamic charge redistribution, and dipole interactions. Importantly, the combined effects of intrinsic electric fields and interface electrostatics effectively suppress the strain-induced band-gap transitions typical of conventional TMDs. Moreover, while the in-plane piezoelectric response remains nearly insensitive to the stacking order, the shear piezoelectric coefficient depends heavily on the interfacial symmetry and can be effectively tuned by strain modulation. Our results highlight interfacial engineering as a powerful route to design strain-resilient Janus heterostructures for next-generation flexible optoelectronic, valleytronic, and piezotronic devices.

Developing low-cost, highly efficient bifunctional non-noble-metal catalysts for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is crucial for the application of overall water splitting. Herein, we report the rational design of a CoS2/MoS2 heterostructure with abundant interfaces by a facile two-step hydrothermal strategy. Owing to its unique three-dimensional structure with rich channels, the CoS2/MoS2 assembly provides a large amount of electrochemically active surface area and charge transfer pathways. In addition, the electron transfer from CoS2 to MoS2 at the interfaces not only enhances the conductivity of MoS2 but also optimizes the adsorption of intermediates in both the HER and OER processes. More importantly, MoS2 and CoS2, serving as the active centers for HER and OER, respectively, work in synergy to jointly promote the splitting of water molecules. Consequently, the optimized CoS2/MoS2-0.1 (where "0.1" represents the Co/Mo molar ratio) electrocatalyst exhibits excellent bifunctional performance with small overpotentials of 127 mV for HER and 252 mV for OER at 10 mA cm-2, as well as good stability for 24 h. In addition, a low cell voltage of 1.61 V is required to achieve the current density of 10 mA cm-2 toward overall water splitting by assembling CoS2/MoS2-0.1 into a two-electrode electrolyzer.

Maintaining a dynamic humidity-thermal balance within the skin-device microclimate is critical for enhancing wearability and minimizing physiological and psychological discomfort. Herein, we present an asymmetric dual-responsive MXene/Viscose-PP (MVP) actuator integrated into a Janus photothermal mask for skin-mask microclimate dynamic humidity-thermal regulation. The MVP actuator switch with asymmetric bending deformation can achieve autonomous on-off switching under temperature and humidity stimulation. The Janus photothermal mask enables unidirectional transport of exhaled breath condensate to the outer hydrophilic layer and enhances evaporation efficiency by 22.5 times. The synergistic integration of the Janus photothermal interface and the MVP actuator switch establishes a closed-loop dynamic humidity-thermal regulation system. The smart switch-based Janus photothermal mask achieves a state of humidity-thermal comfort during prolonged wearing. Such a closed-loop strategy offers a transformative route toward next-generation adaptive personal protective equipment and smart textiles, enabling autonomous human-machine humidity-thermal interaction without external energy consumption.

Non-enzymatic glucose sensors have the advantages of low cost, high sensitivity, stability, and good shelf life. The porous laser-induced graphene (LIG) on flexible substrates obtained by a simple fabrication process shows good conductivity and porous morphology advantageous for sensing. Herein, flexible and non-enzymatic glucose biosensors are fabricated based on a composite of copper nanoparticles (CuNPs) anchored on LIG. The fabrication process involved a non-contact, simple, and cost-effective electrospray reduction (ESR) deposition technology, where an aqueous copper ion solution serves as the ESR precursor. The positively charged micro-scaled droplets generated by electrospray act as micro-reactors, in which the potential difference between the charged droplets and the negatively biased substrate drives the in situ reduction of Cu2+ to CuNPs. This non-contact ESR process enables the conformal deposition of CuNP catalysts on LIG, utilized here for glucose sensing. The size and distributions of the CuNPs can be tuned by the ESR parameters. The optimized sensors demonstrate excellent performance for glucose detection in KOH alkaline electrolyte, exhibiting a sensitivity of 622.9 μA·mM-1·cm-2, a limit of detection of 29.73 μM, and a wide linear range from 0.05 to 10 mM, as well as remarkable repeatability and selectivity for glucose. The ability for detection of glucose in neutral PBS buffer (pH 7.4) was also demonstrated. The ESR process provides a rapid and green fabrication of reliable non-enzymatic glucose sensors and presents a promising processing strategy for wearable and flexible health monitoring devices.

Abstract We investigate the evolution of information content in black holes using a quantum probabilistic entropy within canonical quantum gravity. Employing the Wheeler-DeWitt framework with a Kantowski-Sachs metric for the black hole interior and a minimally coupled Klein-Gordon field, we derive and solve the Wheeler-DeWitt equation in the minisuperspace. The resulting wave function yields a quantum probabilistic entropy that quantifies the information content of the black hole. A challenge in studying its evolution is the absence of an explicit time parameter, reflecting the problem of time in quantum gravity. To address this, we use the Schwarzschild radius as an effective clock, utilizing its monotonic decrease during Hawking evaporation. The resulting entropy evolution exhibits a curve remarkably similar to the Page curve. Although quantum probabilistic entropy is distinct from von Neumann entropy, this behavior suggests that effective notions of time and information evolution can emerge naturally from non-perturbative quantum gravitational dynamics.

Abstract Precise and on-demand regulation of cellular secretion is essential for effective and safe therapeutic intervention; however, most open-loop secretion strategies have limited integration of physiological feedback and require the introduction of synthetic genetic circuits, thereby constraining adaptive secretion control and increasing system complexity. Here, we present a transgene-free photothermal strategy for enhancing insulin secretion that integrates externally programmable open-loop control with physiology-coupled feedback regulation by directly leveraging endogenous voltage-gated Ca2+ channels (VGCCs), Ca2+-dependent exocytotic machinery, and the glucose-stimulated insulin secretion (GSIS) feedback loop. Mesoporous polydopamine nanoparticles functionalized with a near-infrared absorber (mPDA-IR) are coupled with MIN6 pancreatic β cells, which are subcutaneously implanted into type 1 diabetic mice. Under hyperglycemic conditions, mild photothermal activation (<42 °C) enhances membrane depolarization and VGCC activation, thereby amplifying Ca2+ oscillations and driving Ca2+-dependent insulin secretion. In vitro, photothermal modulation reproducibly evokes Ca2+ responses and propagates intercellular Ca2+ waves in both two-dimensional cultures and three-dimensional pseudoislets. Notably, insulin secretion is minimal under glucose-free conditions but robust under hyperglycemia. In vivo, a single photothermal stimulation adaptively enhances insulin secretion and efficiently restores blood glucose levels from severe hyperglycemia (≈550 mg/dL) to normoglycemia in type 1 diabetic mice. Collectively, this work establishes a transgene-free, externally actuated yet physiologically self-regulated strategy for precise regulation of cellular secretion.

Abstract The antioxidant treatment for atherosclerosis has presented a paradox: theoretically feasible but clinically ineffective. In this study, we developed an “oxidative stress clock” nanoprobe to dynamically monitor oxidative stress at different stages of atherosclerosis, thereby dissecting the optimal time window for antioxidant intervention. This probe could simultaneously and specifically recognize hydrogen peroxide, protein sulfenylation, and protein phosphorylation in vitro and in vivo, enabling accurate mapping of the evolution of oxidative stress during disease progression. Using this probe, we discovered that the effective window for antioxidant intervention is limited to the stage of reversible protein oxidative modification. However, clinical ultrasound imaging identifies plaques well after this critical window, which directly contributes to the clinical failure of antioxidant therapy. Furthermore, the underlying molecular mechanism driving oxidative stress-mediated atherosclerosis progression (ox-LDL→H2O2→EGFR/Src/PTP1B-SOH→p-MAPK→atherosclerosis) was uncovered.

Abstract Ion transport in nanostructured materials is critical to numerous applications. In most solid-state ion conductors, polymers, and conventional ionic liquids, ion mobility is closely linked to the strength of ion coordination site interaction energies, which are dictated by ion size and valence. Here, we investigate how the size and valence of cation solutes impact phase behavior, solvation environment, and ion mobility in adamantane-derived solid organic electrolytes. We find that the ionic liquid 1-(adamant-1-yl)-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([AdImMe][TFSI]) templates size-selective ion-transport domains that preferentially pass lithium and magnesium over larger alkali and alkaline-earth cations. Our structural and spectroscopic analyses reveal that the incorporation of larger ions induces structural reconstruction within the TFSI domains, disrupting the ion-transport channels and hindering ion mobility, while the local chemical environment around adamantane groups remains unchanged. We further observe that lithium- and magnesium-containing mixtures exhibit surprisingly similar phase behavior and conductivity, particularly when compared to mixtures composed of sodium and potassium solutes. These magnesium-containing mixtures exhibit conductivity on the order of 0.1 mS cm–1 at 75 °C, which is competitive with other solid-state magnesium ion electrolytes under evaluation for use in multivalent batteries. Our discovery that adamantane-templated electrolytes are nonconductive to sodium and potassium ions while exhibiting significant lithium conductivity suggests the potential for these materials to serve as electrochemical membranes for direct lithium extraction from brines. Overall, our results indicate that diamondoid self-assembly can be utilized to template size-selective ion mobility in electrolytes to address emerging challenges in energy storage and resource recovery.

Abstract Bioorthogonal chemistry provides a compelling strategy for in situ cytotoxin generation. However, the clinical translation of conventional bioorthogonal catalysts is impeded by poor tumor accumulation, insufficient targeting specificity, limited in vivo catalytic efficiency, and inadequate spatiotemporal control. Meanwhile, excessive lactate accumulation in the tumor microenvironment (TME) drives metabolic reprogramming, malignant progression, and therapeutic resistance. Here, we develop a living bacterial hybrid reactor by integratingShewanella oneidensis MR-1 (S.o) with Cu(II)-based zeolitic imidazolate frameworks to enable metabolism-guided and tumor-confined bioorthogonal catalysis. Exploiting the intrinsic hypoxia tropism of S.o, the hybrid reactor selectively accumulates within the TME. In the lactate-rich tumor, endogenous lactate drives bacterial reduction of inert Cu(II) to active Cu(I), enabling in situ catalyst activation and concurrent lactate depletion. The generated Cu(I) catalyzes a localized azide–alkyne cycloaddition between systemically administered prodrugs, producing a combretastatin A-4-like cytotoxin. Simultaneously, intracellular Cu(I) overload induces cuproptosis, while lactate depletion disrupts tumor metabolic homeostasis, together eliciting a synergistic triple antitumor effect. This work establishes a generalizable paradigm in which living bacterial vectors function as both tumor-targeting carriers and self-sustaining biochemical reactors, overcoming key limitations of conventional bioorthogonal catalysis and enabling precise, tumor-confined therapeutic activation.

Abstract Shortwave infrared (SWIR) photodetectors are crucial for emerging technologies such as autonomous driving, smart agriculture, industrial inspection, and eye-safe LiDAR. Colloidal indium arsenide (InAs) quantum dots (QDs) offer a low-cost, RoHS-compliant alternative to epitaxial III–V semiconductors. But their performance is limited by a high density of surface trap states that induce nonradiative recombination and potentially give rise to a high dark current in photodiodes. Here, we demonstrate that InF3 can effectively passivate these surface traps, significantly improving both optical and electronic properties. In nonpolar solvents, a simple InF3 treatment on oleylamine/chloride-capped In(As,P) and oleate-capped InAs QDs increases the photoluminescence quantum yield to 13% and 4%, respectively─the highest reported for core-only InAs QDs. In polar media, the InF3 treatment remains effective but reduces colloidal stability. To overcome this limitation, a solid-state in situ InF3 treatment of QD films was used. The treatment doubles the carrier lifetime and lowers the dark carrier density, confirmed by ultrafast transient absorption spectroscopy, microwave conductivity, and electrochemically gated transistor measurements. In SWIR photodetectors, this leads to an order-of-magnitude reduction in dark current density and a 3-fold increase in the calculated specific detectivity, assuming it is shot-noise-limited. Temperature-dependent dark current density and thermal admittance spectroscopy measurements reveal that deep trap states dominate the dark current in InAs QDs photodetectors. The InF3 treatment strongly suppresses these traps. These findings establish InF3 passivation as a powerful, promising strategy for mitigating surface-trap-induced dark current and advancing high-performance, RoHS-compliant SWIR photodetectors.

Abstract Spin-selective carrier transport in low-dimensional magnetic semiconductors is central to the development of next-generation spintronics. However, achieving robust spin-filtering together with long spin-coherence under nonequilibrium conditions remains a major challenge. Recently isolated by top-down exfoliation, the CrSbSe3 nanowire has emerged as a ferromagnetic semiconductor exhibiting enhanced coercivity compared to its bulk counterpart. Here, using first-principles density functional theory combined with quantum transport calculations, we demonstrate that the CrSbSe3 nanowire is a ferromagnetic semiconductor with a band gap of 1.26 eV. We identify superexchange interactions mediated by Se(p-orbitals) as the primary mechanism stabilizing its ferromagnetic order. Noncollinear spin calculations including spin–orbit coupling reveal an unchanged band topology near the Fermi level, suggesting long spin-coherence. Quantum transport calculations reveal robust spin-selective conduction, with the spin-injection factor approaching 100% for biases up to 0.6 V, independent of channel length, establishing the CrSbSe3 nanowire as a promising spin-filtering platform for spintronics.

Abstract We demonstrate that the accepted model for transport in semimetals gives incorrect results and introduce a corrected scheme that reproduces experimental data. Carrier densities in semimetals have been systematically overestimated by factors of 2–5 throughout the literature, leading to underestimated mobilities by the same factor. This resolves the long-standing puzzle of why nominally identical graphene samples show order-of-magnitude mobility variations. By integrating the density of states from the Fermi level rather than from band edges, we reproduce the full evolution of the Hall coefficient and longitudinal resistance across five independent graphene data sets with zero fitting parameters. A double-normalized polar representation reveals a decisive signature: a smooth arc that experimental data match, while no realistic density of states or mobility rescues the band-edge model. Our Fermi model provides a parameter-free, temperature-robust description with immediate implications for reevaluating mobility benchmarks across the 2D materials literature.

Abstract Cardiovascular disease, driven primarily by atherosclerosis, remains a leading cause of global mortality. Lipid-lowering therapies reduce risk by less than one-third, leaving substantial residual inflammation compounded by rapid drug clearance and limited plaque targeting. Biomimetic systems such as cell-membrane coating enhance lesion targeting but lack intrinsic activity and are prone to biological barriers. Herein, we engineered living fused cell (FC) microrobots combining mesenchymal stem cells and M2 macrophages, capable of inheriting the therapeutic ability of both and modulating pathophysiological responses. Gold nanowaxberries (AuMWs) conjugated to antisense miRNA33 were loaded into the FCs. In vivo AuMW-anti-miR33@FCs modulated inflammation and immune microenvironment, augmented cholesterol efflux, and reduced plaque burden by 64.9% versus controls. Treatment was tracked by photoacoustic imaging via AuMWs. Overall, this synergistic strategy offers a promising platform for atherosclerosis cardiovascular disease diagnosis and therapy.

Abstract Due to the significant friction and wear in micro- and nano-electromechanical systems (M/NEMS), achieving reliable sliding in M/NEMS remains a critical challenge. Structural superlubricity with ultralow friction and wear in van der Waals (vdW) heterojunctions is a promising route to realize long-lifetime sliding in M/NEMS for practical applications. However, the fundamental origin of friction in vdW heterojunctions remains elusive. In this paper, through detailed experimental measurements by adopting various slider geometries and cracked substrates, we demonstrate that friction is dominated by edge and corner effects, driven by the pinning effects associated with moiré superlattices at these boundaries. Specifically, friction enhancement correlates inversely with the radius of curvature at the corners. Furthermore, edges oriented perpendicular to the sliding direction induce more pronounced frictional enhancement than those aligned parallel. These results elucidate a fundamental frictional mechanism in vdW heterojunctions, providing critical insights for the design of future M/NEMS.

Abstract Significant efforts have recently been dedicated to enhancing reversibility and safety of high-temperature lithium–chalcogenide batteries (LCBs) to address performance-limiting issues. However, bottlenecks in electrolyte design that severely constrain the utilization of active material and reversibility of a lithium anode at elevated temperatures have received little attention. Herein, we report a nonflammable sulfonamide deep eutectic electrolyte (SDEE) composed of N,N-dimethylmethanesulfonamide and lithium bis(trifluoromethanesulfonyl)imide for high-temperature LCBs. The SDEE exhibits good thermal stability, high lithium-ion transference number, and a wide electrochemical window. Additionally, SDEE facilitates the formation of a compact and uniform lithium deposition, leading to a much mitigated shuttle effect and improved reversibility of the lithium anode compared to an ether-based electrolyte. LCBs with an SDEE exhibit a low overcharging degree at 60 °C (8.4%) and a high specific capacity (∼1107 mAh g–1) at 328.2 mA g–1. This work offers a viable electrolyte design concept for safe batteries targeting elevated temperatures using high-capacity electrodes.

Abstract Rechargeable aqueous Zn–I2 batteries are attractive for safe, low-cost energy storage but remain fundamentally limited by severe self-discharge and poor cycling stability because sluggish ZnI2 oxidation impedes efficient iodine regeneration during charging. Herein, we confine highly dispersed iodine quantum dots within a Fe(CN)64–-doped polypyrrole/polyaniline framework to establish a free-energy-gradient-driven regeneration pathway. During discharge, Fe-cyanide and N-rich sites immobilize polyiodide intermediates, suppressing shuttle and self-discharge. More importantly, during charging, the in situ generated ZnxFeIII(CN)6/Znx+1FeII(CN)6 redox couple establishes an intrinsic free-energy gradient that couples Zn2+ transfer with iodide oxidation, thereby directing iodine regeneration and limiting aggregation. The resulting cathode delivers 238.2 mAh g–1 at 0.5 A g–1, maintains approximately 217 mAh g–1 at 10 A g–1, retains 92.6% capacity after 50,000 cycles with nearly 100% Coulombic efficiency, and supports stable pouch-cell and flexible microbattery operation. These results establish free-energy-gradient engineering as a strategy for regulating reversible halogen conversion beyond static confinement.

Abstract The relentless demand for energy-efficient electronics creates a critical thermal bottleneck. A long-standing paradigm holds that compressive strain universally degrades thermal transport in two-dimensional (2D) materials by inducing phonon-scattering wrinkles. Here, we overturn this in MoS2 by demonstrating that substrate-confined, wrinkle-free compression drastically enhances its in-plane thermal conductivity. This feature is achieved through a substrate confinement strategy that enables uniform, wrinkle-free compression. We experimentally measured a remarkable 40% boost in thermal conductivity with merely 1% compressive strain, an effect that starkly contrasts with the suppression observed under tension. Molecular dynamics simulations reveal that the substrate suppresses out-of-plane instabilities via van der Waals coupling, facilitating an unprecedented strain transfer. First-principles calculations further reveal that the compressive strain reconfigures the crystal symmetry, concurrently increasing phonon group velocities and prolonging phonon lifetimes. This work resolves a critical bottleneck in 2D thermal management and unlocks a new pathway for the atomic-scale design of high-thermal conductivity materials for next-generation electronics.

Abstract Electrochemical urea synthesis from CO2 and nitrite (NO2–) offers a sustainable route for carbon and nitrogen cycling, yet it is hindered by the kinetic imbalance between the sluggish CO2 reduction reaction (CO2RR) and the more facile nitrite reduction reaction (NO2RR). Inspired by the rhizobial cell wall, a natural multifunctional interface that coordinates gas, ion, and molecular transport, we designed a cell-wall-mimetic electrocatalyst featuring a Cu2O/Cu core encapsulated within a pyrrolic-N-containing graphitized porous carbon shell (Cu2O/Cu@C). This bioinspired architecture functions as a nanoregulator to structure a high-density triple-phase interface (gas–liquid–solid interface), manage wettability for concurrent CO2 and electrolyte access, enrich key reactive intermediates, and stabilize the active core. The catalyst achieves a urea yield rate of 50.2 mmol/g/h with a Faradaic efficiency (FE) of 60.6% at −0.6 V, demonstrating that mimicking biological interface principles can effectively harmonize kinetic mismatches in complex cooperative electrocatalysis.