Browse Articles

Unveiling the Dilution‐Shielding Effect as a Universal Strategy for Interfacial Regulation in Composite Polymer Electrolytes

ABSTRACT Composite solid electrolytes integrating poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVDF‐HFP) with garnet‐type ceramic fillers offer a balance of mechanical flexibility and ionic conductivity, yet parasitic interfacial reactions compromise long‐term chemical and electrochemical stabilities. PVDF‐HFP undergoes dehydrofluorination when lanthanum (La) sites on garnet fillers coordinate with polar solvents, creating alkaline microenvironments that accelerate polymer degradation. Here, we unravel a dilution‐shielding effect that offers a universal strategy for promoting interfacial passivation of composite polymer electrolytes (CPEs) and enabling uniform Li + transport. Specifically, incorporating fluoroethylene carbonate (FEC) with an ultrahigh dielectric constant effectively attenuates the activity of strongly basic coordinating solvents and electrostatically shields La sites, thereby effectively preventing the formation of alkaline microenvironments and alleviating dehydrofluorination. This simple strategy also concurrently drives in situ formation of a LiF‐rich protective interphase. Comprehensive in situ characterizations substantiate that the resulting FEC‐modified CPE enables enhanced interfacial passivation and stable Li + transport. Consequently, Li|Li symmetric cells achieve stable cycling for over 700 h at 0.1 mA cm −2 , and LiFePO 4 |Li full cells deliver more than 1200 cycles at 1C with 90.2% capacity retention. This work establishes the dilution‐shielding effect as a transferable interfacial regulation strategy, providing new insights into the design of chemically and electrochemically stable solid‐state lithium metal batteries (ssLMBs).

Surface/interface regulation of NiMo-based catalysts for durable anion exchange membrane water electrolysis under intermittent operation conditions

Encouraging progress has been made in boosting the hydrogen evolution reaction (HER) activity of NiMo-based catalysts. However, their practical application in anion exchange membrane water electrolysis (AEMWE) systems still faces the obstacle of stability, especially under intermittent operation conditions. Here, we developed an innovative electrodeposition method to regulate the surface/interface of NiMo-based catalysts by simultaneously adding a P source and an ammonium additive to the deposition precursor solution. The best-performing NiMoP-A catalyst exhibits excellent HER performance with an overpotential of only 175 mV at a current output of 1000 mA/cm2, which can be attributed to the improved specific surface active sites, enhanced hydrogen binding energy, and optimized OH binding energy. Furthermore, when paired with a bare Ni foam anode in AEMWE, the device with NiMoP-A cathode exhibits ultra-high stability with almost no decay during the accelerated stress testing involving 10k startup/shutdown cycles. Such stability originates from the synergistic effect of P-doping and ammonium additives, which jointly modulate the surface/interface of the catalyst, thereby enhancing both mechanical and chemical stability. This study provides key insights into enhancing electrode stability in AEMWE under intermittent operation conditions.

Self‐assembled Helical Tetramer Stack of Terrylene Bisimide in Solution and Crystalline State

ABSTRACT A terrylene bisimide (TBI) derivative 1 bearing bulky meta ‐terphenyl imide substituents is shown to self‐assemble into helical [1 4 ] tetramer stacks in solution. Driven by strong dispersion and electrostatic forces, a direct transition from monomers into defined tetramers is already observed in the micromolar concentration range (∼10 −6  M) in methylcyclohexane at room temperature, corresponding to a π–π‐interaction strength of Δ G  = −40.1 kJ mol −1 for the respective π–π‐stacking interaction between two neighboring TBIs. Upon addition of perylene ( P ), a further growth of the stacks toward [P . 1 4 . P] hexalayers is observed where the guest molecules are stacked at the peripheral positions. In contrast, upon addition of the larger coronene ( C ), the equilibrium shifts toward 1:2 complexes [C . 1 . C] where each TBI is surrounded by two coronene neighbors. Single crystal X‐ray analyses of the pristine [1 4 ] tetramer stack as well as the [P . 1 4 . P] hexalayer stack and the 1:2 trilayer [C . 1 . C] unambiguously confirm the unique stacking arrangements.

Interplay of Kondo physics with incommensurate charge density waves in CeTe3

CeTe3 is a 2-dimensional (2D) Van der Waals (VdW) material with incommensurate charge density waves (CDW), extremely high transition temperature (TCDW), and a large momentum-dependent CDW gap that leaves a significant portion of the Fermi surface intact. It is also considered to be a weak Kondo system, a property unexpected for a material with incommensurate CDW, where each atomic site is slightly different. Here, we study the properties of the CDW state in several RTe3 (R is rare earth) materials and examine the hybridization of itinerant states with the localized Ce 4f multiplet in CeTe3 by using angle resolved photoemission spectroscopy. We find that the renormalization of the itinerant states originating from the hybridization with the deeper localized 4f states at −260 meV is k−dependent and extends to the Fermi level. As these localized states are far from the Fermi level, the observed hybridization affects the effective masses only marginally and does not lead to heavy fermions. However, since the same renormalizing mechanism normally leads to the heavy fermion physics when the localized 4f states are near the Fermi level, our observation of its strong k−dependence suggests that this could be the reason for discrepancy between the heavy masses in specific heat and light ones in Shubnikov de Haas oscillations, often observed in heavy fermions.

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Self-compensation of temperature drift for MEMS resonant pressure sensors based on dynamic Joule heating modulation

This paper proposes and experimentally validates an active temperature drift compensation method for electrostatic actuation-piezoresistive detection microelectromechanical systems (MEMS) resonant pressure sensors. The method dynamically adjusts the voltage across the sensing piezoresistors to actively regulate the local temperature and thermal stress distribution of the resonant beam using the generated Joule heating effect, thereby offsetting the frequency drift caused by changes in ambient temperature. Experimental results show that the dynamic compensation scheme can significantly reduce the frequency drift of the sensor from 168 to 8.5 Hz within the wide temperature range of −45–85 °C, and the maximum fitting error within the full temperature range and full pressure range (10 kPa–5 MPa) is only 0.0058% FS. In addition, the scheme improves the quality factor (Q-factor) and short-term frequency stability of the sensor at high temperatures. This work provides a low-complexity and high-efficiency dynamic self-compensation solution for achieving high-precision and high-stability MEMS resonant sensors.

Unveiling the Electrochemical Reactivity of Urethane Toward Different Bond Formations and Application to Polyurethane Deconstruction via C─N Bond Formation

ABSTRACT Plastics are essential, and their production is increasing. The rate of plastic recycling is extremely low, and end‐of‐life plastics are sent to landfills and oceans, which is alarming. Mechanical recycling is not a viable solution because it produces downgraded materials. Efficient methods for chemical recycling of plastics are essential. Polyurethane is a widely used plastic, and the presence of very stable carbamate functionality makes its recycling extremely difficult. Existing methods require expensive reagents and harsh reaction conditions, such as high temperature, high pressure, and precious metal catalysts such as iridium and ruthenium. Electrochemistry can potentially be used to develop sustainable methods that can operate under milder conditions using fewer reagents. We disclose that urethane serves as an efficient carbamoylation reagent under electrochemical conditions at lower temperatures to form C─N, C─P, and C─C bonds. This method works successfully to deconstruct commercially available polyurethane using different amines. Furthermore, the robustness of the method has been tested on daily life plastics made of polyurethane with additives, such as flexible tubing and mobile covers. This method has also been applied for polymer backbone editing by converting the urethane linkage to urea upon reaction with diamine.

Spontaneously evolving intermittent shear fractures reproduce the fault formation and isolated earthquake sequence

When a system is subjected to continuous loading beyond its critical threshold, intermittent energy release events occur. Such behavior is observed in systems that span a wide range of temporal and spatial scales. Here, we propose a unique offset-compression loading system based on AZ31 magnesium alloy capable of spontaneously evolving intermittent shear fracture events. The intermittent fractures spontaneously evolve into a self-organized critical state characterized by avalanche-like shear fracture events. In addition, this system enables the coupling of fault formation and seismic events within the framework of an intermittent shear fracture process with spontaneous shear band nucleation. During individual shear fracture events in the magnesium alloy, this system is found to replicate the formation initiation and slip characteristics of both reverse and strike-slip fault systems. By measuring the energy release, we further show that the concentrated energy release during intermittent shear fracture is consistent with the seismic energy release pattern of the isolated earthquake sequence.

Photoinduced Generation of (Boryl)Silyl and (Chloro)Silyl Radicals: Access to Trisubstituted Silylboranes and Chlorosilanes

ABSTRACT Trisubstituted silylboranes and chlorosilanes are in high demand for the precise synthesis of tetrasubstituted organosilicons. However, conventional synthetic methods often require harsh conditions and exhibit low functional‐group tolerance, limiting their chemical diversity. In this study, we present a versatile photoinduced hydro(boryl)silylation and hydro(chloro)silylation of alkenes to construct trisubstituted silylboranes and chlorosilanes. This method employs the in situ generation of novel silyl radicals, such as (boryl)silyl radicals (R 2 (pinB)Si•) or (chloro)silyl radicals (R 2 ClSi•), from hydroborylsilanes or hydrochlorosilanes through highly selective hydrogen‐atom transfer. The unprecedented silylboranes and chlorosilanes obtained using this method enable the direct synthesis of highly complex tetrasubstituted organosilicons. Mechanistic studies reveal a photoactivation pathway in which a sulfur radical generated from a combination of ( t BuO) 2 and i Pr 3 SiSH directly facilitates Si─H bond cleavage without inducing any redox events at the Si─B/Si─Cl bonds, enabling radical hydrosilylation with a broad scope of alkenes.

Beyond a single mechanism: Uncovering the dual origin of degradation in <b> <i>β</i> </b> -Ga2O3 SBDs under forward bias stress

This study delineated the degradation of β-Ga2O3 Schottky barrier diodes under forward bias stress and identified the physical cause of performance instability in these diodes. Stress was found to increase the reverse leakage current and the forward current under low biases and decrease the turn-on voltage. The values of these parameters were partially recovered after annealing. The increased noise power spectral density after stress application was completely recovered after annealing, indicating that device degradation caused by interface defects is reversible. From the temperature-dependent low-frequency noise results, the interface defect energy levels were determined to be about EC −0.35 eV (EC = conduction band minimum). Deep-level transient spectroscopy technology traced the remaining irreversible degradation to E2* bulk defects. This dual-mechanism framework provides a clear physical explanation of degradation and offers crucial insights for enhancing the long-term stability of Ga2O3 power devices.

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Evolution of the below-bandgap anisotropic refractive indices and dielectric functions of β-(Al <i>x</i> Ga1 <b>−</b> <i>x</i> )2O3 (0 <b>&amp;lt;</b> x <b>&amp;lt;</b> 0.25) determined by generalized spectroscopic ellipsometry

We determine the composition dependence of the below-bandgap anisotropic refractive indices and dielectric functions of β-(AlxGa1−x)2O3 for x up to 25% Al. We use Mueller matrix generalized spectroscopic ellipsometry and investigate a set of high quality single crystalline bulk (x=0%,5%,10%,15%,20%,25%) and thin film (4.6%, 9.7%, 12%, 15%, 16.3%, 21%) samples grown by the Czochralski method and by plasma-assisted molecular beam epitaxy, respectively. Bulk samples with 0.2% silicon doping are cut from ingots with (100) surface and the unintentionally doped thin films samples are grown pseudomorphically on (010) β-Ga2O3. The combination of ellipsometry data from both sample sets permits to fully determine the optical properties of the transparent alloys. We employ a quasi-orthorhombic approach which ignores the very small shear components induced by the monoclinic crystal structure. We also ignore the possibly small effects due to strain within the pseudomorphically grown epitaxial samples. We report indices and dielectric functions for polarization along lattice vectors a, b, and reciprocal lattice vector c⋆. All indices reduce with increasing incorporation of aluminum while the spectral range of transparency increases due to the increase in bandgap energy with composition. We use our results to predict Bragg reflector multilayer structures on b-plane β-(Al0.20Ga0.80)2O3, for use in polarization sensitive narrow-band optical filters in the short wavelength region.

Sequence‐Modulated Active Tripeptide Condensates for Tandem Catalysis

ABSTRACT Biomolecular condensates formed via liquid‐liquid phase separation function as dynamic organelles that are vital to regulating cellular activities. Peptide‐based coacervates have emerged as appealing candidates to resemble key properties of biomolecular condensates. However, their application as adaptive organelles has been hindered by structural complexity and limited control over phase‐separation. Here, we present short tripeptide coacervates with tunable phase‐separation behaviors governed by composition and peptide sequence, significantly reducing molecular complexity. These tripeptide condensates exhibit enzyme‐regulated phase‐separation, closely mimicking the dynamic nature of biomolecular condensates. A key attractive feature of the tripeptide coacervates is their capability to sequester both hydrophobic active species and hydrophilic enzymes. This unique property enables the execution of confined tandem reactions in aqueous conditions. When incorporated into membrane‐bound artificial cells, this tripeptide coacervates serve as adaptive sub‐organelles, orchestrating compartmentalized catalytic cascades. This work highlights the potential of minimalistic peptide systems as functional microreactors with biomimetic and catalytic capabilities.

Acceptor doping enhanced defect effects on the electrical properties of PZST antiferroelectric ceramics

Chemical doping is a key approach to tailoring the properties of PbZrO3-based antiferroelectric materials. However, defects introduced during aliovalent doping can sometimes play a decisive role in regulating material properties. Here, we systematically investigate the effects of doping with Gd3+, Ba2+, and K+ ions on the phase structure and physical properties of Pb[(Zr0.7Sn0.3)0.94Ti0.06]O3 (PZST94/6). Gd3+ doping enhances antiferroelectricity, while Ba2+ doping enhances ferroelectricity, consistent with predictions based on tolerance factor and electronegativity. In contrast, doping with large-radius K+ ions contradicts the above predictions and unexpectedly stabilizes the antiferroelectric phase. The mechanism involves a significant increase in oxygen vacancy concentration upon K+ doping, which leads to the formation of defect dipoles. The local internal electric field generated by these dipoles interferes with polarization switching, ultimately raising the phase transition electric field while lowering both remanent and maximum polarizations in PZST94/6 ceramics. This work demonstrates that defect engineering can override conventional predictions based on ionic radius and electronegativity parameters, thereby offering a novel strategy for designing high-performance antiferroelectric materials.

Chiral Transcription on Achiral Carbon Dots by Linking with Chiral Histidine for pH‐Tunable Dual‐Mode Chiroptical Switch in Circular Dichroism and Circularly Polarized Luminescence

ABSTRACT Carbon dots (CDs) have garnered significant attention for developing stimuli‐responsive chiroptical nanomaterials. However, CDs featuring simultaneously reversible electronic circular dichroism (ECD) and intrinsic circularly polarized luminescence (CPL) have not yet been reported. Herein, we developed a novel kind of dual‐mode chiroptical switches based on achiral CDs through post‐modification with L‐/D‐histidine (L‐/D‐His). Through a mild amidation reaction, L‐/D‐His is not only covalently linked to the surface of CDs, but also closely attached to the luminescent centers via non‐covalent hydrogen‐bonding and π–π interactions, which facilitate efficient chiral transfer from L‐/D‐His to the luminescent centers of the CDs. Consequently, the chiral His‐modified achiral CDs (L‐/D‐His‐CDs) exhibit attractive chiroptical properties with both elegant ECD and intrinsic CPL across the entire visible spectrum. Intriguingly, the ECD and CPL signals of L‐/D‐His‐CDs can be reversibly switched to those of their enantiomers by alternating pH values between neutral and basic conditions. Our results indicate that the pH‐modulated protonation and deprotonation of imidazole directly modulate the surface non‐covalent interactions, triggering chiral conformational inversion and thereby enabling reversible ECD and CPL signals. This study establishes a facile strategy for the construction of stimuli‐responsive chiroptical switches from achiral CDs by rational chiral ligand modifications.

Epitaxial <b> <i>γ</i> </b> -CoMn films for antiferromagnetic spintronics

γ -phase alloy materials are of great interest for spintronics due to their antiferromagnetism depending on the interatomic separation. γ-CoMn, as a typical antiferromagnetic 3d transition metal alloy, has been the subject of numerous studies regarding its underlying antiferromagnetism origin determined by the competition between interatomic exchange interactions and interatomic election motion. However, the difficulty of growing single-crystalline γ-CoMn films on insulating substrates has prevented from their magnetoelectronic transport investigations and further applications. Here, we report the epitaxial growth, structural characterization, and magnetic and transport properties of γ-Co40Mn60 films on Cu buffered Si(111) substrate. Reflection high-energy electron diffraction and high-resolution x-ray diffractometry have manifested the successful epitaxial growth of high-quality γ-Co40Mn60 films. The antiferromagnetism resistivity minimum with temperature and Hall resistance deviation from magnetization indicate γ-CoMn is a promising antiferromagnetic material for spintronic investigations.

Hydrogen Aggregation Enhances CO ₂ Hydrogenation to Methanol Over In ₂ O ₃ ‐Based Catalysts

ABSTRACT The hydrogen (H) spillover on the catalyst surface is crucial in the CO 2 hydrogenation reaction, but its effects on product selectivity have been rarely investigated. Herein, we reveal the H‐spillover mediated regulatory role of oxide supports, which changed the CO 2 hydrogenation selectivity on In 2 O 3 ‐based catalysts. By replacing the supports from TiO 2 to ZrO 2 , the primary product of CO 2 hydrogenation experiences a significant shift from carbon monoxide (95.6%) to methanol (84.2%). In situ characterization and theoretical modeling evidence that the degree of H‐spillover influences the distribution of surface hydrogen species on In 2 O 3 ‐based catalysts, affecting the hydrogenation behavior of formate intermediates and the product distribution. The results illustrate the intrinsic relationship between surface hydrogen atom concentration and methanol synthesis rate in catalytic CO 2 hydrogenation over In 2 O 3 ‐based catalysts. This provides the potential to design selective catalysts for CO 2 hydrogenation by modulating the degree of H‐spillover.

Topology-preserving multilevel tuning of a quasi-BIC vortex microlaser with phase-change Sb2S3 metasurfaces

Dynamic reconfiguration of bound-state-in-the-continuum (BIC) microlasers typically involves mode hopping or angle switching, which compromises mode consistency and beam topology. Here, we demonstrate a phase-change Sb2S3 nanodisk metasurface microlaser that enables nonvolatile multilevel wavelength programming while preserving the same symmetry-protected quasi-BIC lasing mode and surface-normal emission. The device exhibits vertical lasing with a linewidth of ∼0.4 nm and Q-factors exceeding 3000. By laser writing of amorphous, intermediate, and crystalline states, the lasing wavelength is tuned from 881 to 889 nm without optical-mode switching or beam steering. Polarization-resolved far-field measurements together with interference analysis confirm vortex-beam emission with a conserved topological charge (q = −1) throughout the programmed tuning sequence. These results establish Sb2S3 quasi-BIC metasurfaces as a compact platform for programmable structured-light microlasers and integrated photonic systems.

Desymmetrization of Malonic Monoesters and Malonic Acids via Enantioselective Catalytic C(sp ³ )─H Oxidation

ABSTRACT Malonate derivatives are readily available starting materials widely employed in the synthesis of bioactive compounds. Herein, we report a novel catalytic protocol for the direct desymmetrization of malonic acids via enantioselective C(sp 3 )─H bond functionalization. Highly enantioselective (up to &gt;99% ee) γ ‐ and δ ‐ C─H bond lactonization of readily available malonic acid monoesters and malonic acids is achieved, using manganese catalysts and hydrogen peroxide as the oxidant. Owing to the ease and versatility of malonic acid derivative synthesis, combined with the potential post‐oxidation elaboration, this methodology overcomes the inherent lack of reactivity of the electron‐poor C(sp 3 )─H bonds of this class of substrates against electrophilic oxidants to provide straightforward access to a broad range of quaternary stereocenters that can be orthogonally manipulated.

Monolithic transfer of thin-film micro-LEDs via electrochemical etching

We report a scalable, low-damage, and high-throughput process for monolithic transfer of III-nitride micro-LED arrays using selective electrochemical etching and wafer bonding. A highly Si-doped n-GaN sacrificial layer enables rapid and uniform release while preserving device integrity, resulting in atomically smooth lift-off surfaces suitable for subsequent processing. Fully fabricated vertical micro-LED arrays with mesa sizes from 100 × 100 μm2 down to 3 × 3 μm2 are released and transferred to silicon carrier wafers in a single step, maintaining precise spatial registration without conventional laser lift-off or serial pick-and-place methods. Transferred devices exhibit low reverse leakage, uniform current injection and emission, and enhanced optical output due to the thin-film flip-chip architecture, with minimal degradation in spectral performance. This approach provides a promising pathway for the scalable heterogeneous integration of III-nitride devices for micro-displays, optical communications, and sensing applications.