In van der Waals heterostructures hosting the quantum anomalous Hall (QAH) effect, an appropriate band alignment is often needed to prevent extrinsic electronic bands from obscuring the topological gap. However, band alignment in two-dimensional heterostructures is typically regarded as a passive property determined by the material choice rather than an actively tunable degree of freedom. Here, we show that ferroelectric substrates provide a nonvolatile route to engineer band alignment through the surface electrostatic potential generated by ferroelectric polarization. The resulting surface potential shifts the energy levels of adjacent layers while largely preserving their intrinsic band dispersion, thereby enabling the controllable topological phase transitions. Using first-principles calculations, we demonstrate this mechanism in a van der Waals heterostructure composed of a fluorinated MoSe2 monolayer on a ferroelectric In2S3 substrate. Polarization reversal drives a transition of band alignment from type-III to type-I, inducing a phase transition from metallic states to QAH insulating states with a finite topological gap.

Surface-enhanced Raman spectroscopy (SERS) faces challenges in achieving uniform hotspot distribution and reproducible signals due to uncontrollable nanogap variations in conventional metal nanoparticle substrates. We developed a graphene capsule-enhanced Raman spectroscopy (GCERS) strategy that exploits the atomic-layer thickness and mechanical flexibility of graphene to construct a graphene-confined Au nanoparticle (AuNP) composite substrate, thereby enabling controllable hotspot distribution at the structural level. During Au thinfilm dewetting, graphene-mediated confinement prevents the complete coalescence of adjacent AuNPs and stabilizes the nanogaps mainly within the 0.5-1 nm. Using Rhodamine 6G (R6G) as a probe molecule, the minimum detectable concentration of GCERS is 10-22 M, together with good spatial reproducibility, batch-to-batch reproducibility, and 20-day storage stability. Combined finite-difference time-domain (FDTD), molecular dynamics (MD), and density functional theory (DFT) simulations further reveal the multiscale dual-enhancement mechanism of this system. In terms of electromagnetic enhancement, the relatively uniform subnanometer nanogaps generate strong localized electromagnetic fields, while graphene-mediated surface plasmon polaritons (GPPs) effectively expand the spatial distribution of electromagnetic hotspots, increasing the effective hotspot area by 44.5% and thereby enlarging the active enhancement region of the substrate. In terms of chemical enhancement, graphene not only improves the adsorption stability of R6G and facilitates efficient interfacial charge redistribution among graphene, AuNPs, and R6G, but also assists molecular enrichment toward the strongest electromagnetic nanogaps, thereby increasing the probability of effective molecular detection. Furthermore, the flexible GCERS film can be detached and applied to complex surfaces, demonstrating great potential for trace detection in environmental, food safety, and biomedical applications.

Aza-ortho-quinone methides (ao-QMs) are highly reactive intermediates that have emerged as versatile four-atom synthons for constructing nitrogen heterocycles via cycloaddition reactions. Employing density functional theory (DFT) calculations and a suite of wave function analysis methods, this work systematically elucidates the reaction pathways and regioselectivity of the [4 + 2] cycloaddition between the ao-QMs and ethynyl methyl ketone (AAE). The results show that the whole reaction includes the cycloaddition and aromatization stages. The cycloaddition stage belongs to a classical synergistic mechanism. The aromatization stage is a stepwise mechanism involving initial extraction of the acidic hydrogen by 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), followed by N-S bond cleavage, which is the origin of the regioselectivity. In addition, the Fukui function, average local ionization energy (ALIE), and molecular electrostatic potential (ESP) analysis confirm that the high electrophilicity of the acidic hydrogen in the key intermediate drives the DBU attack. The activation strain model and energy decomposition analysis further reveal that the pathway leading to the 2-substituted quinoline product exhibits stronger orbital interactions and more favorable noncovalent interactions. The regioselectivity is governed by an aromatization-driven reaction mode. Collectively, this work provides an in-depth understanding of the reaction mechanism and regioselectivity of [4 + 2] cycloaddition between ao-QMs and AAE.

The interaction between electrons and phonons in two-dimensional van der Waals materials governs their crucial physical properties. Here, we study the intra- and interlayer electron-phonon (el-ph) interaction of bilayer graphene (BLG) using isotope-labeled Raman spectroscopy. Results show that the G, R and R' peak of BLG with different twisted angles all originate from the intralayer el-ph interaction, in which the resonance of G and R peaks are both related with the intralayer electronic transition connecting the van Hove singularities in the density of electronic states, while the resonance of R' peak are driven by the double resonance condition. And three peaks with different dispersions appear around 3170 cm-1 in BLG with certain twist angles, which are assigned as the 2G, G + R' and 2R' peaks that all from the interlayer el-ph interaction. Our findings facilitate a better understanding of el-ph interaction in the BLG system.

Electric fields play a pivotal role in renewable energy technologies and are essential for enabling a sustainable future. However, the regulation of macroscale catalytic behavior by electric fields has not been well digitally understood yet, as conventional computational models rely on reaction energy profiles that overlook the nonlinear effects of electric fields on elementary reaction steps. Here, we use advanced constant-potential microkinetic simulations to revisit the electrochemical nitrogen reduction reaction (eNRR) under operating conditions, which makes it possible to explicitly integrate both electrochemical and chemical steps and quantitatively predict the effects of electric fields on eNRR macroscale performance. The theoretical activity trends for different metals were successfully reproduced with our model, which are in good qualitative agreement with experimental observations. Furthermore, we propose a new theoretical protocol for eNRR catalyst screening, where an optimal catalyst should exhibit overwhelming N2 adsorption ability over a wide potential range to sufficiently facilitate eNRR at high potentials. Interestingly, the rate-determining step undergoes dynamic evolution with potential variations, with chemical steps imposing fundamental constraints on practical ammonia (NH₃) electrosynthesis. Microkinetic simulations demonstrate that incorporating *NH₃ desorption steps can alter reaction rates by orders of magnitude, highlighting their critical yet often overlooked role. This work establishes a quantitative framework for achieving accurate, physically realistic theoretical simulations in heterogeneous electrochemistry.

Developing microsystem-based tactile sensors that can simultaneously decode multidirectional forces and precise contact locations remains a formidable challenge, limiting robotic dexterity and human-machine interaction. To bridge this gap, we present HexaTouch, a fingertip-scale (15 × 15 × 8 mm) sensor that synergizes the deformation-encoding principle of vision-based sensors with the miniaturization and rapid response of capacitive sensing. The core is a bioinspired bilayer elastomer monolithically incorporating a graded micropillar array, which creates spatially heterogeneous stiffness to enhance sensitivity and load tolerance while generating rich deformation patterns in response to mechanical stimuli. These local deformations are directly transduced into high-resolution capacitive images via a dense capacitive micro-array. A dedicated machine learning framework decodes these images into six-axis force/torque vectors (Fx, Fy, Fz, Mx, My, Mz) and three-dimensional contact coordinates (x, y, z). Experimental results demonstrate exceptional performance, with force measurement errors under 1.6%, contact localization precision of up to 0.1 mm, and inference latency of only 1.5 ms. The system maintains high stability across 0-40 °C and 40-90% relative humidity, with mechanical robustness confirmed through 10-day cumulative cyclic loading tests. The versatility of this sensing system is further validated through extensive applications, including dexterous grasping with stability assessment, precise peg-in-hole assembly under misalignment, and intuitive human-machine interaction in drone flight control and virtual gaming. HexaTouch therefore provides a robust, adaptable micro-tactile sensing platform that significantly advances robotic manipulation and environmental interaction.

How the interfacial thermal conduction of bilayer graphene (BLG) is affected by the interlayer coupling strength has not been fully elucidated yet. This study explores the influence of interlayer coupling on the in-plane and interfacial thermal properties of BLG. Four types of isotope-labeled BLG samples-transferred, annealed, twist, and AB-stacked-are fabricated, and Raman spectroscopy and non-equilibrium molecular dynamics (NEMD) simulations are employed to investigate their thermal conductivities. The results show that as the interlayer coupling strength increases, the interfacial thermal conductance (G) of BLG gradually rises as well. Compared with transferred BLG, an annealing operation leads to a 74.2 % increase in G values, and twist BLG and AB-BLG show approximately four and five times increases, respectively. In contrast, the in-plane thermal conductivity (K) changes nonlinearly. NEMD simulations further reveal that stronger interlayer coupling leads to a greater reduction in K while linearly enhancing G. The vibrational density of state analysis indicates that interlayer coupling increases phonon scattering in the in-plane direction and promotes the contribution of low-frequency phonons to thermal conduction across the interface. These findings deepen the understanding of graphene's thermal properties and offer valuable guidance for optimizing the thermal management applications of 2D materials.

Well-defined subnano-sized metal clusters are highly susceptible to changes in the type, number and arrangement of the metals. Precise alloying and stereocontrol of metal clusters at the atomic level are therefore expected to elucidate unexplored structures and functions. Here, we report an asymmetric alloying method by adding silver trifluoroacetate to a highly symmetric C-centered hexagold(I) cluster protected by triphenylphosphine, and provide detailed descriptions of the structure and propertied of the resulting chiral-at-carbon hexasilver(I)-alloyed tetragoldmethane, CAuI4AgI6, in a bicapped square antiprism. Theoretical calculations reveal the bonding natures of C-AuI bonds and C···AgI interactions. By using homochiral carboxylate ligands, asymmetric induction to (R,Ʌ)- or (S,∆)-CAuI4AgI6 species is quantitatively achieved, each of which exhibits red to near-infrared phosphorescence and distinct chiroptical activity. This asymmetric silver(I)-alloying involves etching of gold(I) ions from the hexagold(I) cluster, which will further lead to the development of heterometal ion clusters as chiral luminescent materials.

The modulation of ferromagnetic order in 2D carbon materials has attracted increasing attention for the development of next-generation spintronic devices and multifunctional information storage technologies. In particular, the graphdiyne (GDY) family has been regarded as more suitable for spintronics owing to its tunable electronic structure and intrinsic semiconductor behavior. However, the effective magnetic introduction methods and their applications in specific devices have always been a challenge for the development of such materials. Here, this study presents a nitrogen-substituted derivative of GDY, triphenyl-substituted triazine graphdiyne (TPTG), as an ideal platform for inducing transition-metal iron (Fe) atoms to modulate the electronic state, resulting in the coexistence of room-temperature ferromagnetism and a semiconductor energy band. Subsequent spin-polarized density functional theory calculations further reveal that the observed ferromagnetism arises from pronounced localized magnetic moments together with electron transfer between carbon atoms and Fe ions. Moreover, by employing a transfer strategy suitable for this material system, thin films were successfully transferred onto a silicon substrate to construct an Fe-doped TPTG-based electronic device. Such a device exhibits typical artificial synaptic behavior under optical stimulation and demonstrates nonvolatile memory characteristics after illumination is removed, enabling the transition from short-term plasticity (STP) to long-term plasticity (LTP). The coexistence of ferromagnetism and semiconducting properties not only makes GDY-based materials promising candidates for exploring physical phenomena but also offers opportunities for the development of carbon-based neuromorphic devices.

The evolution of a solid interface from coupling to friction and its mechanisms still face challenges. Here, we use large-twist-angle bilayer graphene combined with isotope-labeling-assisted Raman spectroscopy to measure the mechanical behaviors of its two layers from coupling to friction. Results show that as the strain of the bottom graphene layer increases, the interfacial interaction gradually weakens from the edge region and finally achieves the superlubricity state. A modified multi-adhesive shear-lag model is established based on the experiments, and its numerical analysis supports the experimental data. Molecular simulations demonstrate that after a critical strain, the interfacial force of large-twist-angle bilayer graphene decreases rapidly to enter the multiple adhesive state and finally stabilizes for friction, attributed to the generation and movements of interfacial dislocations, which reduce the interfacial interaction and promote the layer sliding.

Abstract A solid-state visible-to-ultraviolet triplet–triplet annihilation-based photon upconversion system driven by low-intensity light at sunlight levels is developed. Realizing such a solid-state photon upconversion system has been challenging because it is difficult to achieve high fluorescence quantum yield and fast triplet exciton diffusion simultaneously, which requires methodologies to precisely control interactions among chromophores and suppress quenching of both singlet and triplet excited states. Here, we report that a group of dihydroindeno[2,1-a]indene derivatives functionalized with alkyl chains above and below the π-plane satisfies all these requirements. Among three derivatives investigated, we identify the optimal emitter structure that exhibits the highest photon upconversion quantum yield in both solution and crystalline states. The solid-state system is less affected by crystalline defects, exhibiting high photoluminescence quantum yield, long triplet lifetime, and fast triplet diffusion, with an absolute photon upconversion quantum yield of 1.9% and a low threshold excitation intensity of 1.2 mW cm−2.

Atomically precise silver nanoclusters (AgNCs) offer unique opportunities to correlate structure and photophysical properties, yet enhancing their photoluminescence emission remains challenging due to dominance of non-radiative decay pathways. Here, we report a ligand-engineering strategy to modulate the optical properties of high-nuclearity Ag-56 NCs. The synthesized two NCs, Ag56S12(tBuS)(20)(CF3CO2)(12)(MeCN)(3) (NC-I) and Ag56S12(tBuS)(20)(nBuSO(3))(12) (NC-II), possess a similar hexagonal-close-packed Ag-14 kernel, which is encapsulated by a similar icosahedral S-12 middle-shell and an outer Ag-42 shell, but differ in overall symmetry and outer Ag-ligand shell connectivity. Replacement of bidentate CF3CO2- with tridentate nBuSO(3)(-) ligands increases overall Ag-X (X = O, S, and Ag) bonding interactions, resulting in not only a more rigid and compact outer Ag-42 shell structure but also contraction of cationic Ag-14 core and anionic icosahedral S-12 middle-shell. These structural modifications enhance radiative decay and suppress non-radiative pathways, leading to a 17-fold increase in photoluminescence quantum yield and extended average emission lifetime. Computational analysis confirms that ligand-induced geometric stabilization and electronic delocalization govern the excited-state dynamics. This work demonstrates that rational ligand design can synergistically tune cluster geometry, rigidity, and electronic structure, providing a general strategy to improve the photophysical performance of high-nuclearity AgNCs.

Electrocatalytic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) offers a sustainable route to bio-based polymer monomers, yet its efficiency is constrained by sluggish adsorption and proton-coupled electron transfer (PCET) kinetics. Herein, we report a composite catalyst comprising amorphous RhOx anchored on cobalt-deficient Co3O4 (RhOx-Vco) that synergistically optimizes both thermodynamics and kinetics. Combined experiments and theoretical calculations unveil that RhOx and Co defects collaboratively upshift the d-band center of Co and create Rh/Co dual sites, cooperatively enhancing HMF and OH- adsorption. Concurrently, this strengthened OH- adsorption guides preferential parallel alignment of interfacial water molecules, fostering a highly connected hydrogen-bond network that accelerates PCET kinetics. Benefiting from this multi-level synergy, RhOx-Vco achieves a seven-fold higher current density at 1.40 V than pristine Co3O4, along with a high FDCA yield of 95.8% in three-electrode system. Remarkably, when integrated into a membrane electrode assembly flow electrolyzer, the system maintains excellent performance with 93.4% FDCA yield, 85.6% Faradaic efficiency, and robust cycling stability, demonstrating its practical viability. This work establishes a design paradigm integrating defect and interface engineering to coordinately regulate multi-step reaction processes, offering broad insights for advancing biomass and PCET-related electrocatalysis.

ABSTRACT Luminescent chiral metal clusters represent promising materials for circularly polarized luminescence (CPL). However, assembling clusters exhibiting both robust photoluminescence (PL) and a high dissymmetry factor (| g lum |) through conventional bottom‐up synthesis remains challenging. A straightforward approach is the enantioresolution of structurally well‐defined racemic clusters that demonstrate intense PL. By meticulously selecting chiral oxygen donor ligands and incorporating them into carbon‐centered Au 6 Ag 6 and Au 6 Ag 5 clusters, which are known to possess twisted yet racemic structures and near‐unity PL quantum yields (PLQYs) in solution, we successfully isolated three pairs of enantiopure clusters that display brilliant CPL. Notably, the phosphate‐protected C@Au 6 Ag 6 displayed a high PLQY (0.93) and a significant | g lum | (0.008) in solution, surpassing the performance of C@Au 6 Ag 6 with carboxylate and C@Au 6 Ag 5 with sulfonate. Structural analysis coupled with theoretical calculations indicates that both the compact geometry and the localized orbital distributions within the chiral metal framework contribute to the elevated PLQY and considerable CPL observed in C@Au 6 Ag 6 with phosphate. Finally, we assembled metal cluster‐liquid crystal devices exhibiting enhanced CPL for an information encryption demonstration. This research introduces a series of clusters demonstrating notable CPL, with emphasis on chiral oxygen donor ligands, and proposes a straightforward and promising strategy for efficient fabrication of CPL materials.

Chemical molecules may show very different properties in the solid state and in solution, which is mainly caused by the difference in structure between different physical states. Well-defined metal cluster molecules are ideal models for the investigation of the dynamic dissolution/crystallization process, as they usually exhibit photoluminescence (PL) that is sensitive to reversible changes in coordination geometry and multi-electron structure. Here we report the dissolution/crystallization-induced photoluminochromism (PLC) of carbon-centered AuI 6CuI 2 clusters bearing pyridylphosphine or pyridyl N-heterocyclic carbene (NHC) ligands. These clusters, with an octahedral structure doubly capped with copper(I), exhibit greenish-yellow emission in the solid state. Remarkably, the PL of the NHC-protected clusters in solution changes only slightly, whereas the phosphine-protected clusters exhibit red PL accompanied by a large bathochromic shift (>100 nm), a reversible process upon dissolution equilibration. X-ray absorption spectroscopy and theoretical calculations suggest that the octahedral CAuI 6 structure in the crystal is twisted into a triangular prismatic structure in solution. This remarkable ligand effect on the dissolution/crystallization-induced PLC would provide advanced design guidance for stimuli-responsive chromic materials.

It is essential to develop stable, visible-light photocatalysts that efficiently convert solar energy into fuel. Including a co-catalyst in a heterojunction structure can increase hydrogen production efficiency. The objective of this study is to perform an in situ coupling of Pt onto the 2D/CN/rGO heterojunction using self-assisted sonication and chemical reduction in order to achieve a ternary heterojunction, 1D/2D/2D Pt/CN/rGO. As CN contains abundant amino groups and nitrogen defects, it forms a tightly integrated structure with oxygencontaining groups on rGO, while nitrogen lone pairs interact with PtNPs to improve their dispersion. As a result, rGO acts as a conductive bridge, and plasmonic metals extend light absorption into the visible and nearinfrared regions. Through stacking between aromatic triazine rings, the synergistic effects within CN/rGO reduce interplanar spacing, thereby increasing electron transfer and reducing charge recombination, enhancing catalytic activity. In comparison to CN, binary PCN, and RCN-3, the 1D/2D/2D Pt/CN/rGO (RPCN-2) ternary heterojunction demonstrated the highest hydrogen production (H2) of 957 & micro;mol g- 1 h- 1. In addition to creating advanced heterojunction-based materials with optimally integrated co-catalysts, this research also provides a strategic approach to interfacial engineering to address energy and environmental challenges.

The electrocatalytic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) is a pivotal route for biomass valorization but faces dual challenges: weak HMF adsorption and severe competitive adsorption with OH-. Herein, we report a MoOx-decorated defective CoFe-layered double hydroxide (MoOx-Ov-LDH) fabricated via a defect-creation-defect-filling strategy. This design integrates complementary functions: oxygen vacancies enhance HMF adsorption, while the MoOx decoration process further proliferates defect sites to strengthen HMF binding and simultaneously provides Lewis acid sites for preferential OH- adsorption. This creates spatially segregated adsorption sites for HMF and OH-, effectively mitigating competitive adsorption. Consequently, MoOx-Ov-LDH delivers outstanding performance: a low potential of 1.38 V at 50 mA cm-2 and a 95.0 ± 1.7% FDCA yield in a three-electrode system, and under simulated industrial flow electrolysis, achieves 93.7 ± 2.2% FDCA yield with 90.4 ± 2.1% Faradaic efficiency and stable operation over twelve cycles. This work establishes a site proliferation and function separation paradigm for rationally designing electrocatalysts for complex reaction networks in biomass conversion.