Lead-based halide perovskites have revolutionized optoelectronic technologies, yet their commercialization is hindered by lead toxicity and environmental instability. Zero-dimensional (0D) lead-free halide perovskites, featuring isolated metal halide clusters and tunable...

Two-dimensional (2D) semiconductors possessing strong spin-orbit coupling (SOC) and nontrivial topological features are central to the development of energy-efficient spintronics. While Weyl physics is extensively studied in semimetals, its realization in atomically thin semiconductors remains limited. Using first-principles calculations, we identify layered SnP2Se6 as a versatile topological semiconductor platform. In its monolayer form, the intrinsic structural chirality gives rise to a coexistence of Ising-type and Weyl-like (the properties of this material cannot be fully characterized as those of Dirac or Weyl materials) SOC. The latter is characterized by radial hedgehoglike spin textures-a signature of unique manifestation of Weyl-type SOC in a 2D chiral lattice within a 2D semiconductor-resulting in a significant intrinsic spin Hall conductivity (SHC) of up to 10.2 (hi/e) S/cm. In multilayer SnP2Se6, symmetry evolution facilitates a distinct regime where Weyl-like and Rashba spin textures coexist. This transition preserves substantial spin-charge conversion efficiency while introducing chirality-switchable components to the SHC tensor, providing a layer-dependent degree of freedom for spin manipulation. The interplay between strong SOC, topological band features, and structural chirality establishes SnP2Se6 as a platform for thickness-engineered spintronic devices.

Two-dimensional (2D) layered materials lacking inversion symmetry are promising candidates for nano-electromechanical and electronic technologies. Building upon the experimentally synthesized SnP Se crystal, we 2 6 computationally propose a novel series of inherently asymmetric group-IV V-VI semiconductors through elemental substitution. This series encompasses monolayers of SiP2 Se6 , SiAs2 S6 , SiAs2 Se6 , SiAs2 Te6 , GeP2 S6, GeP2 Se6 , GeAs2 S6 , GeAs2 Se6 , GeSb2 S6 , SnP2 S6 , SnP2 Se6 , SnAs2 S6, SnAs Se , SnAs Te and SnSb S . All these structures exhibit robust 2 6 2 6 2 6 energetic and dynamic stability, along with excellent resistance to oxidation when exposed to air. These monolayers have moderate bandgaps ranging from 1.04 to 2.36 eV; notably, the monolayers of SiAs2 Se6 , SiAs2 Te6, GeP S , GeAs Se and SnAs Te are direct-bandgap semiconductors. 2 6 2 6 2 6 More importantly, these group-IV-V-VI monolayers exhibit significant in plane piezoelectricity, with coefficients (d11) as high as 22.94 pm/V. Additionally, SnP Se bilayer exhibit significant out-of-plane piezoelectricity 2 6 (d33) with coefficients exceeding 5 pm/V. Moreover, the coexistence of room-temperature ferroelectricity in these monolayers is unambiguously confirmed by their intrinsic spontaneous polarization and remarkably low ferroelectric switching barriers. These findings establish a new paradigm for integrating piezoelectricity and ferroelectricity with diverse 2D materials, thereby opening exciting opportunities for designing multifunctional materials and developing novel electronic devices.

Rare-earth-based metal halides have emerged as promising alternatives to lead-based perovskites owing to their diverse lanthanide compositions, high structural tunability, and versatile optoelectronic properties. However, their practical development has been hindered by complex synthetic procedures and poor humidity stability. Here, we introduce an organic-inorganic A-site dual-cation hybrid strategy to address these challenges and report a family of stable lanthanide-based metal halides with the general formula (DFPD)2CsLnCl6 (DFPD = 4,4-difluoropiperidine; Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb). Incorporation of Cs+ ions increases lattice rigidity, enhancing moisture and thermal robustness and regulating octahedral distortion. Such structural modulation enables efficient ns 2 ion-mediated sensitization, yielding near-unity photoluminescence efficiencies without perturbing the characteristic f-f emissions of the lanthanide centers. Building on this framework, configurational entropy engineering at the B sites affords three high-entropy rare-earth-based metal halides that preserve the optical signatures of individual lanthanide ions and enable customizable multimodal luminescence spanning the ultraviolet, visible, and near-infrared regions. This work establishes a new class of rare-earth-based hybrid metal halides and provides a general design strategy for the controllable synthesis of multimodal, high-entropy luminescent materials for ultraviolet sterilization, solid-state lighting, and near-infrared imaging applications.

Aqueous batteries attract attention due to their cost-effectiveness, high safety, and environmental friendliness. In aqueous systems, multivalent cations show higher capacity and energy density than monovalent ones. To gain insight into the initial hydration of Mg2+, we investigated Mg2+(H2O)n (n = 1-10) clusters using a comprehensive genetic algorithm and density functional theory. The results show that the Mg2+-water distance increases with n, the coordination number stabilizes at six, and additional water molecules have minimal impact. Binding-energy and charge analyses reveal a transition from strong ion-water interactions to hydrogen-bond stabilization. This work clarifies the atomic-scale hydration mechanism of Mg2+.

Excitons play a central role in optoelectronic, quantum-information, and energy conversion processes, and understanding their radiative recombination behavior is essential for exciton regulation in low-dimensional materials. Here, we employed density functional theory and many-body perturbation theory within the GW-Bethe-Salpeter equation (GW-BSE) framework to systematically investigate the quasiparticle and excitonic properties of a-C36-2D monolayers and SnXY/a-C36-2D heterostructures. The a-C36-2D monolayer exhibits pronounced excitonic effects, with an exciton binding energy of 1.01 eV and bright- and dark-exciton radiative lifetimes on the order of 10-14 and 10-7 s, respectively. Upon heterostructure construction, the exciton binding energies are reduced due to type-II band alignment-induced electron-hole separation and the additional dielectric screening introduced by the SnXY layers. Meanwhile, different SnXY terminal configurations provide an effective approach for tuning bright-exciton radiative lifetimes by regulating transition dipole strengths, enabling lifetime modulation from the 10-12 to 10-11 s range. Furthermore, the reduced interfacial symmetry relaxes parity-related dipole selection rules, leading to finite oscillator strengths of originally dark excitons and shortening their radiative lifetimes from the 10-7 s level to the 10-9 s level. These radiative lifetimes are evaluated from oscillator strengths and transition dipole moments obtained from GW-BSE calculations and therefore characterize the intrinsic radiative recombination of the excitons rather than their total population decay. The combination of large exciton binding energies and broadly tunable radiative lifetimes provides microscopic insight into exciton regulation in fullerene-based two-dimensional heterostructures.

Photoinduced electron transfer (PeT) represents a fundamental mechanism in the design of fluorescent probes and molecular switches, typically modulated by tuning the electronic donating or withdrawing capacity of substituents. This widely adopted strategy implicitly assumes that substituent electronic effects directly translate into effective electronic coupling. Through density functional theory (DFT) and time-dependent DFT (TD-DFT) investigations, we demonstrate that this assumption is insufficient for 1,8-naphthalimide (NI) derivatives. Our results reveal that the occurrence of PeT is not governed by intrinsic electron-donating or -withdrawing ability, but rather by a simple geometric criterion: the coplanarity between the substituent and the NI core. Coplanarity activates π-conjugation between the substituent and the fluorophore, which redistributes π-electron density and attenuates the electron-accepting capacity of the NI unit, thereby suppressing PeT. In contrast, non-coplanar substituents block π-conjugation and facilitate PeT regardless of their intrinsic electronic properties. Notably, we clarify that the experimentally observed pH-dependent fluorescence enhancement originates from deprotonated anionic species rather than neutral forms. Overall, the research calls for a reassessment of conventional PeT-based molecular design strategies and provides a simple, predictive framework for the rational development of PeT-controlled luminescent materials and fluorescent probes.

Reversible control of structural phase transitions and luminescence remains a key challenge in organic-inorganic hybrid metal halides for stimuli-responsive photonic applications. Here, we report two new zero-dimensional (0D) Cd-based metal halides, (DFPD)6CdCl8 and (DFPD)2CdCl4·H2O (DFPD+ = 4,4-difluoropiperidine), in which Sb3+ doping enables distinct emission behaviors governed by coordination geometry. Combined spectroscopic studies and theoretical calculations reveal that Sb3+-doped (DFPD)6CdCl8 exhibits yellow emission with a large Stokes shift arising from triplet self-trapped exciton (3STE) emission, whereas Sb3+-doped (DFPD)2CdCl4·H2O displays excitation-dependent emission due to competing singlet STE (1STE) and 3STE states. This contrast originates from the different Cd-Cl coordination environments (octahedral vs. tetrahedral), which modulate the energy levels and transition dipole moments. Importantly, hydrochloric acid (HCl) and 4,4-difluoropiperidine induce fully reversible interconversion between the two structures, allowing dynamic switching between yellow and deep-orange emission. Based on this reversible luminescence, we further demonstrated applications in dynamic anti-counterfeiting and multilevel information encryption. This work establishes a coordination-structure-driven strategy for programmable emission in 0D hybrid metal halides.

Integrating pronounced spin-orbit coupling (SOC) with broken inversion symmetry opens unprecedented routes to spintronic functionalities. As an alternative to atomic crystal, cluster assembly allows functional materials with tailored properties to be created through precise structural design. Here, motivated by the successful synthesis of Re6Se8 clusters, we computationally design a series of one-dimensional (1D) nanowires—Re12S12Cl10, Re12Se12Cl10, Re12S12Br10, Re12Se12Br10, Mn12Se12Cl10, Mn12S12Cl10, Mn12S12Br10 and Mn12Se12Br10—self-assembled from M6X6A6 clusters (M = Mn, Re; X = S, Se; A = Cl, Br) via covalent linkages. These nanowires feature a helical screw dislocation that intrinsically breaks inversion symmetry, serving as the structural origin for SOC-induced spin textures. Our density functional theory calculations demonstrate that the Re-based systems exhibit pronounced Rashba SOC splitting, while the Mn-based systems host substantial Dzyaloshinskii–Moriya interactions, alongside robust energetic, thermal, and dynamic stability. This work demonstrates the structural feasibility of cluster-assembled 1D nanomaterials and highlights their enhanced property tunability compared to conventional atomic crystals. M12X12A10 nanowires, self-assembled from M6X6A6 clusters (M = Mn, Re; X = S, Se; A = Cl, Br), feature an intrinsic screw dislocation that breaks inversion symmetry. First-principles calculations reveal pronounced Rashba splitting in Re-based and strong Dzyaloshinskii–Moriya interactions in Mn-based systems, enabling spintronic applications.

Room-temperature spin-optoelectronic devices require a combination of robust ferromagnetism and giant exciton binding, a pairing mutually exclusive in conventional semiconductors due to magnetic localization that screens excitons. Cluster-assembled V4S9X4 (X = F, Cl, Br and I) monolayers overcome this bottleneck via a hierarchical design, that is, intra-cluster localized states host both local magnetic moments and strong electron-hole interactions, while inter-cluster coupling mediates long-range ferromagnetism. Remarkably, these two-dimensional semiconductors exhibit intrinsic ferromagnetism with Curie temperature up to 507.6 K. As a prototype, V4S9Br4 monolayer possesses a giant exciton binding energy of 1.85 eV. Its lowest exciton is a dark state (DI) with a radiative lifetime of 1.20 ns, whereas the first bright exciton (BI) exhibits an ultrafast radiative decay of 86.87 ps. This stark lifetime contrast enables simultaneous ultrafast optical response and long-lived spin information storage. Most notably, switching between ferromagnetic and antiferromagnetic order allows for wide-range tuning of exciton lifetime, with the giant binding energy remaining nearly intact. Our findings establish cluster assembly as a powerful paradigm for designing next-generation spin-photonic and quantum information devices operating at room temperature.

Chemical mechanical polishing (CMP) of SiC is fundamentally limited by its high hardness and chemical inertness, as well as the pronounced polarity-dependent anisotropy between the Si-face (0 0 0 1) and C-face (0 0 0 -1). In this work, the intrinsic mechanism governing polarity-dependent oxidation and material removal of 4H-SiC is systematically investigated by combining CMP experiments, surface characterization, electrochemical analysis, and first-principles calculations.Under identical polishing conditions, the C-face exhibits a significantly higher material removal rate (1900 nm center dot h- 1) and lower surface roughness (0.13 nm) compared to the Si-face (1000 nm center dot h- 1, 0.65 nm). Electrochemical results reveal faster oxidation kinetics on the C-face, which is further confirmed by the formation of a thicker oxide layer and enhanced oxygen-containing species. DFT calculations demonstrate that the C-face possesses higher surface energy, lower work function, and stronger charge transfer capability, leading to more favorable oxidant adsorption and interfacial reactions. These results reveal that the superior CMP performance of the C-face originates from its intrinsically enhanced electronic activity and oxidation-assisted removal capability. This work establishes a clear structure-property-performance relationship for polarity-dependent CMP of SiC and provides new insights for improving polishing efficiency and achieving wafer-level uniformity.

Chemical mechanical polishing (CMP) of SiC is fundamentally limited by its high hardness and chemical inertness, as well as the pronounced polarity-dependent anisotropy between the Si-face (0 0 0 1) and C-face (0 0 0 −1). In this work, the intrinsic mechanism governing polarity-dependent oxidation and material removal of 4H-SiC is systematically investigated by combining CMP experiments, surface characterization, electrochemical analysis, and first-principles calculations.Under identical polishing conditions, the C-face exhibits a significantly higher material removal rate (1900 nm·h−1) and lower surface roughness (0.13 nm) compared to the Si-face (1000 nm·h−1, 0.65 nm). Electrochemical results reveal faster oxidation kinetics on the C-face, which is further confirmed by the formation of a thicker oxide layer and enhanced oxygen-containing species. DFT calculations demonstrate that the C-face possesses higher surface energy, lower work function, and stronger charge transfer capability, leading to more favorable oxidant adsorption and interfacial reactions. These results reveal that the superior CMP performance of the C-face originates from its intrinsically enhanced electronic activity and oxidation-assisted removal capability. This work establishes a clear structure–property–performance relationship for polarity-dependent CMP of SiC and provides new insights for improving polishing efficiency and achieving wafer-level uniformity.

Rational design of efficient electrocatalysts to regulate sulfur redox kinetics is crucial for inhibiting "shuttle effect" in practical Li-S batteries under high sulfur loading and lean electrolyte conditions. Herein, we synthesize a nitrogen-coordinated porous carbon supported FeCo diatomic catalyst as a bifunctional sulfur host. Fe and Co centers exhibit asymmetric electron distribution and synergistic interactions, enabling selective acceleration of sulfur reduction at Fe sites and Li2S oxidation at Co sites. Combined experimental and theoretical analyses collectively validate this bifunctional catalytic mechanism, which significantly improves sulfur redox reversibility and inhibits polysulfide shuttling. Consequently, the FeCo DA-NC based Li-S coin cells deliver ultra-high sulfur utilization (1616 mAh g-1 at 0.1 C), superior rate capability (912 mAh g-1 at 2 C) and stable cycling (714 mAh g-1 after 500 cycles at 1.0 C). Even under harsh conditions (7.8 mg cm-2, E/S = 5.0 & micro;L mgs -1), 83.3% capacity retention is maintained after 100 cycles at 0.1 C. And the FeCo DA-NC based 8 Ah-level Li-S pouch cell achieves a high energy density of 480 Wh kg-1. Overall, this work provides the first demonstration of diatomic catalyst strategy in practical Li-S pouch cells, establishing a viable pathway for future Li-S batteries.

The modulation of molecular excited states and luminescence properties by external electric fields provides a fundamental physical basis for developing tunable optical and quantum functional devices at the molecular scale. In this work, density functional theory (DFT) and time-dependent density functional theory (TDDFT) calculations were employed to investigate the electric-field response of the quantum-confined Stark effect (QCSE) in a covalently [2 + 2] cycloaddition-bridged Sc3N@Ih-C80 endohedral metallofullerene dimer. The results showed that, compared with the monomer, covalent bridging significantly enhances the electric-field tunability of energy levels. In the low-to-moderate field regime, the response is mainly governed by the polarizability term, whereas stronger fields promote electron-hole separation and exciton evolution from a Frenkel to a charge-transfer type. These findings elucidate the underlying physical mechanism of electric-field regulated excited states in assembled endohedral metallofullerene dimers and provide theoretical guidance for the design of molecular-scale optoelectronic and quantum devices.

Ultrafast spin manipulation in low-dimensional magnetic materials is essential for next-generation spintronic devices, yet the microscopic mechanisms governing spin dynamics, especially the role of surface termination, remain unclear. Here, TiCrCT2 (T = O, F) MXenes are systematically investigated using real-time time-dependent density functional theory and nonadiabatic molecular dynamics. The results reveal that surface termination governs distinct magnetic responses, including a ferrimagnetic-to-ferromagnetic transition in TiCrCF2 driven by Ti spin reversal, while TiCrCO2 preserves its ferrimagnetic order. This behavior originates from spin-conserving, spin-selective charge transfer between Ti and Cr sublattices, followed by asymmetric relaxation of spin carriers determined by the spin-resolved band-edge structure. Electron-phonon coupling dominates over spin-orbit coupling, enabling rapid same-spin transitions, whereas spin-flip processes occur on longer time scales. These findings establish a unified mechanism linking electronic structure, carrier relaxation, and magnetization dynamics, and highlight surface termination as an effective route to tailor ultrafast spin responses in MXenes.

Homogeneous electro-Fenton (EF) systems are generally considered to rely on dissolved Fe2+/Fe3+ cycling for H2O2 activation, whereas the possible electrochemically induced dissolved Fe species loading at the cathode has been overlooked. Here, we demonstrate that dissolved Fe species can be progressively immobilized as Fe2O3-like species on an oxygen-doped carbon nanotube-loaded carbon felt cathode (O-CNT/CF) during homogeneous EF process, and converting homogeneous EF reaction to coexisting homogeneous and heterogeneous reaction. The Fe immobilized O-CNT/CF significantly enhances ofloxacin (OFL) degradation with the pseudo-first-order rate constant increasing from 0.176 to 0.230 min−1. Electron paramagnetic resonance (EPR) analysis combined with quenching experiments reveals a time-dependent transition from ·OHfree-dominated homogeneous oxidation to surface-mediated mixed ROS generation involving ·OHsur, ·O2−, and 1O2. Density functional theory calculations further show that oxygen-containing functional groups strengthen Fe binding on the carbon surface and facilitate interfacial H2O2 activation toward *OOH-related intermediates, thereby promoting Fe immobilization and subsequent 1O2 generation. This work demonstrates that the added Fe ions can be immobilized on cathode and induce a heterogeneous reaction during a homogeneous EF system, which provides new insights for rationally designing reusable cathodes for wastewater treatment.

Using high-throughput GGA+U first-principles calculations we survey the formation energy, magnetic ground state and spin-valley-coupled electronic structure of 87 monolayer 2H-phase MX2 (M = Groups-IIIB-IIB, X = S, Se, Te). A systematic group-by-group evolution is uncovered: 3d-based TMDs favor antiferromagnetic (AFM) semiconductors, 4d congeners stabilize ferromagnetic (FM) metals or bipolar magnetic semiconductors (BMSs), whereas 5d members are overwhelmingly non-magnetic metals. Thermodynamic stability (ΔHf ≤ 0) is fulfilled for all sulfides/selenides/tellurides of Groups-IIIB-VIB and most of Groups-VIIB-VIII, whereas post-transition-metal TMDs (Groups IB-IIB) are unstable. Valley polarization is dictated by the interplay between hexagonal lattice symmetry and magnetic order: FM Group-VB VX2 and BMS VSe2/VTe2 exhibit 100% spin-polarized K/K' band edges ideal for the anomalous valley Hall effect, while AFM Group-VIB CrX2 and Mo/WX2 retain spin-degenerate K-point valleys suitable for reversible valleytronics. The resulting atlas provides an experimentally verifiable blueprint for wafer-scale synthesis of high-temperature FM, half-metallic or valley-polarized 2D crystals and accelerates the materialization of next-generation spin-valleytronic devices.

The heterogeneous electro-Fenton process shows high-efficiency organic contaminant mineralization through in-situ H2O2 generation and activation to center dot OH. However, conventional carbon-based electro-Fenton catalysts with iron oxide compounds (e.g. Fe2O3, Fe3O4) face issues like iron leaching and ill-defined H2O2 activation sites. We present a dual-functional catalyst, oxygen-doped carbon spheres embedded with Fe2C nanoparticles (Fe2C@OCS), where Fe2C enhances H2O2 activation to center dot OH based on efficient H2O2 generation on the carbon. This system achieves broad pH adaptability (3-11) for sulfamethoxazole degradation with negligible iron leaching (<0.001 mg L-1). Application to pharmaceutical effluent shows 80.3 % TOC removal, 80.7 % COD reduction, and biotoxicity mitigation. Density functional theory reveals that the Fe2C (111) facet promotes efficient H2O2 activation via optimal OH intermediate adsorption. This work offers a stable, iron-carbide-based catalyst with valuable insights into advanced oxidation processes.

Two-dimensional (2D) ultra-wide bandgap (UWBG) semiconductors are essential for extreme-condition electronics and deep-ultraviolet (UV) optoelectronics, yet their diversity is limited. Here, have established tetrahedral [MCl4]2- clusters (M = Be, Mg, Ca, Sr, Fe, Co, Ni, Zn and Cd) as effective superatomic building blocks for designing a novel family of stable 2D MCl2 monolayers via a bottom-up cluster-assembly strategy. These monolayers exhibit UWBG semiconducting behavior with bandgaps ranging from 3.37 to 6.92 eV (HSE06), placing them alongside h-BN and Ga2O3 as wide-gap materials. They show strong deep-UV optical absorption with coefficients exceeding 105 cm-1, reaching 106 cm-1 for BeCl2 at similar to 140 nm. Owing to their intrinsic non-centrosymmetric C4v structure, these monolayers simultaneously exhibit pronounced out-of-plane piezoelectricity with d31 coefficients up to 31.26 pm V-1 (CoCl2)-comparable to or exceeding many known 2D piezoelectrics-and a mix of Rashba-Dresselhaus spin-orbit coupling with constants alpha R-D ranging from 0.10 to 0.36 eV & centerdot;& Aring; at the Gamma point, significantly larger than that of alpha-In2Se3 (0.097 eV & centerdot;& Aring;). All monolayers are dynamically and thermally stable, with formation energies between -1.03 and -1.89 eV atom-1. Our work establishes that this cluster-assembly approach successfully bypasses many core challenges of top-down fabrication (such as uncontrollable defect proliferation and the resulting performance degradation), enabling the atomically precise fabrication of low-symmetry 2D materials with tailored multifunctional properties for deep-UV optoelectronic and extreme-environment electronic applications.

Heterogeneous electro-Fenton process enables efficient mineralization of organic contaminants by highly oxidative hydroxyl radicals (•OH) generated from electrochemical activation of H2O2 (EAH). Compared with iron nanoparticles, single-atom catalysts (SACs) with isolated Fe-N4 sites offer higher metal utilization, improved structural stability, and enhanced catalytic performance in the EAH process. However, symmetric Fe-N4 sites exhibit suboptimal intermediate adsorption, which limits further enhancement of •OH generation. Herein, atomically dispersed asymmetric Fe-N3C sites were engineered on carbon nanoflowers (FeN3C@CNFs), which exhibit higher •OH generation and more efficient contaminant removal than carbon nanoflowers featuring Fe-N4 sites. Density functional theory (DFT) calculations revealed that the asymmetric Fe-N3C coordination facilitates H2O2 adsorption and O-O bond cleavage, thereby lowering the energy barrier for •OH formation. The FeN3C@CNFs-catalyzed system exhibited effective treatment performance toward actual pharmaceutical wastewater, reducing TOC from 94.0 to 34.1 mg L-1 and COD from 265.9 to 81.3 mg L-1, meeting the discharge standard of water pollutants for pharmaceutical industry chemical synthesis products category (GB 21,904-2008, China) and further confirming the pivotal role of •OH-driven oxidation. This work highlights the critical role of atomic coordination in boosting •OH electro-generation for wastewater treatment.