Constructing two-dimensional heterostructure is an efficient approach for realizing fascinating properties and playing a key role in solar energy-driven water decomposition schemes. Based on the first-principles calculations with the HSE06 functional, we reveal the intriguing potential of two-dimensional GaO/ZnO heterostructure for optoelectronic applications, including photocatalysis and light-harvesting devices. The results show that the AAstacked GaO/ZnO heterostructure is dynamic, mechanical and thermal stable. The heterostructure exhibits a type-II band alignment, characterized by a direct band semiconductor with the band gap of 0.348 eV. Furthermore, the band edges are in proper energetic positions to provoke the water redox reaction to generate hydrogen and oxygen. Analysis from the electrostatic potential and the charge density difference show that the built-in electric field is formed at the interface, which could facilitate the separation of photogenerated carriers in the GaO and ZnO layers, improving significantly the photocatalytic activity. There are about amount of electron about 0.0746 e transfer from ZnO layer to GaO layer. The maximum absorption spectrum of the heterostructure within the visible light region reaches up to 0.415 x 10(5) cm(-1), which is conducive to improving the photocatalytic performance of the two-dimensional heterostructure. Additionally, the band structure of GaO/ZnO heterostructure can be effectively tuned via external strain while preserving the type-II band alignment. The current results provide a theoretical basis for the experimental design of the ZnO-based heterostructure in optoelectronic device applications.

Based on first-principles calculations combining density functional theory (DFT) and the Boltzmann transport equation, this study systematically investigates the thermoelectric properties of two-dimensional Nb2XSe2 (X = B, C, N) materials. The electronic structure near the Fermi level exhibits strong hybridization between Nb d-orbitals and X/Se p-orbitals, coexisting with heterogeneous bonding characteristics—polar covalent Nb–Se bonds and delocalized ionic Nb–B/C/N bonds. Phonon transport analysis reveals that, with increasing atomic number of X, the enhanced hybridization between antibonding and bonding states elevates lattice anharmonicity, leading to an increase in the acoustic-mode Grüneisen parameter |γ| from 1.9 to 3.1 and a significant reduction in lattice thermal conductivity from 4.13 to 0.30 W/(m·K). Thermoelectric optimization results demonstrate that p-type doped Nb2CSe2 simultaneously achieves the maximum Seebeck coefficient (-70.4 µV·K− 1) and power factor (13.4 mW·m− 1·K− 2), yielding a peak zT value of 0.92 at room temperature. In contrast, the zT values of all three compounds under n-type doping are approximately 0.04–0.38. The realization of high zT values relies on low lattice thermal conductivity as the foundation, along with the synchronous enhancement of electronic transport properties to achieve a synergistic balance between electron and phonon transport.

Two-dimensional ZnO materials have attracted considerable attention in scientific research and industrial applications due to their special physical and chemical properties. Understanding the structural transformation of few-layer ZnO is a prerequisite for further exploring its the optoelectronic properties. In this work, the layer thickness effects on the phase transition and electronic properties of few-layer ZnO were systematically investigated using the first-principles calculations based on the DFT + U method. Few-layer ZnO transforms from planar structure to 8|4 Haeckelite structure with the layer thickness ranging from 1 to 17, and then reconstructs into wurtzite structure as the layer increases from 18 to 20. The planar-to-Haeckelite-to-wurtzite structural transformation occurs at thicknesses of 11 layers and 18 layers. Moreover, few-layer ZnO with planar structure, 8|4 Haeckelite structure, and wurtzite structure exhibits energetic, mechanical and thermal stability. Few-layer ZnO with planar and 8|4 Haeckelite structures exhibits semiconducting behavior with the calculated band gaps of 2.963 eV and 2.587 eV, respectively. In contrast, few-layer ZnO with wurtzite structure becomes metallic due to the existence of surface states. Strain also can greatly modify the electronic properties of few-layer ZnO with 8| 4 Haeckelite and planar structures. Of special interest is the strain-induced transformation from direct to indirect band gap in the planar structure under available external strain. Our findings provide theoretical guidance for modulating the electronic properties of few-layer ZnO via thickness effects for nanoelectronic applications.

Rational design of low-cost, highly-efficient electrocatalysts for the hydrogen and oxygen evolution reactions (HER/OER) is critical to enable sustainable hydrogen production via water electrolysis. Herein, a novel nanorod array catalyst, Fe-NiMoN, has been rationally designed and directly grown on nickel foam (NF) via a facile hydrothermal method followed by nitridation treatment. The novel 3D porous nanorod architecture is favorable for providing abundant active sites, accelerating mass diffusion/electron transfer, and facilitating gas release. In addition, density functional theory (DFT) simulations reveal that Fe doping shifts the d-band center of NiMoN away from the Fermi level compared to the undoped NiMoN, thereby reducing the hydrogen adsorption free energy (ΔGH*) toward 0, which in turn enhances the HER activity. Consequently, the Fe-NiMoN catalyst delivers exceptional bifunctional electrocatalytic activity in alkaline media, requiring low overpotentials of 17 mV (HER) and 238 mV (OER) to achieve 10 mA cm-2. Notably, the Fe-NiMoN catalyst assembled into a two-electrode alkaline electrolyzer requires a voltage of only 1.504 V to achieve a current density value of 10 mA cm-2, with no performance declining after 100 h of steady operation. Moreover, for urea-assisted electrolysis, it can deliver 10 mA cm-2 at only 1.367 V. Overall, this work provides a strategy for synthesizing desirable electrocatalysts for green hydrogen production coupled with wastewater treatment.

This study comprehensively maps the evolution of neutral PbMgn clusters (n = 2-20), revealing a distinct size-dependent structural evolution from small symmetric frameworks with Pb occupying peripheral sites (n < 10) to large disordered structures with Pb surface-adsorbed on Mg cores (n >= 10). Analysis of relative stability identifies PbMg8 and PbMg18 as exceptionally stable "magic" clusters, evidenced by peaks in binding energy, second-order energy difference, and HOMO-LUMO gaps. The electronic properties are governed by significant electron transfer from Mg to Pb atoms (-0.73e to -2.73e), with Pb 6p orbitals acting as the primary electron acceptors. Crucially, topological investigations unravel the chemical bonding nature, uncovering a dual mechanism: covalent Mg-Mg networks form the structural framework, while ionic Pb-Mg interactions provide electrostatic stabilization. These atomic-scale insights fill a critical knowledge gap and offer a foundation for rationally designing Pb-Mg nanomaterials.

Unstable solid electrolyte interphases and dendritic growth remain critical barriers for sodium metal anodes, especially on industrially viable planar current collectors. Here, a fluorine-containing SnO2 layer is grown directly on Cu foil to construct a sodiophilic current collector that enables stable Na metal deposition. During the early stage of sodiation, the modified collector spontaneously reacts with Na to in-situ generate a NaF-Na2O-Sn composite interphase on the surface of the current collector, contributing to the formation of an inorganic-rich interface with improved interfacial transport kinetics. Systematic structural, interfacial, and electrochemical analyses demonstrate that this coating-derived interphase homogenizes Na nucleation, promotes a more homogeneous interfacial transport environment, and stabilizes the Na/electrolyte interface, thereby effectively suppressing dendritic growth. As a result, the F-SnO2-modified electrodes exhibit low polarization, high Coulombic efficiency, and long-term cycling stability, sustaining 2500 cycles in half cells and over 5600 h in symmetric cells at 1.0 mA cm-2. Furthermore, full and pouch cells paired with Na3V2(PO4)3 deliver enhanced rate capability and durable cycling performance, highlighting the practical potential of this coating-derived interfacial strategy for advanced sodium metal batteries.

The successfully construction of ZnO/MoS2 van der Waals heterostructures has attracted considerable attention. Nevertheless, the fundamental mechanisms underlying its performance in photocatalytic and optoelectronic applications remain insufficiently explored. Here, the geometrical structures and electronic properties of twodimensional ZnO/MoS2 heterostructures, as well as the impacts of biaxial strain and layer thickness on the heterostructures were systematically investigated through the first-principles calculations based on the HSE06 functional. The results demonstrate that the ZnO/MoS2 heterostructure is energetically and dynamically stable. The ZnO/MoS2 heterostructure exhibits an indirect semiconductor with the bandgap of 1.530 eV. Moreover, the CBM and VBM are mainly contributed by the MoS2 and ZnO layers, respectively, indicative of a typical type-II heterostructure. Under the biaxial strain, the ZnO/MoS2 heterostructure first undergoes a transition from a direct type-I to a quasi-type-II, and then to a type-II configuration. When the biaxial strain is from -10% to 2%, the bandgaps of ZnO/MoS2 heterostructures meet the requirements for photocatalytic water splitting. Additionally, the variation in thickness causes the ZnO layer to transition from a planar structure to a wurtzite structure, accompanying a transition from an indirect band gap to a direct band gap. Our theoretical calculations offer insights into the regulation of bandgap by strain or layer thickness in ZnO/MoS2 vdW heterostructure, providing valuable thereotical references for the development of efficient nano-photocatalytic and nano-optoelectronic materials.

Unstable interphase chemistry and spatially nonuniform Na transport jointly limit the reversibility of sodium metal anodes. Here, a fluorinated-carbon-modified Cu current collector was prepared by chemical vapor deposition, and its C-F bonding configuration was regulated through the synthesis temperature. Among the samples investigated, CFx modified Cu prepared at 900 oC contained the highest proportion of semi-ionic C-F bonds and exhibited the lowest Na nucleation overpotential, establishing a correlation between the C-F bonding environment and Na deposition behavior. Depth-resolved XPS, cryo-TEM, and ToF-SIMS revealed a thin inorganic-rich interphase containing NaF and Na2O on CFx modified Cu, in contrast to the thicker, predominantly amorphous interphases formed on C modified Cu and bare Cu. DFT calculations showed that fluorinated carbon strengthened Na adsorption and reduced the surface-migration barrier to 0.0824 eV, favoring Na capture followed by lateral redistribution. COMSOL simulations further illustrated more uniform interfacial current-density and Na+-concentration distributions. Consequently, CFx modified Cu supported compact Na deposition with an enhanced Na(110) preferred orientation. The Na|CFx cell maintained an average Coulombic efficiency of 99.8% for approximately 3700 cycles at 1.0 mA cm-2, while the Na|CFx@Na symmetric cell operated for 4000 h. Improved performance was also retained in Na3V2(PO4)3 full cells and anode-free configurations. These results identify C-F bonding regulation as a viable route for coordinating Na nucleation, surface migration, and interphase evolution.

The thermoelectric properties of two-dimensional M2BS2 (M = Ti, Zr, Hf) materials were investigated in this study by using first-principles calculations. The phonon dispersion indicate that the high-frequency branches are dominated by B vibrations, while the mid- and low-frequency branches are primarily influenced by M and S atoms. All three compounds are confirmed to be dynamically stable. The lattice thermal conductivity is primarily contributed by acoustic and low-frequency optical phonons, with its overall magnitude determined by relaxation times, group velocities, and Grüneisen parameters. The resulting thermal conductivities follow the sequence kl(Ti2BS2) > kl(Hf2BS2) > kl(Zr2BS2), reaching 2.35 W·m-1·K-1, 2.14 W·m-1·K-1, and 2.05 W·m-1·K-1 at room temperature, respectively. Monolayer Hf2BS2 maintains relatively high Seebeck coefficients and power factors under either doping polarity, achieving a peak thermoelectric figure of merit of 1.74 in the n-type configuration. These findings provide a strong theoretical foundation for designing novel, high-performance thermoelectric device materials.

Developing electrode materials that simultaneously deliver high energy density and long-term cycling stability remains a central challenge for supercapacitors. In this work, bimetallic glycerolates (NixMny-Gly) microspheres with tunable microstructure and electrochemical activity are synthesized via compositional control. The optimized Ni2Mn1-Gly electrode achieves a high specific capacitance of 2110 F g-1 and maintaining 90.48% of its capacity after 8000 cycles. Kinetic analysis reveals a predominant diffusion-controlled charge storage mechanism, confirming effective bulk redox activity. Density functional theory (DFT) calculations further confirm that the synergistic Ni/Mn interaction enhances both electrical conductivity and structural stability of the Ni2Mn1-Gly, facilitating charge transfer and redox kinetics. Furthermore, an asymmetric supercapacitor assembled with Ni2Mn1-Gly and activated carbon achieves a high energy density of 117.2 W h kg-1 along with excellent rate capability. This work demonstrates a rational material design strategy toward durable, high-energy super-capacitors through composition-structure-performance synergy.

The identification of intrinsic catalytic activity in electrocatalytic systems remains challenging due to the strong coupling between electronic structure and morphological effects. Here, we constructed a series of ultrafine transition metal nitride nanodots (VN/C, Mo2N/C, W2N/C, and CoN/C) with nearly identical particle sizes and carbon supports via a unified template-assisted chemical vapor deposition strategy, thereby minimizing morphological variations and enabling direct attribution of catalytic performance to intrinsic electronic structure. Replacing the sluggish oxygen evolution reaction with the hydrazine oxidation reaction (HzOR) provides a thermodynamically favorable pathway, while imposing stringent requirements on bifunctional catalysts capable of driving both HER and HzOR. The intrinsic catalytic activities of these nitrides showed clear differentiation, and VN/C exhibited the best bifunctional performance, with overpotentials of 68/133 mV for HER and - 45/125 mV for HzOR at 10/100 mA cm-2. Mechanistic analysis revealed that the near-optimal d-band center of VN enabled balanced adsorption-desorption of reaction intermediates, whereas CoN and W2N/Mo2N were limited by excessively strong and weak adsorption, respectively. This intrinsic advantage extended to the device level, where VN/C enabled low-voltage overall hydrazine splitting and achieved an energy efficiency of 97.9% with stable cycling in a Zn-hydrazine battery.

Magnesium (Mg) metal is a promising alternative to lithium metal anodes, but its practical application is limited by sluggish interfacial kinetics and unstable deposition behavior. Here, we report a SiOC/Sn crystal-amorphous heterointerface, in which nanocrystalline Sn domains are embedded in an amorphous SiOC matrix. Both density functional theory calculations and experimental results reveal that Sn incorporation modulates the interfacial electronic structure, strengthens Mg-substrate interaction, and facilitates charge transfer. This shifts Mg nucleation from aggregation-dominated growth to surface-stabilized spreading, promoting two-dimensional deposition. As a result, the SiOC/Sn host enables uniform and compact Mg deposition with reduced nucleation barriers, improved interfacial kinetics, and enhanced reversibility. The electrode exhibits stable cycling over a wide temperature range and delivers reliable performance in full-cell configurations. This work highlights interfacial electronic structure as a key factor governing Mg deposition and provides insights into the regulation of multivalent metal deposition.

Two-dimensional ZnO materials have recently attracted widespread research attention for their promising properties, chemical stability, and mechanical strength. These special properties make them not only imply a scientific interest but also indicate great technological applications in optoelectronics, photonics, and sensors. Herein, based on the first-principles calculations with the HSE06 potential, the atomic structures and electronic properties of ZnO bilayer with different stacking are investigated. The results demonstrate that AB-stacking is the most energetically favorable configuration among all those considered. The AB-stacking is mechanically and dynamically stable. The calculated band gap is 2.88 eV using the HSE06 potential and 1.45 eV using the PBE potential. Moreover, we found that it is possible to modulate the energy bandgap both by the type of bilayer stacking and by the effect of the biaxial strain and interfacial distance. The ability to tune the energy bandgap in ZnO bilayers by adjusting their geometric configuration or applying an external strain or changing the interfacial distance could inspire new applications in various technological fields.

To meet the current requirements for diluted magnetic semiconductors, it is essential to design the materials with high stability and spin polarization for promoting the development of spintronic devices. Amelioration on the properties of two-dimensional ZnO bilayers for high-performance optoelectronic and spintronic remains a significant challenge and is highly anticipated. Herein, we systematically investigated the electronic structures and magnetic properties of AA-stacked ZnO bilayers through the first-principles calculations, focusing on the effects of covalently bonded F/N-intercalation and the introduction of SiC substrate. The results indicate that pristine ZnO BL, F@ZnO, N@ZnO bilayer and ZnO/SiC heterostructure exhibit dynamical, and mechanical and thermal stability. F@ZnO and N@ZnO exhibit magnetic properties, and the magnetic moments are 0.659 mu B and 1.0 mu B, which are primarily derived from O-2p and N-2p orbitals, respectively. F@ZnO exhibits half-metallic magnetic characteristics, whereas N@ZnO displays metallic features at high intercalation concentrations up to 100%. The stable half-metallicity originates from a spontaneous phase transition driven by Stoner instability due to the high density of states peak near the Fermi level. In ZnO/SiC heterostructure, one of the ZnO layers adjacent to the SiC layer becomes buckled with a height of 0.891 & Aring;, while the other ZnO layer, situated farther from the SiC layer, remains planar. Furthermore, the system undergoes the transition from a nonmagnetic state to a ferromagnetic state due to the introduction of C atoms. These findings provide a new platform for designing 2D magnetic thin films, which could hold potential for enhancing the application of ZnO materials in optoelectronic and spintronic devices.

The practical application of Na metal anode is significantly hindered by uncontrolled dendrite growth and unstable solid electrolyte interface (SEI). Herein, a highly stable Na metal deposition was achieved on the C-SnO2modified Cu current collector. Unlike conventional approaches that rely on binders, our binder-free C-SnO2 modification provides enhanced electron/ion transport, as well as superior electrochemical performance. The CSnO2 layer significantly reduced the nucleation overpotential of Na. First-principles calculations and simulations revealed that C-SnO2 increased the Na+ adsorption energy and homogenized the electric field gradient, leading to a uniform deposition morphology. Furthermore, XRD and XPS depth profiling demonstrated C-SnO2 promoted polycrystalline Na growth and an inorganic-rich SEI formation, which were crucial for long-term stability. Benefiting from this, Na anodes showed exceptional cyclability, achieving up to 3300 cycles (99.8 % CE) in halfcells (1.0 mA cm- 2), 4200 h stability in symmetric cells (1.0 mA cm- 2), and over 820 cycles in full cells (1C). Notably, the C-SnO2 layer can be extended to facilitate stable Li/K metal deposition and may even be utilized for anode-free Na-metal batteries, underscoring its versatility for advanced battery applications.

Amorphous chalcogenide compounds have been extensively studied and widely utilized in advanced electronic and optical devices. In contrast to the significant attention devoted to these compounds, this work focuses on the structure and electronic properties of amorphous phases of elemental S, Se, and Te, investigated through ab initio molecular dynamics simulations. The results reveal that the local structures in amorphous S and Se predominantly consist of 2-coordinated configurations, leading to the formation of long chains. In contrast, amorphous Te exhibits defective octahedral configurations, resulting in interconnected network structures. As the electronegativity increases from Te to S, the void structures become significantly more pronounced, while the number of lone pair electrons shows a slight increase. Concurrently, the dynamic properties and bonding stabilities are markedly enhanced, which determine the stability of the glass. Moreover, the mobility gaps exhibit a notable enlargement with the increasing electronegativity. The localized mid-gap states, which facilitate electron migration, are observed in amorphous S, Se, and Te. However, these states are positioned near the valence bands in amorphous S and Se, whereas they reside deep within the mobility gap in amorphous Te. With the increase of electronegativity, the wide mobility gap and shallow localized state will make the electron migration become difficult in glass. This study offers profound insights into the nature of chalcogen glasses, paving the way for their strategic design and application in electronic and optoelectronic devices.

This paper systematically studies the electronic properties, Raman spectra, and thermal conductivity of MAB phase materials TiAlB, VAlB, and CrAlB using first-principles calculation methods with the VASP software package. The results show that TiAlB, VAlB, and CrAlB all belong to the orthorhombic Cmcm space group and have a layered structure. The electronic states near the Fermi level of TiAlB, VAlB, and CrAlB mainly originate from the 3d orbitals of transition metals and the p orbitals of B, exhibiting metallic conductivity. The phonon spectra of the three materials have no imaginary frequencies, and the optical branches are dominated by the high-frequency vibrations of light-mass B atoms. There are 18 vibrational modes at the center of the Brillouin zone for the three materials, including 6 infrared-active modes (B1u, B2u, B3u) and 9 Raman-active modes (Ag, B1g, B3g). In terms of thermal conductivity, CrAlB exhibits a markedly higher lattice thermal conductivity (50.6 W/(m·K)) than TiAlB (8.6 W/(m·K)) and VAlB (5.8 W/(m·K)). This superiority stems from its smaller Grüneisen parameter, which signals weaker anharmonicity and fewer phonon-scattering channels, whereas the stronger anharmonicity in TiAlB and VAlB suppresses heat transport.

The crystal structure, band characteristics, vibration modes, Raman spectra, and optical properties of Ti3AlB4, Zr3AlB4, and Hf3AlB4 were studied in this paper. By investigating the crystal structure, it is evident that metal atoms Ti, Zr, Hf, and B atoms form a close-packed framework, while Al atoms occupy the interstitial sites, thereby enhancing structural stability. The band structure analysis indicates that these materials exhibit metallic characteristics. The density of states does not vanish at the Fermi level, and there is a crossover between different energy bands, which influences electronic transport and optical properties. The results of the infrared and Raman spectroscopy calculations indicate that these materials exhibit 24 vibrational modes at the Γ point, comprising 12 infrared-active modes and 9 Raman-active modes. The vibrational frequencies are closely linked to specific chemical bonds and atomic movements. Optical analysis reveals strong absorption across the infrared, visible, and ultraviolet spectra, accompanied by pronounced reflection over a specific wavelength range. Consequently, they have the potential to be utilized as coatings for spacecraft.