As a potential electrode material for sodium-ion batteries (SIBs), Mo2C-based MXene possesses exceptional electrical conductivity, a large specific surface area, and facilitates rapid Na+ diffusion. However, the preparation process inevitably introduces functional groups on the material's surface, which significantly influence its electrochemical performance. The influence of co-doping S and O functional groups on the electrochemical performance of Molybdenum carbide (Mo2C) materials was investigated using first-principles calculations, four stable symmetric configurations-Mo2CO2, Mo2CO4/3S2/3, Mo2CO2/3S4/3 and Mo2CS2 with excellent electronic conductivity and thermodynamic stability, were selected to systematically evaluate their electrochemical properties. The results indicate that the Na+ diffusion barriers follow the order: Mo2CS2 (0.06 eV) < Mo2CO2 (0.15 eV) < Mo2CO4/3S2/3 (0.17 eV) < Mo2CO2/3S4/3 (0.25 eV). Regarding Na+ storage capacity, the maximum Na+ adsorption concentrations correspond to theoretical capacities of 380 mAhg(-1), 400 mAhg(-1), 403 mAhg(-1), and 487 mAhg(-1) for Mo2CO2, Mo2CS2, Mo2CO4/3S2/3, and Mo2CO2/3S4/3, respectively. Remarkably, Mo2CO2/3S4/3 exhibits an outstanding storage capacity with a low average voltage of 0.59 V, surpassing those of many previously reported anode materials. This work elucidates the regulatory role of functional groups in tuning MXene properties and offers a novel strategy for designing high-performance MXene-based anodes for SIBs.

All-dielectric metasurfaces based on bound states in the continuum (BIC) have become a research hotspot in sensing applications, yet achieving a high quality factor (Q-factor) while maintaining high sensitivity remains a significant challenge. This paper proposes an all-dielectric metasurface sensor based on a dual-gap square split-ring resonator (SRR). By introducing identical triangular perturbations-adding to the upper half-ring and removing from the lower half-ring-the inplane C2v symmetry is strategically broken, effectively converting a symmetry-protected BIC (SP-BIC) into an observable quasi-BIC with a high Q-factor. This structure excites dual Fano resonances in the near-infrared region, dominated by electric quadrupole and magnetic dipole modes, respectively. The electric quadrupole mode achieves a refractive index sensitivity of up to 500 nm/RIU in an aqueous environment, along with a Q-factor of 1.3 & times; 104, resulting in an outstanding figure of merit (FOM) of 4370. This work overcomes the conventional trade-off between high Q-factor and high sensitivity, offering an effective design strategy and theoretical foundation for developing high-performance integrated optical sensors.

Rechargeable zinc-air batteries (ZABs) represent a viable solution to energy challenges; however, the slow kinetics of the oxygen reduction reaction (ORR) seriously hinder their commercial application. Metal-organic frameworks (MOFs) have emerged as promising ORR catalysts due to their high activity, stability and low cost. In this work, a metal-organic framework catalyst, high-entropy zeolitic imidazolate frameworks (HEZIFs), rich in M-N-C bonds, was successfully synthesized through the pyrolysis of a nanoscale alloy ZIF precursor. This precursor was obtained via a solvothermal coprecipitation method, utilizing Zn to create defects and employing Mn, Fe, Co, Ni and Cu as the stable structural elements. The structure derived from the high-entropy ZIF (HEZIF) precursor is not only conducive to the formation of N-doped carbon matrix with high specific surface area and rich multi-level pores, but also synergistically optimizing the electron transfer path and exposing more active sites. The synergistic effect and cocktail effect stemming from the various metal ions provide more efficient reaction sites for the ORR. Electrochemical performance assessments indicate that the HEZIF exhibits commendable oxygen reduction catalytic activity (with positive half-wave potential of 0.84 V) and stability. Furthermore, the assembled zinc-air battery demonstrates excellent device performance, including a high power density of 136.0 mW cm-2, a specific capacity of 808.96 mAh g-Zn 1 and excellent stability of 160 h, surpassing the commercial benchmark Pt/C-based ZAB.

Biomass-derived hard carbon (HC) materials, with their abundant resources and low cost, are considered highly promising anode candidates for sodium-ion batteries (SIBs). However, their practical application is hindered by limitations such as low electrical conductivity and narrow interlayer spacing, which collectively restrict sodiumion (Na+) storage and transport. In this work, an in-situ strategy involving concurrent incorporation of nickel (Ni) nanoparticles and phosphorus (P) doping (denoted as D-HC) was developed to improve the electrochemical performance of bamboo-derived HC anodes in SIBs. Both density functional theory (DFT) calculations and experimental results reveal that P-doping effectively enlarges the interlayer spacing (from 0.368 nm to 0.393 nm) and increases active sites, thereby enhancing capacity; meanwhile, Ni improves electrical conductivity and accelerates Na+ diffusion. The synergistic effect of Ni nanoparticle incorporation and P-doping not only increases the number and size of closed pores in bamboo-derived HC-thus boosting specific capacity in the low-voltage region, but also promotes electrons and Na+ transport, leading to improved rate capability. The resulting DHC-based anode exhibits outstanding Na+ storage performance, delivering a high reversible capacity of 322.01 mAh g- 1 at 0.05 A g- 1 with an initial Coulombic efficiency (ICE) of 86.4%, excellent long time cycle life (3000 cycles at 2 A g- 1), and good low-temperature properties (full cell operating at -25 degrees C for 1000 cycles), significantly outperforming the prime HC. This study confirms that the combined strategy of Ni nanoparticle incorporation and P doping is effective in enhancing the Na+ storage performance of biomass-based electrode materials.

Molybdenum carbide (Mo2C) is regarded as a promising anode material for sodium ion batteries (SIBs) due to its favorable thermodynamic and kinetic stability. Nevertheless, its practical application is hindered by sluggish reaction kinetics during Na+ intercalation and significant volume expansion. Previous researches indicate that innovative structural design can effectively address these challenges. In this work, a sea urchin-like Mo2C/C composite is successfully synthesized through precise control of air exposure during the reaction process. This unique biomimetic architecture offers multiple advantages for Na+storage: the stable spine-like framework affords a high specific surface area and abundant active sites while shortening ion diffusion pathways; meanwhile, the hollow carbon shell enhances electrical conductivity and accommodates volume variations. Density functional theory (DFT) calculations confirm improved conductivity of the composite, along with reduced adsorption energy and diffusion barriers for Na+ ions. The resulting Mo2C/C-SA anode exhibits outstanding electrochemical performance, delivering a reversible capacity of 402.8 mAh g-1 at 0.1 A g-1, and demonstrating remarkable long-term cycling stability with a retention of 142.1 mAh g-1 after 1200 cycles at 5 A g-1. When assembled in a full cell, the anode enables an energy density of 196.03 Wh kg-1. This study provides a new design strategy for developing high-performance Mo2C-based anode materials for SIBs.

The terahertz metamaterials and metasurfaces with strong optical chirality are vital in a wide range of applications, such as chirality detection, bimolecular sensing and terahertz communication. Here, we proposed a metal spiral metasurface (MSM) that can achieve strong circular dichroism with high circular polarization extinction ratio in terahertz region. The designed metasurface can support two kinds of electric resonance modes, which can be used to control the polarization and phase of light at dual frequency bands. The chiroptical responses of structure are enhanced by lowering symmetry of MSM and the thin-film interference effects. The simulation results demonstrate that the left-hand and right-hand circularly polarized light waves can be selectively converted into linearly polarized light waves with transmission efficiency up to 80% at dual frequency bands. The amplitude of the circular dichroism is up to 0.8 and the circular polarization extinction ratio is larger than 90 at each frequency band. Moreover, the sign of CD in each frequency band can be controlled and flipped by simply varying the rotation angle of spiral metasurface. The studied results have potential applications in polarization manipulation, chiral metasurface sensor, and biomedical diagnosis.

Artificial supramolecular materials have found extensive applications in many fields such as biology, chirality, and information science. The Langmuir-Blodgett (LB) film technology, as an effective means of molecular assembly, offers broad prospects for the preparation of functional materials with specific properties. This study focuses on a chiral and amphiphilic molecule - the glutamine-azobenzene molecule (GAZS) composite LangmuirBlodgett film. Through the LB technique, GAZS molecules were successfully compounded with MB, ST, and RhB subphases to form multi-layer films. The interfacial aggregation behavior of this film was thoroughly explored, and its morphological characteristics and spectral properties were analyzed. The results show that the LB films which are prepared exhibit the same J-aggregation state. The surface-enhanced Raman scattering (SERS) experiment shows that the composite LB films which are prepared have outstanding Raman enhancement performance, with an enhancement factor (EF) of 2.46 x 105. Additionally, the Raman intensity has a relative standard deviation of 12.30 %, which implies that the composite films possess excellent reproducibility and uniformity. Thus, they are suitable for the detection of trace molecules. The circular dichroism spectroscopy proves that the LB films formed after the combination of GAZS molecules and dye subphases exhibit obvious chiral signals, providing some insights into the performance research and application expansion of chiral photosupramolecular material composite LB films. Through the photoelectric conversion test of transferring multilayer films onto indium tin oxide (ITO), it is found that the self-assembled LB films exhibit outstanding photoelectrochemical characteristics. The GAZS molecules show a more powerful photoelectric conversion effect. under the RhB subphase, providing a reference for the further exploration of the applications of GAZS molecule composite LB films in optoelectronic devices.

In recent years, light-controlled layer-by-layer (LbL) self-assembly technology has attracted much attention due to its dynamic modulation capability. By introducing light-responsive molecules, the precise regulation of film thickness, components, and structure has been successfully realized. This study presents the fabrication of lightcontrolled polyacrylic acid/4-aminoazobenzene-polyethyleneimine-silver nanoparticle (PAA/4-AAB-PEI-AgNPs) composite films through LbL technique. By exploiting the photoisomerization capability of 4-AAB, we achieved precise microstructural control of the films under ultraviolet (UV) irradiation. Comprehensive characterization revealed that UV irradiation triggered a trans-to-cis conformational transition in 4-AAB molecules. This transition directed the assembly into a well-defined, long-range ordered biomimetic network structure that closely mimics the morphology of a biological neuronal network. Surface-enhanced Raman scattering (SERS) measurements revealed significant performance enhancements, with the enhancement factor (EF) increasing from 3.72 x 105 to 8.59 x 105 following UV treatment. Concurrently, the relative standard deviation (RSD) of SERS signals decreased from 25.17 % to 11.09 %. This study developed a high-performance SERS substrate based on light-controlled molecular conformational conversion, which provides a new idea for the development of smart sensing materials and environmental monitoring technologies.

Cholesterol derivatives play a vital role in various fields, including medicine, biology, and smart materials. The Langmuir-Blodgett (LB) technology uses molecular self-assembly to create interfacially organized thin film materials with unique characteristics. This work primarily used two cholesterol derivatives (CCA and CCH) coupled with various dyes to create multilayer composite LB films. The SERS test determined the enhancement factor EF= 1.07 x 105 for the CCA/ST composite film and EF= 1.12 x 105 for the CCH/ST multilayer composite films, with relative standard deviation RSD= 12.58 % and 3.86 %, respectively. The result demonstrates the superior signal responsiveness and uniformity of the resultant LB films, offering a novel option for active substrate materials in SERS detection of trace compounds. The photoelectric response signal of the CCA/dye and CCH/dye composite LB films was demonstrated to be sensitive by the photoelectric conversion test, and the films' superior reusability was demonstrated by the persistence of the same pattern over several recurring cycles. It offers a novel idea for investigating the use of cholesterol derivatives in optoelectronic devices in more detail.

Harnessing solar energy through the strategic design of metamaterials is essential for advancing sustainable energy technologies. The development of such materials is crucial for enhancing the efficiency of solar energy conversion, vital for photothermal and photovoltaic systems, and water purification through desalination processes. In this study, we present a novel ultra-thin metamaterial-based solar selective absorber. It integrates a tungsten ground substrate, a thin dielectric film, square arrays of tungsten rings and cylindrical disks filled with dielectric material, and a topmost dielectric film. This nanostructured design achieves an exceptional solar absorption efficiency of 95.04%, while maintaining an incredibly low thermal emittance of just 3.6% at temperatures of 100 degrees C. Moreover, this innovative structure achieves an impressive photothermal conversion efficiency of 92.7% under standard solar irradiation. The near-perfect absorption in the visible to near-infrared spectrum (400-1600 nm) is facilitated by a synergistic combination of impedance matching, the intrinsic absorption characteristics of tungsten, and the excitation of magnetic and electric resonances, including localized and propagating surface plasmon resonances. These mechanisms are comprehensively discussed within. The absorber also exhibits excellent polarization insensitivity and maintains high efficiency across a broad spectrum of incident angles, highlighting its promising potential for various solar thermal applications.

Antimony (Sb)-based anodes for sodium-ion batteries (SIBs) face critical challenges in reconciling high theoretical capacity (similar to 660 mAh g-1) with structural degradation caused by severe volume expansion (similar to 400%) during cycling. Herein, a spider web-inspired Sb2MoO6@C@CNF composite is synthesized through an integrated hydrothermal-electrospinning strategy, featuring a dual-carbon architecture where polyacrylonitrile (PAN)-derived carbon nanofibers (CNFs) interweave with polypyrrole (PPY)-carbonized N-doped conductive networks. This hierarchical design synergistically enhances electron transport kinetics and accommodates mechanical stress, as evidenced by the anode delivering a reversible capacity of 210 mAh g-1 after 5000 cycles at 5 & Aring; g-1 (96.3% capacity retention). The dual-carbon confinement mechanism effectively restricts Sb2MoO6 nanoparticle pulverization while maintaining robust electrode integrity, offering a universal strategy for alloy-type anode stabilization.

Transition metal selenides (TMS) are promising anode materials for sodium-ion batteries (SIBs), yet their practical implementation is hindered by intrinsic limitations including sluggish ion diffusion kinetics and severe structural degradation during repetitive sodiation/desodiation processes. To overcome these challenges, we present a biomimetic design strategy through the in situ implantation of cobalt precursor seeds within nitrogendoped carbon nanofibers (N-CNFs), subsequently evolving into a unique spore-like CoSe2@N-CNFs architecture. This bioinspired configuration achieves synergistic multifunctionality through: (1) Hierarchical porosity optimization that enhances electrolyte accessibility while facilitating rapid ion transport pathways; (2) Reinforced interfacial integration that minimizes charge transfer resistance; (3) Structural confinement effects that mitigate electrode pulverization. The engineered anode demonstrates unprecedented electrochemical durability, sustaining 30,000 cycles at 10 A g- 1 with an ultralow capacity decay of 0.0012 % per cycle. Mechanistic investigations through ex situ spectroscopic analysis confirm a highly reversible conversion-type sodium storage mechanism. Practical viability is further validated in full-cell configurations paired with Na3V2(PO4)3@C cathodes, delivering a capacity retention of 101.15 mAh g- 1 after 300 cycles at 0.5 A g- 1. This work not only proposes a generalizable strategy for fabricating mechanically robust metal selenide-carbon hybrids but also provides fundamental insights into designing high-performance SIB anodes for fast-charging applications.

To encapsulate metal sulfides/selenides into carbon substrates is effective to enhance the cycling stability and rate capability of sodium-ion batteries (SIBs). In this paper, ZnSe nanoparticles rooted in N-doped carbon nanofibers (ZnSe@CNFs) were prepared by typical electrospinning technique coupled with carbonization and selenylation. As a result, ZnSe nanoparticles were wrapped by multichannel carbon fibers, which is conducive to the fast transport of sodium-ions and electrons and ensure the structural integrity. Benefiting from the special structure and the synergistic effect of two constituent, ZnSe@CNFs anode exhibits superior cycling stability of 2000 cycles at 1 A/g, with a capacity retention rate of 97.4%, equivalent to 0.0132 parts per thousand of attenuation per cycle. The carbon-encapsulation method involved in this paper has great application potential in the preparation of electrode materials.

This paper proposes a novel nano-sensor structure consisting of the metal-insulator-metal (MIM) waveguide with two rectangular baffles and a semicircular ring rectangular resonator (SRRR). The sensor's transmission characteristics are investigated using the finite-difference time-domain (FDTD) method. The results show that the transmission spectrum of the sensor exhibits the Fano resonance shape. The influences of refractive index and structural parameters on transmission characteristics are systematically investigated. The maximum sensitivity (S) of the sensor can get up to 2560 nm/RIU (refractive index unit), and the figure of merit (FOM) is 1080. In addition, the potential application of the structure in temperature sensing is explored with a sensitivity of 0.87 nm/degrees C. The proposed structure has promising applications in nanoscale optical sensing.

In this study, the subwavelength grating multilayer structure with asymmetric boundary conditions is investigated using scattering matrix theory. A formal expression linking the reflection phase to the dielectric constant of the grating boundary medium is derived. Based on this expression, simulation experiments are conducted using the timedomain finite difference method to validate the pre designed silicon-based liquid crystal structure embedded with subwavelength gold gratings(G-LCoS). Through continuous optimization of the asymmetric boundary conditions of the subwavelength gold gratings, nearly 2p phase modulation across multiple wavelengths in the visible spectrum is realized via the G-LCoS. The formal expression and optimization process detailed in this paper offer reference for the design of devices with dynamic asymmetric boundary conditions, particularly complex amplitude modulation devices featuring nano/ micro-scale structures. Additionally, this study contributes to a deeper understanding of these devices in terms of their physical mechanisms to a certain extent.

Layered MoS2 are promising anode materials due to the applicable interlayer spacing (0.62 nm) and high theoretical specific capacity (669mAh g-1). Nevertheless, the low electric conductivity, large structure variation and sluggish ionic kinetics result in rapid capacity decay and suboptimal cycle performance of MoS2-based sodium-ion batteries (SIBs). Here, the two-step methodology was used to grow MoS2 sheets on the surface of Ndoped carbon fibers with CoS2 nanoparticles encapsulated in. The obtained MoS2@CoS2@CNFs exhibit a distinctive hierarchical structure, which increases the electrode-electrolyte interface, thereby minimizing the diffusion distance of Na+. Experiment and calculation results demonstrates that the incorporation of CoS2 not only enhances the ion mobility and pseudocapacitance contribution of the electrode material, but also amplifies its conductivity and adsorption energy of Na+, ultimately elevating the rate performance and ensuring long cycle stability of SIBs. Consequently, the MoS2@CoS2@CNFs composite enabled a commendable capacity of 494.5 mAh g-1 after 700 cycles at 0.5 A g-1. Impressively, when the current density was increased to 2 A g-1, it reserved a capacity of 310 mAh g-1 for 2000 cycles. To encapsulation of CoS2 nanoparticles in the MoS2@CoS2@CNFs composite promotes the stability of the anodes and boosts durable Na+ storage, making it a promising method for designing high performance SIBs.

In this work, we introduce a stacked pair of graphene ribbons array into a slab waveguide to achieve tunable optical absorption of a structure in the mid-infrared region. The quasi-bound states in the continuum (quasi-BICs) based on the selective guided resonances can be realized by alternatively changing the Fermi energy of graphene ribbons. Moreover, the radiation coupling rate of quasi-BIC can be modulated by changing the Fermi energy of graphene, which contributes to tunable optical absorption of the structure. Different from the effect of plasmon resonance of graphene ribbons, the resonance frequency of the quasi-BIC is insensitive to the Fermi energy of graphene. The absorption modulation depth can be larger than 80%. The studied results may have potential applications in switchable infrared photodetectors and thermal radiation systems.

In this work, we numerically study the tunable light absorption of monolayer graphene at the near-infrared region by the guided mode resonance in a compound grating-coupled waveguide structure. A biased graphene capacitor is placed below the coupled waveguides. The electromagnetically induced transparency phenomenon is demonstrated by the resonant coupling of guided modes. The light absorption of monolayer graphene at the transparency window can be dynamically tuned by shifting the Fermi energy of graphene in capacitor. The absorption modulation depth of monolayer graphene at the transparency window can vary quickly from zero to nearly 100 % around the interband transition of graphene in capacitor. These results have potential applications in the active photodetectors and photoconductive devices.

Metal sulfides based on a conversion mechanism possess high theoretical specific capacity, making them suitable for high-energy-density sodium-ion batteries (SIBs). However, they suffer from rapid capacity decay when assembled into full batteries due to dynamic hysteresis and large volume expansion. In this paper, the architectural engineering approach to construct MoS2/Fe2O3 @ carbon fiber heterostructures is proposed to overcome the above issues. The heterojunction formed by MoS2 and Fe2O3 would promote ion/electron transfer, while the carbon nano-fibers serve as a holder to maintain structural stability and ensure the rapid transport of electrons. The full battery in which the as-prepared MoS2/Fe2O3 @ carbon fiber anode is paired with a Na3V2(PO4)3/C cathode delivers a reversible capacity of 61.1 mAh g-1 at 500 mA g-1 for 1600 cycles without attenuation. Experimental characterization and theoretical calculation results show that this structural engineering approach improves the ion diffusion efficiency, enhances the conductivity, provides a more appropriate sodium ion adsorption energy, and thus extends the cycling life of the SIB. This work demonstrates the efficiency of architectural engineering and paves the way to design ultra-long-cycling Na-ion batteries.