We present a compact optical delay line(ODL)with wide-range continuous tunability on thin-film lithium niobate platform.The proposed device integrates an unbalanced Mach-Zehnder interferometer(MZI)architecture with du...We present a compact optical delay line(ODL)with wide-range continuous tunability on thin-film lithium niobate platform.The proposed device integrates an unbalanced Mach-Zehnder interferometer(MZI)architecture with dual tunable couplers,where each coupler comprises two 2×2 multimode interferometers and a MZI phase-tuning section.Experimental results demonstrate continuous delay tuning from 0 to 293 ps through synchronized control of coupling coefficients,corresponding to a 4 cm path difference between interferometer arms.The measured delay range exhibits excellent agreement with theoretical predictions derived from ODL waveguide parameters.This result addresses critical challenges in integrated photonic systems that require precise temporal control,particularly for applications in optical communications and quantum information processing,where a wide tuning range is paramount.展开更多
Controllably tuning the sensing performance of flexible mechanical sensors is important for them to realize on-demand sensing of various mechanical stimuli in different application scenarios.However,current regulating...Controllably tuning the sensing performance of flexible mechanical sensors is important for them to realize on-demand sensing of various mechanical stimuli in different application scenarios.However,current regulating strategies focus on the construction process of individual sensors,the response performance of the as-formed sensors is still hard to autonomously tune with external stimulus changes like human skin.Here,we propose a new strategy that realizes post-tuning of the sensing performance by introducing a temperature-dependent phase transition elastomer into the sensing film.Through an interfacially confined photopolymerization reaction,a graphene-based phase-transition elastomeric(GPTE)film with a robust interface and excellent conductivity is well-formed at the water/air interface.Benefiting from the crystallization-melt dynamic switching in the elastomer network,the GPTE film could experience the reversible transformation between soft(1.65 MPa)and stiff(12.27MPa)states,showing huge changes of elastic modulus up to seven times near the phase transition temperature(28.5℃).Furthermore,the GPTE film is designed into a suspended perceptual configuration realizing the dynamic detection of 3D deformation adapted to temperature changes with up to 3.5-fold difference in response sensitivity.Finally,the self-adaptive sensing behavior of temperature-mediated 3D deformation is demonstrated by the effective detection of the dynamic stimulation process of cold and hot water droplets by the GPTE suspended film.The proposed strategy of phase transition-induced post-tuning of sensing performance could greatly facilitate flexible mechanical sensors towards a more intelligent one.展开更多
Multiple functional metasurfaces with high information capacity have attracted considerable attention from researchers.This study proposes a 2-bit tunable spin-decoupled coded metasurface designed for the terahertz ba...Multiple functional metasurfaces with high information capacity have attracted considerable attention from researchers.This study proposes a 2-bit tunable spin-decoupled coded metasurface designed for the terahertz band,which utilizes the tunable properties of Dirac semimetals(DSM)to create a novel multilayer structure.By incorporating both geometric and propagating phases into the metasurface design,we can effectively control the electromagnetic wave.When the Fermi level(EF)of the DSM is set at 6 meV,the electromagnetic wave is manipulated by the gold patch embedded in the DSM film,operating at a frequency of 1.3 THz.When the EF of the DSM is set at 80 meV,the electromagnetic wave is manipulated by the DSM patch,operating at a frequency of 1.4 THz.Both modes enable independent control of beam splitting under left-rotating circularly polarized(LCP)and rightrotating circularly polarized(RCP)wave excitation,resulting in the generation of vortex beams with distinct orbital angular momentum(OAM)modes.The findings of this study hold significant potential for enhancing information capacity and polarization multiplexing techniques in wireless communications.展开更多
The excellent mechanical properties make graphene promising for realizing nanomechanical resonators with high resonant frequencies,large quality factors,strong nonlinearities,and the capability to efectively interface...The excellent mechanical properties make graphene promising for realizing nanomechanical resonators with high resonant frequencies,large quality factors,strong nonlinearities,and the capability to efectively interface with various physical systems.Equipped with gate electrodes,it has been demonstrated that these exceptional device properties can be electrically manipulated,leading to a variety of nanomechanical/acoustic applications.Here,we review the recent progress of graphene nanomechanical resonators with a focus on their electrical tunability.First,we provide an overview of diferent graphene nanomechanical resonators,including their device structures,fabrication methods,and measurement setups.Then,the key mechanical properties of these devices,for example,resonant frequencies,nonlinearities,dissipations,and mode coupling mechanisms,are discussed,with their behaviors upon electrical gating being highlighted.After that,various potential classical/quantum applications based on these graphene nanomechanical resonators are reviewed.Finally,we briefy discuss challenges and opportunities in this feld to ofer future prospects for the ongoing studies on graphene nanomechanical resonators.展开更多
Soft actuators are inherently flexible and compliant,traits that enhance their adaptability to diverse environments and tasks.However,their low structural stiffness can lead to unpredictable and uncontrollable complex...Soft actuators are inherently flexible and compliant,traits that enhance their adaptability to diverse environments and tasks.However,their low structural stiffness can lead to unpredictable and uncontrollable complex deformations when substantial force is required,compromising their load-bearing capacity.This work proposes a novel method that uses gecko setae-inspired adhesives as interlayer films to construct a layer jamming structure to adjust the stiffness of soft actuators.The mechanical behavior of a single tilted microcylinder was analyzed using the energy method to determine the adhesion force of the adhesives.The gecko-inspired adhesive was designed under the guidance of the adhesion force model.Testing under various loads and directions revealed that the tilted characteristic of microcylinders can enhance the adhesion force in its grasping direction.The adhesive demonstrated excellent adhesion performance compared to other typical adhesives.A tunable stiffness actuator using gecko setae-inspired adhesives(TSAGA),was developed with these adhesives serving as interlayer films.The stiffness model of TSAGA was derived by analyzing its axial compression force.The results of stiffness test indicate that the adhesives serve as interlayer films can adjust the stiffness in response to applied load.TSAGA was compared with other typical soft actuators in order to evaluate the stiffness performance,and the results indicate that TSAGA exhibits the highest stiffness and the widest tunable stiffness range.This demonstrates the superior performance of the setae-inspired adhesives as interlayer films in terms of stiffness adjustment.展开更多
Metamaterials with multistability have attracted much attention due to their extraordinary physical properties. In this paper, we report a novel multistable strategy that is reversible under external forces, based on ...Metamaterials with multistability have attracted much attention due to their extraordinary physical properties. In this paper, we report a novel multistable strategy that is reversible under external forces, based on the fact that a variational reversible locally resonant elastic metamaterial(LREM) with four configurations is proposed. Through a combination of theoretical analysis and numerical simulations, this newly designed metamaterial is proven to exhibit different bandgap ranges and vibration attenuation properties in each configuration. Especially, there is tunable anisotropy shown in these configurations, which enables the bandgaps in two directions to be separated or overlapped. A model with a bandgap shifting ratio(BSR) of 100% and an overlap ratio of 25% is set to validate the multistable strategy feasibility. The proposed design strategy demonstrates significant potentials for applications in versatile scenarios.展开更多
In this paper,a tunable metamaterial absorber based on a Dirac semimetal is proposed.It consists of three different structures,from top to bottom,namely a double semicircular Dirac semimetal resonator,a silicon dioxid...In this paper,a tunable metamaterial absorber based on a Dirac semimetal is proposed.It consists of three different structures,from top to bottom,namely a double semicircular Dirac semimetal resonator,a silicon dioxide substrate and a continuous vanadium dioxide(VO_(2))reflector layer.When the Fermi energy level of the Dirac semimetal is 10 meV,the absorber absorbs more than 90%in the 39.06-84.76 THz range.Firstly,taking advantage of the tunability of the conductivity of the Dirac semimetal,dynamic tuning of the absorption frequency can be achieved by changing the Fermi energy level of the Dirac semimetal without the need to optimise the geometry and remanufacture the structure.Secondly,the structure has been improved by the addition of the phase change material VO_(2),resulting in a much higher absorption performance of the absorber.Since VO_(2)is a temperature-sensitive metal oxide with an insulating phase below the phase transition temperature(about 68℃)and a metallic phase above the phase transition temperature,this paper also analyses the effect of VO_(2)on the absorptive performance at different temperatures,with the aim of further improving absorber performance.展开更多
In two-dimensional bilayer systems,twist-angle-dependent electronic and thermoelectric properties have garnered significant scientific interest in recent years.In this work,based on a combination of density functional...In two-dimensional bilayer systems,twist-angle-dependent electronic and thermoelectric properties have garnered significant scientific interest in recent years.In this work,based on a combination of density functional theory and nonequilibrium Green’s function method,we explore the electronic and thermoelectric properties in blue-phosphorene nanoribbon-based heterojunction(BPNRHJ)with and without blue-phosphorene nanoribbon(BPNR)stack.Our calculations find that the electronic conductance and power factor can be strongly enhanced by the BPNR stack,and their enhancements can be further observed with the twist between the layers.The main reason for this is the electronic hybridization between the layers can provide new transport channels,and the twist can modulate the strength of interlayer electronic hybridization,resulting in extremely violent fluctuations in electron transmission and hence an enhanced power factor.While the phonon thermal conductance exhibits very low dependence on the layer stack and twist.Combining these factors,our results reveal that the thermoelectric performance can be greatly modulated and enhanced in twist bilayer BPNRHJ:the figure of merit will be over 2.5 in 4-4-ZBPNR@ZGNR-AA-8.8∘at 500 K.展开更多
Lead-free double perovskites have gained recognition as top luminescent materials due to their environmental friendliness,high chemical stability,structural adjustability,and excellent photoelectric properties.However...Lead-free double perovskites have gained recognition as top luminescent materials due to their environmental friendliness,high chemical stability,structural adjustability,and excellent photoelectric properties.However,the poor modulation of emission restricts their applications,and it is highly desirable to explore stable and efficient double perovskites with multimode luminescence and adjustable spectra for multifunctional photoelectric applications.Herein,the rare earth ions Ln^(3+)(Er^(3+)and Ho^(3+))-doped Cs_(2)NaYCl_(6):Sb^(3+)crystals were synthesized by a simple solvothermal route.The X-ray diffraction pattern(XRD),energy-dispersive spectroscopy(EDS),X-ray photoelectron spectroscopy(XPS),and elemental mapping images demonstrate that the Sb^(3+),Er^(3+),and Ho^(3+)ions have been homogeneously incorporated into the Cs_(2)NaYCl_(6)crystals.As anticipated,the emissio n spectra of Cs_(2)NaYCl_(6):Sb^(3+)/Ln^(3+)are composed of two bands.One broad blue band derives from self-trapped exciton(STE)in[SbCl_(6)]3-octahedra while another group of emission peaks stems from the f-f transitions of Ln^(3+)ions.The emission colors of Cs_(2)NaYCl_(6):Sb^(3+)/Ln^(3+)phosphors can be tuned in a wide range by modulating the doping concentrations of Ln^(3+)ions.The efficient energy transfer from STE to Ln^(3+)is the key point to achieving the efficient and tunable emissions Cs_(2)NaYCl_(6):Sb^(3+)/Ln^(3+)samples.Interestingly,Cs_(2)NaYCl_(6):Sb^(3+)/Ln^(3+)can also exhibit characteristic up-conversion luminescence of Ln^(3+)under nearinfrared(NIR)excitation besides the down-conversion luminescence,revealing that the materials may have potential applicability in multimode anti-counterfeiting and information encryption applications.Furthermore,the light emitting diodes(LEDs)assembled by Cs_(2)NaYCl_(6):Sb^(3+)and Cs_(2)NaYCl_(6):Sb^(3+)/Ln^(3+)phosphors display dazzling blue,green,and red emissions under a forward bias current,which indicates that the as-obtained double perovskites materials may have great potential in solid-state lighting and optoelectronic devices.展开更多
Despite significant progress has been achieved regarding the shuttle-effect of lithium polysulfides,the suppressed specific capacity and retarded redox kinetics under high sulfur loading still threat the actual energy...Despite significant progress has been achieved regarding the shuttle-effect of lithium polysulfides,the suppressed specific capacity and retarded redox kinetics under high sulfur loading still threat the actual energy density and power density of lithium-sulfur batteries.In this study,a graham condenser-inspired carbon@WS_(2)host with coil-in-tube structure was designed and synthesized using anodic aluminum oxide(AAO)membrane with vertically aligned nanopores as template.The vertical array of carbon nanotubes with internal carbon coils not only leads to efficient charge transfer across through the thickness of the cathode,but also provides significant confinement to polysulfide diffusion towards both the lateral and longitudinal directions.Few-layer WS_(2)in the carbon coils perform a synergistic role in suppressing the shuttle-effect as well as boosting the cathodic kinetics.As a result,high specific capacity(1180 m Ah/g at 0.1 C)and long-cycling stability at 0.5 C for 500 cycles has been achieved at 3 mgS/cm^(2).Impressive areal capacity of 7.4 m Ah/cm^(2)has been demonstrated when the sulfur loading reaches 8.4 mg/cm^(2).The unique coil-in-tube structure developed in this work provides a new solution for high sulfur loading cathode towards practical lithium-sulfur batteries.展开更多
Control crosslink network and chain connectivity are essential to develop shape memory polymers(SMPs)with high shape memory capabilities,adjustable response temperature,and satisfying mechanistical properties.In this ...Control crosslink network and chain connectivity are essential to develop shape memory polymers(SMPs)with high shape memory capabilities,adjustable response temperature,and satisfying mechanistical properties.In this study,novel poly(ε-caprolactone)(PCL)-poly(2-vinyl)ethylene glycol(PVEG)copolymers bearing multi-pendant vinyl groups is synthesized by branched-selective allylic etherification polymerization of vinylethylene carbonate(VEC)with linear and tetra-arm PCLs under a synergistic catalysis of palladium complex and boron reagent.Facile thiol-ene photo-click reaction of PCL-PVEG copolymers with multifunctional thiols can rapidly access a serious crosslinked SMPs with high shape memory performance.The thermal properties,mechanical properties and response temperature of the obtained SMPs are tunable by the variation of PCL prepolymers,vinyl contents and functionality of thiols.Moreover,high elastic modulus in the rubbery plateau region can be maintained effectively owing to high-density topological networks of the PCL materials.In addition,the utility of the present SMPs is further demonstrated by the post-functionalization via thiol-ene photo-click chemistry.展开更多
Layer pseudospins,exhibiting quantum coherence and precise multistate controllability,present significant potential for the advancement of future computing technologies.In this work,we propose an in-memory probabilist...Layer pseudospins,exhibiting quantum coherence and precise multistate controllability,present significant potential for the advancement of future computing technologies.In this work,we propose an in-memory probabilistic computing scheme based on the electrical manipulation of layer pseudospins in layered materials,by exploiting the interaction between real spins and layer pseudospins.展开更多
We propose a novel approach to generate and manipulate topological Floquet bound states in the continuum(BICs)via a class of systems constructed by coupling two identical periodically driven one-dimensional Su-Schrief...We propose a novel approach to generate and manipulate topological Floquet bound states in the continuum(BICs)via a class of systems constructed by coupling two identical periodically driven one-dimensional Su-Schrieffer-Heeger chains.The formation of topological Floquet BICs can be adjusted only by tuning the driving amplitude or frequency,regardless of whether the static system has BICs or not.The interchain bias can only change the localization property of topological Floquet BICs,and a bigger bias can lead to transforming topological Floquet BICs into bound states out of the continuum(BOCs).But it does not change the topological properties of these topological Floquet states.Based on the repulsion effect of edge states,we propose to detect occurrence of topological Floquet BICs and transition point between topological Floquet BICs and BOCs using quantum walk.Our work provided a convenient and realistic approach for the experimental realization and manipulation of BICs in a single-particle quantum system.展开更多
Terahertz(THz)switches are essential components of THz communication systems.THz switches based on conventional waveguides and photonic crystal structures are sensitive to manufacturing defects and sharp bending,resul...Terahertz(THz)switches are essential components of THz communication systems.THz switches based on conventional waveguides and photonic crystal structures are sensitive to manufacturing defects and sharp bending,resulting in high scattering losses.In addition,THz switches with tunable working bandwidths have not yet been demonstrated.Here,we design THz switches based on a topological valley photonic crystal(VPC)structure using magnetic materials,which can achieve high forward transmittance based on the unique spin–valley locking effect.The broad working bandwidth allows selective turning on and off at a designed wavelength region by controlling the applied magnetic field.The designed THz switch can achieve an extinction ratio of up to 31.66 dB with an insertion loss of less than 0.13 dB.The 3-dB bandwidth is up to 49 GHz.This tunable THz switch can be experimentally fabricated by current fabrication techniques and thus can find broad applications in THz communication systems.展开更多
Perovskite semiconductors show great promise as gain media for all-solution-processed single-mode microlasers.However,despite the recent efforts to improve their lasing performance,achieving tunable single-mode microl...Perovskite semiconductors show great promise as gain media for all-solution-processed single-mode microlasers.However,despite the recent efforts to improve their lasing performance,achieving tunable single-mode microlasers remains challenging.In this work,we address this challenge by demonstrating a tunable vertical cavity surface emitting laser(VCSEL)employing a tunable gain medium of halide phase-change perovskites-specifically MAPbI_(3) perovskite,sandwiched between two highly reflective mirrors composed of bottom-distributed Bragg reflectors(DBRs).This VCSEL possesses single-mode lasing emission with a low threshold of 23.5μJ cm^(−2) under 160 K,attributed to strong optical confinement in the high-quality(Q)cavity.Upon the phase change of MAPbI_(3) perovskite,both its gain and dielectric constant changes dramatically,enabling a wide(Δλ>9 nm)and temperature-sensitive(0.30 nm K^(−1) rate)spectral tunability of lasing mode in the near-infrared(N-IR)region.The laser displays excellent stability,demonstrating an 80%lifetime of>2.4×107 pulses excitation.Our findings may provide a versatile platform for the next generation of tunable coherent light sources.展开更多
In this paper,we present a metamaterial structure of Dirac and vanadium dioxide(VO_(2))and investigate its optical properties using the finite-difference time-domain(FDTD)technique.Using the phase transition feature o...In this paper,we present a metamaterial structure of Dirac and vanadium dioxide(VO_(2))and investigate its optical properties using the finite-difference time-domain(FDTD)technique.Using the phase transition feature of VO_(2),the design can realize active tuning of the plasmon induced transparency(PIT)effect at terahertz frequency,thereby converting from a single PIT to a double-PIT.When VO_(2) is in the insulating state,the structure is symmetric to obtain a single-band PIT effect.When VO_(2) is in the metallic state,the structure turns asymmetric to realize a dual-band PIT effect.This design provides a reference direction for the design of actively tunable metamaterials.Additionally,it is discovered that the transparent window's resonant frequency and the Fermi level in this structure have a somewhat linear relationship.In addition,the structure achieves superior refractive index sensitivity in the terahertz band,surpassing 1 THz/RIU.Consequently,the design exhibits encouraging potential for application in refractive index sensors and optical switches.展开更多
We propose a novel approach for investigating the tunable Goos–H?nchen(GH)shift via an all-dielectric metasurface that incorporates phase change materials(PCMs).By introducing material asymmetry through the reconfigu...We propose a novel approach for investigating the tunable Goos–H?nchen(GH)shift via an all-dielectric metasurface that incorporates phase change materials(PCMs).By introducing material asymmetry through the reconfigurable characteristic of PCMs while maintaining fixed geometric parameters,we can achieve tunable dual quasi-bound states in the continuum with ultrahigh quality factors(Q factors).Enabled by such tunable dual modes with significant phase changes,the PCM-based metasurface exhibits giant-tunable bidirectional GH shifts compared to conventional metasurfaces.Notably,the GH shift exhibits multidimensional tunability,including PCM-driven switching(amorphous to crystalline),incident-angle dependence(θ),and wavelength selectivity(λ).The maximum observed shift reaches approximately 104 wavelengths,accompanied by a corresponding Q factor of 107.Our work demonstrates its potential for applications in ultrahigh-precision multifunctional devices,from biosensing to reconfigurable nanophotonic switches.展开更多
The research of long persistent luminescence(LPL)materials has yield brilliant results in many fields.However,the efforts are still needed for the regulation of the LPL performance.In this work,a series of LPL metal o...The research of long persistent luminescence(LPL)materials has yield brilliant results in many fields.However,the efforts are still needed for the regulation of the LPL performance.In this work,a series of LPL metal organic halides with rich halogen-bond interactions,Py-CdX_(2)(X=Cl,Br,I)were synthesized through self-assembly by Cd X_(2)and pyridine solvent.The steady-state emission redshifted and phosphorescence lifetime declined as the halogen atoms are aggravated.Three halides exhibit adjustable emission from blue to green and multiple phosphorescence from green to yellow at room temperature by changing the excitation wavelengths.Surprisingly,Py-CdX_(2)can emit the visible color-tunable LPL from green to yellow after removing different excitation sources at ambient conditions.Combing the results of theoretical calculation and experimental analysis,it is found that heavy atom effect and the rich intermolecular halogen bond help realize LPL and multiple triplet states originated from the pyridine ring and the halogens.展开更多
The demand of high-performance thin-film-shaped deformable electromagnetic interference(EMI)shielding devices is increasing for the next generation of wearable and miniaturized soft electronics.Although highly reflect...The demand of high-performance thin-film-shaped deformable electromagnetic interference(EMI)shielding devices is increasing for the next generation of wearable and miniaturized soft electronics.Although highly reflective conductive materials can effectively shield EMI,they prevent deformation of the devices owing to rigidity and generate secondary electromagnetic pollution simultaneously.Herein,soft and stretchable EMI shielding thin film devices with absorption-dominant EMI shielding behavior is presented.The devices consist of liquid metal(LM)layer and LM grid-patterned layer separated by a thin elastomeric film,fabricated by leveraging superior adhesion of aerosol-deposited LM on elastomer.The devices demonstrate high electromagnetic shielding effectiveness(SE)(SE_(T) of up to 75 dB)with low reflectance(SER of 1.5 dB at the resonant frequency)owing to EMI absorption induced by multiple internal reflection generated in the LM grid architectures.Remarkably,the excellent stretchability of the LM-based devices facilitates tunable EMI shielding abilities through grid space adjustment upon strain(resonant frequency shift from 81.3 to 71.3 GHz@33%strain)and is also capable of retaining shielding effectiveness even after multiple strain cycles.This newly explored device presents an advanced paradigm for powerful EMI shielding performance for next-generation smart electronics.展开更多
Nanoscale hierarchically porous metal-organic frameworks(NH-MOFs)synergistically combine the advantages of nanoscale MOFs and hierarchically porous MOFs,resulting in remarkable characteristics such as increased specif...Nanoscale hierarchically porous metal-organic frameworks(NH-MOFs)synergistically combine the advantages of nanoscale MOFs and hierarchically porous MOFs,resulting in remarkable characteristics such as increased specific surface area,greater porosity,and enhanced exposure of active sites.Herein,nanoscale hierarchically porous UIO-66(UIO-66_X)was synthesized using a defect-induced strategy that employed ethylene diamine tetraacetic acid(EDTA)as a modulator.The introduced EDTA occupies the coordination sites of organic ligands,promoting the formation and growth of UIO-66 crystal nuclei and inducing defects during synthesis.The as-synthesized UIO-66_X crystals exhibit a uniform distribution with an average size of approximately 100 nm.In addition,the total pore volume attains a remarkable value of 0.95 cm^(3)g^(-1),with mesopores constituting 36.8% of the structure.Furthermore,the porosities of UIO-66_X can be easily tuned by controlling the molar ratio of EDTA/Zr^(4+).In addition,the as-synthesized UIO-66_X exhibits excellent adsorption capacities for n-hexane(344 mg g^(-1))and pxylene(218 mg g^(-1)),which are 44.5% and 27.5% higher than those of conventional UIO-66,respectively.Finally,the adsorption behavior of n-hexane and p-xylene molecules in UIO-66_X was investigated using density functional theory simulations.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.12192251,12334014,12404378,92480001,12134001,12174113,12174107,12474325,12404379,and 12474378)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301403)+1 种基金Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)Fundamental Research Funds for the Central Universities,the Engineering Research Center for Nanophotonics&Advanced Instrument,Ministry of Education,East China Normal University(Grant No.2023nmc005).
文摘We present a compact optical delay line(ODL)with wide-range continuous tunability on thin-film lithium niobate platform.The proposed device integrates an unbalanced Mach-Zehnder interferometer(MZI)architecture with dual tunable couplers,where each coupler comprises two 2×2 multimode interferometers and a MZI phase-tuning section.Experimental results demonstrate continuous delay tuning from 0 to 293 ps through synchronized control of coupling coefficients,corresponding to a 4 cm path difference between interferometer arms.The measured delay range exhibits excellent agreement with theoretical predictions derived from ODL waveguide parameters.This result addresses critical challenges in integrated photonic systems that require precise temporal control,particularly for applications in optical communications and quantum information processing,where a wide tuning range is paramount.
基金supported by the National Key Research and Development Program of China(No.2022YFC2805200)the National Natural Science Foundation of China(No.52373094)+4 种基金Zhejiang Provincial Natural Science Foundation(No.LR25E030004)Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.2023313)Sino-German Mobility Program(No.M-0424),Ningbo Major Research and Development Plan Project(No.20241ZDYF020148)Ningbo International Cooperation(No.2023H019)Ningbo Science&Technology Bureau(No.2024QL003)。
文摘Controllably tuning the sensing performance of flexible mechanical sensors is important for them to realize on-demand sensing of various mechanical stimuli in different application scenarios.However,current regulating strategies focus on the construction process of individual sensors,the response performance of the as-formed sensors is still hard to autonomously tune with external stimulus changes like human skin.Here,we propose a new strategy that realizes post-tuning of the sensing performance by introducing a temperature-dependent phase transition elastomer into the sensing film.Through an interfacially confined photopolymerization reaction,a graphene-based phase-transition elastomeric(GPTE)film with a robust interface and excellent conductivity is well-formed at the water/air interface.Benefiting from the crystallization-melt dynamic switching in the elastomer network,the GPTE film could experience the reversible transformation between soft(1.65 MPa)and stiff(12.27MPa)states,showing huge changes of elastic modulus up to seven times near the phase transition temperature(28.5℃).Furthermore,the GPTE film is designed into a suspended perceptual configuration realizing the dynamic detection of 3D deformation adapted to temperature changes with up to 3.5-fold difference in response sensitivity.Finally,the self-adaptive sensing behavior of temperature-mediated 3D deformation is demonstrated by the effective detection of the dynamic stimulation process of cold and hot water droplets by the GPTE suspended film.The proposed strategy of phase transition-induced post-tuning of sensing performance could greatly facilitate flexible mechanical sensors towards a more intelligent one.
文摘Multiple functional metasurfaces with high information capacity have attracted considerable attention from researchers.This study proposes a 2-bit tunable spin-decoupled coded metasurface designed for the terahertz band,which utilizes the tunable properties of Dirac semimetals(DSM)to create a novel multilayer structure.By incorporating both geometric and propagating phases into the metasurface design,we can effectively control the electromagnetic wave.When the Fermi level(EF)of the DSM is set at 6 meV,the electromagnetic wave is manipulated by the gold patch embedded in the DSM film,operating at a frequency of 1.3 THz.When the EF of the DSM is set at 80 meV,the electromagnetic wave is manipulated by the DSM patch,operating at a frequency of 1.4 THz.Both modes enable independent control of beam splitting under left-rotating circularly polarized(LCP)and rightrotating circularly polarized(RCP)wave excitation,resulting in the generation of vortex beams with distinct orbital angular momentum(OAM)modes.The findings of this study hold significant potential for enhancing information capacity and polarization multiplexing techniques in wireless communications.
基金supported by the Natural Science Foundation of Jiangsu Province(Grant No.BK20240123)the National Key Research and Development Program of China(Grant No.2022YFA1405900)the National Natural Science Foundation of China(Grant Nos.12274397,12274401,and 12034018)。
文摘The excellent mechanical properties make graphene promising for realizing nanomechanical resonators with high resonant frequencies,large quality factors,strong nonlinearities,and the capability to efectively interface with various physical systems.Equipped with gate electrodes,it has been demonstrated that these exceptional device properties can be electrically manipulated,leading to a variety of nanomechanical/acoustic applications.Here,we review the recent progress of graphene nanomechanical resonators with a focus on their electrical tunability.First,we provide an overview of diferent graphene nanomechanical resonators,including their device structures,fabrication methods,and measurement setups.Then,the key mechanical properties of these devices,for example,resonant frequencies,nonlinearities,dissipations,and mode coupling mechanisms,are discussed,with their behaviors upon electrical gating being highlighted.After that,various potential classical/quantum applications based on these graphene nanomechanical resonators are reviewed.Finally,we briefy discuss challenges and opportunities in this feld to ofer future prospects for the ongoing studies on graphene nanomechanical resonators.
基金supported by Jiangsu Special Project for Frontier Leading Base Technology(Grant Nos.BK20192004)Fundamental Research Funds for Central Universities(Grant Nos.B240201190)+3 种基金Changzhou Social Development Science and Technology Support Project(Grant Nos.CE20225037)Changzhou Science and Technology Project(Grant Nos.CM20223014)Suzhou Key Industrial Technology Innovation Forward-Looking Application Research Project(Grant Nos.SYG202143)Changzhou Science and Technology Project(Grant Nos.CJ20241061).
文摘Soft actuators are inherently flexible and compliant,traits that enhance their adaptability to diverse environments and tasks.However,their low structural stiffness can lead to unpredictable and uncontrollable complex deformations when substantial force is required,compromising their load-bearing capacity.This work proposes a novel method that uses gecko setae-inspired adhesives as interlayer films to construct a layer jamming structure to adjust the stiffness of soft actuators.The mechanical behavior of a single tilted microcylinder was analyzed using the energy method to determine the adhesion force of the adhesives.The gecko-inspired adhesive was designed under the guidance of the adhesion force model.Testing under various loads and directions revealed that the tilted characteristic of microcylinders can enhance the adhesion force in its grasping direction.The adhesive demonstrated excellent adhesion performance compared to other typical adhesives.A tunable stiffness actuator using gecko setae-inspired adhesives(TSAGA),was developed with these adhesives serving as interlayer films.The stiffness model of TSAGA was derived by analyzing its axial compression force.The results of stiffness test indicate that the adhesives serve as interlayer films can adjust the stiffness in response to applied load.TSAGA was compared with other typical soft actuators in order to evaluate the stiffness performance,and the results indicate that TSAGA exhibits the highest stiffness and the widest tunable stiffness range.This demonstrates the superior performance of the setae-inspired adhesives as interlayer films in terms of stiffness adjustment.
基金supported by the National Natural Science Foundation of China(No.52192633)the Natural Science Basic Research Plan in Shaanxi Province of China(No.2025JC-YBMS-050)。
文摘Metamaterials with multistability have attracted much attention due to their extraordinary physical properties. In this paper, we report a novel multistable strategy that is reversible under external forces, based on the fact that a variational reversible locally resonant elastic metamaterial(LREM) with four configurations is proposed. Through a combination of theoretical analysis and numerical simulations, this newly designed metamaterial is proven to exhibit different bandgap ranges and vibration attenuation properties in each configuration. Especially, there is tunable anisotropy shown in these configurations, which enables the bandgaps in two directions to be separated or overlapped. A model with a bandgap shifting ratio(BSR) of 100% and an overlap ratio of 25% is set to validate the multistable strategy feasibility. The proposed design strategy demonstrates significant potentials for applications in versatile scenarios.
文摘In this paper,a tunable metamaterial absorber based on a Dirac semimetal is proposed.It consists of three different structures,from top to bottom,namely a double semicircular Dirac semimetal resonator,a silicon dioxide substrate and a continuous vanadium dioxide(VO_(2))reflector layer.When the Fermi energy level of the Dirac semimetal is 10 meV,the absorber absorbs more than 90%in the 39.06-84.76 THz range.Firstly,taking advantage of the tunability of the conductivity of the Dirac semimetal,dynamic tuning of the absorption frequency can be achieved by changing the Fermi energy level of the Dirac semimetal without the need to optimise the geometry and remanufacture the structure.Secondly,the structure has been improved by the addition of the phase change material VO_(2),resulting in a much higher absorption performance of the absorber.Since VO_(2)is a temperature-sensitive metal oxide with an insulating phase below the phase transition temperature(about 68℃)and a metallic phase above the phase transition temperature,this paper also analyses the effect of VO_(2)on the absorptive performance at different temperatures,with the aim of further improving absorber performance.
基金supported by the Key Projects of Department of Education of Hunan Province,China(Grant No.21A0167)the Natural Science Foundation of Hunan Province,China(Grant No.2019JJ40532)the Talent Introducing Foundation of Central South University of Forestry and Technology(Grant No.104-0160)。
文摘In two-dimensional bilayer systems,twist-angle-dependent electronic and thermoelectric properties have garnered significant scientific interest in recent years.In this work,based on a combination of density functional theory and nonequilibrium Green’s function method,we explore the electronic and thermoelectric properties in blue-phosphorene nanoribbon-based heterojunction(BPNRHJ)with and without blue-phosphorene nanoribbon(BPNR)stack.Our calculations find that the electronic conductance and power factor can be strongly enhanced by the BPNR stack,and their enhancements can be further observed with the twist between the layers.The main reason for this is the electronic hybridization between the layers can provide new transport channels,and the twist can modulate the strength of interlayer electronic hybridization,resulting in extremely violent fluctuations in electron transmission and hence an enhanced power factor.While the phonon thermal conductance exhibits very low dependence on the layer stack and twist.Combining these factors,our results reveal that the thermoelectric performance can be greatly modulated and enhanced in twist bilayer BPNRHJ:the figure of merit will be over 2.5 in 4-4-ZBPNR@ZGNR-AA-8.8∘at 500 K.
基金Project supported by the Natural Science Foundation of Hebei Province(B2023201108,B2024201076)Science Fund for Creative Research Groups of Natural Science Foundation of Hebei Province(B2021201038)+3 种基金333 Talent Project Fund of Hebei Province(C20221015)National High-End Foreign Expert Recruitment Plan(G2022003007L)Hebei Province Higher Education Science and Technology Research Project(JZX2023001)Hebei Province Innovation Capability Enhancement Plan Project(22567632H)。
文摘Lead-free double perovskites have gained recognition as top luminescent materials due to their environmental friendliness,high chemical stability,structural adjustability,and excellent photoelectric properties.However,the poor modulation of emission restricts their applications,and it is highly desirable to explore stable and efficient double perovskites with multimode luminescence and adjustable spectra for multifunctional photoelectric applications.Herein,the rare earth ions Ln^(3+)(Er^(3+)and Ho^(3+))-doped Cs_(2)NaYCl_(6):Sb^(3+)crystals were synthesized by a simple solvothermal route.The X-ray diffraction pattern(XRD),energy-dispersive spectroscopy(EDS),X-ray photoelectron spectroscopy(XPS),and elemental mapping images demonstrate that the Sb^(3+),Er^(3+),and Ho^(3+)ions have been homogeneously incorporated into the Cs_(2)NaYCl_(6)crystals.As anticipated,the emissio n spectra of Cs_(2)NaYCl_(6):Sb^(3+)/Ln^(3+)are composed of two bands.One broad blue band derives from self-trapped exciton(STE)in[SbCl_(6)]3-octahedra while another group of emission peaks stems from the f-f transitions of Ln^(3+)ions.The emission colors of Cs_(2)NaYCl_(6):Sb^(3+)/Ln^(3+)phosphors can be tuned in a wide range by modulating the doping concentrations of Ln^(3+)ions.The efficient energy transfer from STE to Ln^(3+)is the key point to achieving the efficient and tunable emissions Cs_(2)NaYCl_(6):Sb^(3+)/Ln^(3+)samples.Interestingly,Cs_(2)NaYCl_(6):Sb^(3+)/Ln^(3+)can also exhibit characteristic up-conversion luminescence of Ln^(3+)under nearinfrared(NIR)excitation besides the down-conversion luminescence,revealing that the materials may have potential applicability in multimode anti-counterfeiting and information encryption applications.Furthermore,the light emitting diodes(LEDs)assembled by Cs_(2)NaYCl_(6):Sb^(3+)and Cs_(2)NaYCl_(6):Sb^(3+)/Ln^(3+)phosphors display dazzling blue,green,and red emissions under a forward bias current,which indicates that the as-obtained double perovskites materials may have great potential in solid-state lighting and optoelectronic devices.
基金the National Natural Science Foundation of China(Nos.22075027,52003030)Starting Grant from Beijing Institute of Technology and financial support from the State Key Laboratory of Explosion Science and Safety Protection(Nos.YBKT2106,YBKT23-05)Beijing Institute of Technology Research Fund Program for Young Scholars。
文摘Despite significant progress has been achieved regarding the shuttle-effect of lithium polysulfides,the suppressed specific capacity and retarded redox kinetics under high sulfur loading still threat the actual energy density and power density of lithium-sulfur batteries.In this study,a graham condenser-inspired carbon@WS_(2)host with coil-in-tube structure was designed and synthesized using anodic aluminum oxide(AAO)membrane with vertically aligned nanopores as template.The vertical array of carbon nanotubes with internal carbon coils not only leads to efficient charge transfer across through the thickness of the cathode,but also provides significant confinement to polysulfide diffusion towards both the lateral and longitudinal directions.Few-layer WS_(2)in the carbon coils perform a synergistic role in suppressing the shuttle-effect as well as boosting the cathodic kinetics.As a result,high specific capacity(1180 m Ah/g at 0.1 C)and long-cycling stability at 0.5 C for 500 cycles has been achieved at 3 mgS/cm^(2).Impressive areal capacity of 7.4 m Ah/cm^(2)has been demonstrated when the sulfur loading reaches 8.4 mg/cm^(2).The unique coil-in-tube structure developed in this work provides a new solution for high sulfur loading cathode towards practical lithium-sulfur batteries.
基金financially supported by the National Natural Science Foundation of China(No.22171182)Sichuan Tianfu Emei Plan.
文摘Control crosslink network and chain connectivity are essential to develop shape memory polymers(SMPs)with high shape memory capabilities,adjustable response temperature,and satisfying mechanistical properties.In this study,novel poly(ε-caprolactone)(PCL)-poly(2-vinyl)ethylene glycol(PVEG)copolymers bearing multi-pendant vinyl groups is synthesized by branched-selective allylic etherification polymerization of vinylethylene carbonate(VEC)with linear and tetra-arm PCLs under a synergistic catalysis of palladium complex and boron reagent.Facile thiol-ene photo-click reaction of PCL-PVEG copolymers with multifunctional thiols can rapidly access a serious crosslinked SMPs with high shape memory performance.The thermal properties,mechanical properties and response temperature of the obtained SMPs are tunable by the variation of PCL prepolymers,vinyl contents and functionality of thiols.Moreover,high elastic modulus in the rubbery plateau region can be maintained effectively owing to high-density topological networks of the PCL materials.In addition,the utility of the present SMPs is further demonstrated by the post-functionalization via thiol-ene photo-click chemistry.
基金supported by the National Natural Science Foundation of China(Grant Nos.12322407,62122036,and 62034004)the Natural Science Foundation of Jiangsu Province(Grant No.BK20233001)+5 种基金the National Key R&D Program of China(Grant Nos.2023YFF0718400 and 2023YFF1203600)the Leading-edge Technology Program of Jiangsu Natural Science Foundation(Grant No.BK20232004)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB44000000)Innovation Program for Quantum Science and Technologysupport from the Fundamental Research Funds for the Central Universities(Grant Nos.020414380227,020414380240,and 020414380242)the e-Science Center of Collaborative Innovation Center of Advanced Microstructures。
文摘Layer pseudospins,exhibiting quantum coherence and precise multistate controllability,present significant potential for the advancement of future computing technologies.In this work,we propose an in-memory probabilistic computing scheme based on the electrical manipulation of layer pseudospins in layered materials,by exploiting the interaction between real spins and layer pseudospins.
基金supported by the National Natural Science Foundation of China(Grant Nos.12175315 and 12205385)。
文摘We propose a novel approach to generate and manipulate topological Floquet bound states in the continuum(BICs)via a class of systems constructed by coupling two identical periodically driven one-dimensional Su-Schrieffer-Heeger chains.The formation of topological Floquet BICs can be adjusted only by tuning the driving amplitude or frequency,regardless of whether the static system has BICs or not.The interchain bias can only change the localization property of topological Floquet BICs,and a bigger bias can lead to transforming topological Floquet BICs into bound states out of the continuum(BOCs).But it does not change the topological properties of these topological Floquet states.Based on the repulsion effect of edge states,we propose to detect occurrence of topological Floquet BICs and transition point between topological Floquet BICs and BOCs using quantum walk.Our work provided a convenient and realistic approach for the experimental realization and manipulation of BICs in a single-particle quantum system.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFA1404201)Australia Research Council(Grant Nos.DP220100603 and FT220100559)+7 种基金the National Natural Science Foundation of China(Grant No.U23A20375)the Natural Science Foundation of Shanxi Province(Grant No.202403021211011)Research Project Supported by Shanxi Scholarship Council of China(Grant No.2024-032)Fund Program for the Scientific Activities of Selected Returned Overseas Professionals in Shanxi Province(Grant No.20240006)the Program of State Key Laboratory of Quantum Optics and Quantum Optics Devices(Grant No.KF202402)Basic Scientific Research Conditions and Major Scientific Instrument and Equipment Development of Anhui Science and Technology Department(Grant No.2023YFF0715700)Key Research Project of Shanxi Province(Grant No.202302150101001)Linkage Project Scheme(Grant Nos.LP210200345 and LP210100467).
文摘Terahertz(THz)switches are essential components of THz communication systems.THz switches based on conventional waveguides and photonic crystal structures are sensitive to manufacturing defects and sharp bending,resulting in high scattering losses.In addition,THz switches with tunable working bandwidths have not yet been demonstrated.Here,we design THz switches based on a topological valley photonic crystal(VPC)structure using magnetic materials,which can achieve high forward transmittance based on the unique spin–valley locking effect.The broad working bandwidth allows selective turning on and off at a designed wavelength region by controlling the applied magnetic field.The designed THz switch can achieve an extinction ratio of up to 31.66 dB with an insertion loss of less than 0.13 dB.The 3-dB bandwidth is up to 49 GHz.This tunable THz switch can be experimentally fabricated by current fabrication techniques and thus can find broad applications in THz communication systems.
基金supported by the National Key Research and Development Program of China(2020YFA0714504,2019YFA0709100 to T.C.)the program of the National Natural Science Foundation of China(No.62105054 to T.C.)+1 种基金the New Cornerstone Science Foundation(AoE/P502/20 to S.Z.)the Research Grants Council of Hong Kong(17315522 to S.Z.).
文摘Perovskite semiconductors show great promise as gain media for all-solution-processed single-mode microlasers.However,despite the recent efforts to improve their lasing performance,achieving tunable single-mode microlasers remains challenging.In this work,we address this challenge by demonstrating a tunable vertical cavity surface emitting laser(VCSEL)employing a tunable gain medium of halide phase-change perovskites-specifically MAPbI_(3) perovskite,sandwiched between two highly reflective mirrors composed of bottom-distributed Bragg reflectors(DBRs).This VCSEL possesses single-mode lasing emission with a low threshold of 23.5μJ cm^(−2) under 160 K,attributed to strong optical confinement in the high-quality(Q)cavity.Upon the phase change of MAPbI_(3) perovskite,both its gain and dielectric constant changes dramatically,enabling a wide(Δλ>9 nm)and temperature-sensitive(0.30 nm K^(−1) rate)spectral tunability of lasing mode in the near-infrared(N-IR)region.The laser displays excellent stability,demonstrating an 80%lifetime of>2.4×107 pulses excitation.Our findings may provide a versatile platform for the next generation of tunable coherent light sources.
基金supported by the Natural Science Foundation of Chongqing of China(No.CSTB2024NSCQ-MSX0746)the Young Scientists Fund of the National Natural Science Foundation of China(No.11704053)+1 种基金the National Natural Science Foundation of China(No.52175531)the Science and Technology Research Program of Chongqing Municipal Education Commission(Nos.KJQN 201800629,KJZD-M202000602 and 62375031)。
文摘In this paper,we present a metamaterial structure of Dirac and vanadium dioxide(VO_(2))and investigate its optical properties using the finite-difference time-domain(FDTD)technique.Using the phase transition feature of VO_(2),the design can realize active tuning of the plasmon induced transparency(PIT)effect at terahertz frequency,thereby converting from a single PIT to a double-PIT.When VO_(2) is in the insulating state,the structure is symmetric to obtain a single-band PIT effect.When VO_(2) is in the metallic state,the structure turns asymmetric to realize a dual-band PIT effect.This design provides a reference direction for the design of actively tunable metamaterials.Additionally,it is discovered that the transparent window's resonant frequency and the Fermi level in this structure have a somewhat linear relationship.In addition,the structure achieves superior refractive index sensitivity in the terahertz band,surpassing 1 THz/RIU.Consequently,the design exhibits encouraging potential for application in refractive index sensors and optical switches.
基金Project supported by the National Natural Science Foundation of China(Grant No.12274225)the Fundamental Research Funds for the Central Universities(Grant No.NS2023056)+1 种基金the Natural Science Foundation of Hebei Province,China(Grant No.B2024209014)the Basic Scientific Research Project of Hebei Provincial Department of Education(Grant No.JJC2024059)。
文摘We propose a novel approach for investigating the tunable Goos–H?nchen(GH)shift via an all-dielectric metasurface that incorporates phase change materials(PCMs).By introducing material asymmetry through the reconfigurable characteristic of PCMs while maintaining fixed geometric parameters,we can achieve tunable dual quasi-bound states in the continuum with ultrahigh quality factors(Q factors).Enabled by such tunable dual modes with significant phase changes,the PCM-based metasurface exhibits giant-tunable bidirectional GH shifts compared to conventional metasurfaces.Notably,the GH shift exhibits multidimensional tunability,including PCM-driven switching(amorphous to crystalline),incident-angle dependence(θ),and wavelength selectivity(λ).The maximum observed shift reaches approximately 104 wavelengths,accompanied by a corresponding Q factor of 107.Our work demonstrates its potential for applications in ultrahigh-precision multifunctional devices,from biosensing to reconfigurable nanophotonic switches.
基金financially supported by National Natural Science Foundation of China(No.22101162)Start-up Foundation of Shaanxi University of Science&Technology(No.126022036)。
文摘The research of long persistent luminescence(LPL)materials has yield brilliant results in many fields.However,the efforts are still needed for the regulation of the LPL performance.In this work,a series of LPL metal organic halides with rich halogen-bond interactions,Py-CdX_(2)(X=Cl,Br,I)were synthesized through self-assembly by Cd X_(2)and pyridine solvent.The steady-state emission redshifted and phosphorescence lifetime declined as the halogen atoms are aggravated.Three halides exhibit adjustable emission from blue to green and multiple phosphorescence from green to yellow at room temperature by changing the excitation wavelengths.Surprisingly,Py-CdX_(2)can emit the visible color-tunable LPL from green to yellow after removing different excitation sources at ambient conditions.Combing the results of theoretical calculation and experimental analysis,it is found that heavy atom effect and the rich intermolecular halogen bond help realize LPL and multiple triplet states originated from the pyridine ring and the halogens.
基金supported by National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(RS-2024-00335216,RS-2024-00407084 and RS-2023-00207836)Korea Environment Industry&Technology Institute(KEITI)through the R&D Project of Recycling Development for Future Waste Resources Program,funded by the Korea Ministry of Environment(MOE)(2022003500003).
文摘The demand of high-performance thin-film-shaped deformable electromagnetic interference(EMI)shielding devices is increasing for the next generation of wearable and miniaturized soft electronics.Although highly reflective conductive materials can effectively shield EMI,they prevent deformation of the devices owing to rigidity and generate secondary electromagnetic pollution simultaneously.Herein,soft and stretchable EMI shielding thin film devices with absorption-dominant EMI shielding behavior is presented.The devices consist of liquid metal(LM)layer and LM grid-patterned layer separated by a thin elastomeric film,fabricated by leveraging superior adhesion of aerosol-deposited LM on elastomer.The devices demonstrate high electromagnetic shielding effectiveness(SE)(SE_(T) of up to 75 dB)with low reflectance(SER of 1.5 dB at the resonant frequency)owing to EMI absorption induced by multiple internal reflection generated in the LM grid architectures.Remarkably,the excellent stretchability of the LM-based devices facilitates tunable EMI shielding abilities through grid space adjustment upon strain(resonant frequency shift from 81.3 to 71.3 GHz@33%strain)and is also capable of retaining shielding effectiveness even after multiple strain cycles.This newly explored device presents an advanced paradigm for powerful EMI shielding performance for next-generation smart electronics.
基金financial support from the National Natural Science Foundation of China(22008032)the Guangdong Basic and Applied Basic Research Foundation(2023A1515011881,2020A1515110817,2022A1515011192,2023A1515010679,and 2020A1515110325)+1 种基金the Guangdong Provincial Key Laboratory of Intelligent Food Manufacturing(2022B1212010015,GPKLIFM-KF202206)the University Characteristic Innovation Foundation of Guangdong(2021KTSCX114 and 2022KTSCX122)。
文摘Nanoscale hierarchically porous metal-organic frameworks(NH-MOFs)synergistically combine the advantages of nanoscale MOFs and hierarchically porous MOFs,resulting in remarkable characteristics such as increased specific surface area,greater porosity,and enhanced exposure of active sites.Herein,nanoscale hierarchically porous UIO-66(UIO-66_X)was synthesized using a defect-induced strategy that employed ethylene diamine tetraacetic acid(EDTA)as a modulator.The introduced EDTA occupies the coordination sites of organic ligands,promoting the formation and growth of UIO-66 crystal nuclei and inducing defects during synthesis.The as-synthesized UIO-66_X crystals exhibit a uniform distribution with an average size of approximately 100 nm.In addition,the total pore volume attains a remarkable value of 0.95 cm^(3)g^(-1),with mesopores constituting 36.8% of the structure.Furthermore,the porosities of UIO-66_X can be easily tuned by controlling the molar ratio of EDTA/Zr^(4+).In addition,the as-synthesized UIO-66_X exhibits excellent adsorption capacities for n-hexane(344 mg g^(-1))and pxylene(218 mg g^(-1)),which are 44.5% and 27.5% higher than those of conventional UIO-66,respectively.Finally,the adsorption behavior of n-hexane and p-xylene molecules in UIO-66_X was investigated using density functional theory simulations.
