Two-dimensional(2D)materials have attracted considerable research interest due to their precisely defined properties and versatile applications.In this realm,borophene-a single atomic sheet of boron atoms arranged in ...Two-dimensional(2D)materials have attracted considerable research interest due to their precisely defined properties and versatile applications.In this realm,borophene-a single atomic sheet of boron atoms arranged in a honeycomb lattice-has emerged as a promising candidate.While borophenes were theoretically predicted to have unique structural,optical,and electronic properties,the experimental synthesis of crystalline borophene sheets was first demonstrated on metal substrates in 2015,marking a crucial milestone.Since then,research efforts have focused on controlling the synthesis of semiconducting borophene polymorphs and exploring their novel physical characteristics.This review aims to explore the potential of 2D materials,specifically borophene,in various technological fields such as batteries,supercapacitors,fuel cells,and more.The analysis emphasises meticulous scrutiny of synthesis techniques due to their fundamental importance in realising borophene's properties.Specifically,the high carrier mobilities,tuneable bandgaps,and exceptional thermal conductivity of borophene are highlighted.By providing a comprehensive outlook on the significance of borophene in advancing materials science and technologies,this review contributes to shaping the landscape of 2D material research.展开更多
Rapidly growing population,escalating urbanization,and industrialization are causing the depletion of non-renewable resources and air pollution,a silent pandemic responsible for billions of global mortalities.Sensors ...Rapidly growing population,escalating urbanization,and industrialization are causing the depletion of non-renewable resources and air pollution,a silent pandemic responsible for billions of global mortalities.Sensors are crucial vectors for monitoring the emission of various gases/volatile organic compoundsbased pollutants from various anthropogenic sources.Borophene-based nanomaterials(BNMs)are the latest two-dimensional flatlands to this emergent next-generation sensors family with exceptional and tunable physicochemical attributes characterized by high anisotropy,thermal/mechanical resilience,tunable bandgaps,light-weight,high charge carrier mobility,and excellent adsorption efficacies.However,the practical implementation and scalability of BNMs grapple with challenges,including instability,substrateto-device transfer complications,and optimization intricacies.This comprehensive review delves into state-of-the-art BNM sensor fabrication techniques,intertwining theoretical insights derived from density functional theory and molecular dynamics with practical evaluations and on-site applications.Besides,the fundamental challenges associated with engineering BNM sensors and their alternate solutions by employing various strategies,including surface termination,functionalization,hydrogenation,hybridization,architecting composites,and green chemistry,are detailed.This review offers a roadmap from lab to market,bridging theoretical insights with practical implementation and expediting the advanced BNM sensors with wearable,remotely accessible,point-of-care,scavenging,self-powered,biocompatible,and intelligent modules for pollution management.展开更多
This review provides an insightful and comprehensive exploration of the emerging 2D material borophene,both pristine and modified,emphasizing its unique attributes and potential for sustainable applications.Borophene...This review provides an insightful and comprehensive exploration of the emerging 2D material borophene,both pristine and modified,emphasizing its unique attributes and potential for sustainable applications.Borophene’s distinctive properties include its anisotropic crystal structures that contribute to its exceptional mechanical and electronic properties.The material exhibits superior electrical and thermal conductivity,surpassing many other 2D materials.Borophene’s unique atomic spin arrangements further diversify its potential application for magnetism.Surface and interface engineering,through doping,functionalization,and synthesis of hybridized and nanocomposite borophene-based systems,is crucial for tailoring borophene’s properties to specific applications.This review aims to address this knowledge gap through a comprehensive and critical analysis of different synthetic and functionalisation methods,to enhance surface reactivity by increasing active sites through doping and surface modifications.These approaches optimize diffusion pathways improving accessibility for catalytic reactions,and tailor the electronic density to tune the optical and electronic behavior.Key applications explored include energy systems(batteries,supercapacitors,and hydrogen storage),catalysis for hydrogen and oxygen evolution reactions,sensors,and optoelectronics for advanced photonic devices.The key to all these applications relies on strategies to introduce heteroatoms for tuning electronic and catalytic properties,employ chemical modifications to enhance stability and leverage borophene’s conductivity and reactivity for advanced photonics.Finally,the review addresses challenges and proposes solutions such as encapsulation,functionalization,and integration with composites to mitigate oxidation sensitivity and overcome scalability barriers,enabling sustainable,commercial-scale applications.展开更多
In the field of volatile organic compounds(VOCs)pollution control,adsorption is one of the major control methods,and effective adsorbents are desired in this technology.In this work,the density functional theory(DFT)c...In the field of volatile organic compounds(VOCs)pollution control,adsorption is one of the major control methods,and effective adsorbents are desired in this technology.In this work,the density functional theory(DFT)calculations are employed to investigate the adsorption of typical VOCs molecules on the two-dimensional material borophenes.The results demonstrate that both structure ofχBorophene;2D material;Volatile organic compounds(VOCs);Selective adsorption;Electronic structure andβ12 borophene can chemically adsorb ethylene and formaldehyde with forming chemical bonds and releasing large energy.However,other VOCs,including ethane,methanol,formic acid,methyl chloride,benzene and toluene,are physically adsorbed with weak interaction.The analysis of density of states(DOS)reveals that the chemical adsorption changes the conductivity of borophenes,while the physical adsorption has no distinct effect on the conductivity.Therefore,bothχ^(3)andβ_(12) borophene are appropriate adsorbents for selective adsorption of ethylene and formaldehyde,and they also have potential in gas sensor applications due to the obvious conductivity change during the adsorption.展开更多
The successful discovery of borophene has opened a new door for the development of 2D materials.Due to its excellent chemical,electronic and thermal properties,borophene has shown considerable potential in supercapaci...The successful discovery of borophene has opened a new door for the development of 2D materials.Due to its excellent chemical,electronic and thermal properties,borophene has shown considerable potential in supercapacitors,hydrogen storage and batteries.In this paper,the thermodynamic characteristics and magnetocaloric effect of borophene are specifically studied using the Monte Carlo method.We find that there is an opposite impact between the spin quantum number and the crystal field on the magnetization,magnetic susceptibility,specific heat and magnetic entropy of the system.Moreover,increasing the spin quantum number or decreasing the absolute value of the crystal field can improve the relative cooling power,the coercivity(h_(c)),and the remanence(M_(R))and the area of the loop.展开更多
Borophene allotropes have many unique physical properties due to their polymorphism and similarity between boron and carbon.In this work,based on the density functional theory and phonon Boltzmann transport equation,w...Borophene allotropes have many unique physical properties due to their polymorphism and similarity between boron and carbon.In this work,based on the density functional theory and phonon Boltzmann transport equation,we investigate the lattice thermal conductivityκof bothβ12 andχ3 borophene.Interestingly,these two allotropes with similar lattice structures have completely different thermal transport properties.β12 borophene has almost isotropicκaround 90 W/(m·K)at 300 K,whileκofχ3 borophene is much larger and highly anisotropic.The room temperatureκofχ3 borophene along the armchair direction is 512 W/(m·K),which is comparable to that of hexagonal boron nitride but much higher than most of the two-dimensional materials.The physical mechanisms responsible for such distinct thermal transport behavior are discussed based on the spectral phonon analysis.More interestingly,we uncover a unique one-dimensional transport feature of transverse acoustic phonon inχ3 borophene along the armchair direction,which results in a boost of phonon relaxation time and thus leads to the significant anisotropy and ultrahigh thermal conductivity inχ3 borophene.Our study suggests thatχ3 borophene may have promising application in heat dissipation,and also provides novel insights for enhancing the thermal transport in two-dimensional systems.展开更多
In recent years, two-dimensional boron sheets （borophene） have been experimentally synthesized and theoretically proposed as a promising conductor or transistor with novel thermal and electronic properties. We first...In recent years, two-dimensional boron sheets （borophene） have been experimentally synthesized and theoretically proposed as a promising conductor or transistor with novel thermal and electronic properties. We first give a general survey of some notable electronic properties of borophene, including the superconductivity and topological characters. We then mainly review the basic approaches, thermal transport, as well as the mechanical properties of borophene with different configurations. This review gives a general understanding of some of the crucial thermal transport and electronic properties of borophene, and also calls for further experimental investigations and applications on certain scientific community.展开更多
This work presents an investigation of nanoribbons cut from β_(12)-borophene sheets by applying the density functional theory. In particular, the electronic and magnetic properties of borophene nanoribbons(BNR) are s...This work presents an investigation of nanoribbons cut from β_(12)-borophene sheets by applying the density functional theory. In particular, the electronic and magnetic properties of borophene nanoribbons(BNR) are studied. It is found that all the ribbons considered in this work behave as metals, which is in good agreement with the recent experimental results. β_(12)-BNR has significant diversity due to the existence of five boron atoms in a unit cell of the sheet. The magnetic properties of the ribbons are strongly dependent on the cutting direction and edge profile. It is interesting that a ribbon with a specific width can behave as a normal or a ferromagnetic metal with magnetization at just one edge or two edges. Spin anisotropy is observed in some ribbons, and the magnetic moment is not found to be the same in both edges in an antiferromagnetic configuration. This effect stems from the edge asymmetry of the ribbons and results in the breaking of spin degeneracy in the band structure. Our findings show that β_(12) BNRs are potential candidates for next-generation spintronic devices.展开更多
Borophene is an emerging and promising twodimensional material for spintronics applications.Nevertheless,the origin and controllability of its magnetism remain poorly understood,thereby hindering the further developme...Borophene is an emerging and promising twodimensional material for spintronics applications.Nevertheless,the origin and controllability of its magnetism remain poorly understood,thereby hindering the further development of borophene-based devices.In this study,it is demonstrated that χ_(3) borophene with vacancy defects,which contains zigzag edges and dangling bonds,exhibits spin polarization.To understand the origin and characteristics of its magnetism,a magnetic study of vacancy defects in χ_(3) borophene using first-principles calculations was performed.It is determined that the unpaired dangling bond electrons in the σ state contribute to its magnetism,and the zigzagged vacancy structure helps to maintain the localization and stability of unpaired electrons.Ferromagnetic coupling is completed by the s-p orbital interaction and mediated by p-orbital itinerant electrons.The magnetic coupling energy difference oscillates with the distance of magnetic atoms because of the indirect magnetic exchange by itinerant electrons and electronic shielding,in accordance with the Ruderman-Kittel-Kasuya-Yosida(RKKY)model.Furthermore,the causality between the dangling bonds and magnetism is identified by saturating magnetic B atoms using H,C and N atoms.This study provides a reference for the regulation of borophene in magnetic semiconductors.展开更多
We investigate the collective plasma oscillations theoretically in multilayer 8-Pmmn borophene structures,where the tilted Dirac electrons in spatially separated layers are coupled via the Coulomb interaction.We calcu...We investigate the collective plasma oscillations theoretically in multilayer 8-Pmmn borophene structures,where the tilted Dirac electrons in spatially separated layers are coupled via the Coulomb interaction.We calculate the energy dispersions and Landau dampings of the multilayer plasmon excitations as a function of the total number of layers,the interlayer separation,and the different orientations.Like multilayer graphene,the plasmon spectrum in multilayer borophene consists of one in-phase optical mode and N-1 out-of-phase acoustical modes.We show that the plasmon modes possess kinks at the boundary of the interband single-particle continuum and the apparent anisotropic behavior.All the plasmon modes approach the same dispersion at a sufficiently large interlayer spacing in the short-wavelength limit.Especially along specific orientations,the optical mode could touch an energy maximum in the nondamping region,which shows non-monotonous behavior.Our work provides an understanding of the multilayer borophene plasmon and may pave the way for multilayer borophene-based plasmonic devices.展开更多
Near-field radiative heat transfer(NFRHT)has the potential to exceed the blackbody limit by several orders of magnitude,offering significant opportunities for energy harvesting.In this study,we have examined the NFRHT...Near-field radiative heat transfer(NFRHT)has the potential to exceed the blackbody limit by several orders of magnitude,offering significant opportunities for energy harvesting.In this study,we have examined the NFRHT between two borophene sheets through the calculation of heat transfer coefficient(HTC).Due to the tunneling of evanescent waves,borophene sheet allows for enhanced heat flux and adjustable NFRHT by varying its electron density and electron relaxation time.Additionally,the near field coupling is further examined when the borophene is deposited on dielectric or lossy substrates.The maximum HTC is closely related to the real part of the dielectric substrate.As a case study,the HTCs on the lossy substrate of MoO_(3),ZnSe,and SiC are calculated for comparisons.Our results indicate that MoO_(3)is the optimal substrate to get the enhanced energy transfer coefficient.It results in a remarkable value of 1737 times higher than the blackbody limit owing to the enhanced photon tunneling probability.Thus,our study reveals the effect of substrate on the HTC between borophene sheets and provides a theoretical guidance for the design of near-field thermal radiation devices.展开更多
By applying the first principles calculations combined with density functional theory (DFT), this study explored the optical properties, electronic structure, and structure stability of triangular borophene decorated ...By applying the first principles calculations combined with density functional theory (DFT), this study explored the optical properties, electronic structure, and structure stability of triangular borophene decorated chemically, B3X (X=F, Cl) in a systematical manner. As revealed from the results of formation energy, phonon dispersion, and molecular dynamics simulation study, all the borophene decorated chemically were superior and able to be fabricated. In the present study, triangular borophene was reported to be converted into Dirac-like materials when functionalized by F and Cl exhibiting narrow direct band gaps as 0.19 eV and 0.17 eV, separately. Significant light absorption was assessed in the visible light and ultraviolet region. According the mentioned findings, these two-dimensional (2D) materials show large and wide promising applications for future nanoelectronics and optoelectronics.展开更多
The present work carries out molecular dynamics simulations to compute the thermal conductivity of the borophene nanoribbon and the borophene nanotube using the Müller-Plathe approach.We investigate the thermal condu...The present work carries out molecular dynamics simulations to compute the thermal conductivity of the borophene nanoribbon and the borophene nanotube using the Müller-Plathe approach.We investigate the thermal conductivity of the armchair and zigzag borophenes,and show the strong anisotropic thermal conductivity property of borophene.We compare results of the borophene nanoribbon and the borophene nanotube,and find the thermal conductivity of the borophene is orientation dependent.The thermal conductivity of the borophene does not vary as changing the width of the borophene nanoribbon and the perimeter of the borophene nanotube.In addition,the thermal conductivity of the borophene is not sensitive to the applied strains and the background temperatures.展开更多
The integration of two-dimensional(2D)materials into metal matrices represents a compelling strategy for creating next-generation structural materials with synergistic mechanical and functional properties.Among these,...The integration of two-dimensional(2D)materials into metal matrices represents a compelling strategy for creating next-generation structural materials with synergistic mechanical and functional properties.Among these,borophene offers exceptional theoretical stiffness(398 N/m),tunable electrical character,and structural polymorphism.However,the scalable synthesis of crystalline borophene and its practical integration into metal matrices remain formidable challenges.Here,we report a breakthrough bottom-up strategy for the controlled chemical vapor deposition(CVD)of large-scale,single-crystallineα'-4H-borophene directly on Cu(111)surface using B2H6 gas.By controlling growth kinetics,a dendritic borophene morphology is obtained to promote mechanical interlocking.This in-situ fabrication creates an integrated borophene/copper composite,exhibiting a remarkable simultaneous enhancement in both strength and stiffness.Compared with pristine copper,the borophene-reinforced composites show significant mechanical enhancements:an increase of 71%in Young’s modulus(113.5 to 194.3 GPa),a higher yield strength of 323%(69 to 292 MPa),and a greater ultimate tensile strength of 43%(228 to 325 MPa).These improvements exceed those of other reported 2D material-reinforced Cu composites,establishing borophene’s potential for structural applications and offering a novel synthesis pathway for advanced metal-matrix composites reinforced with 2D materials.展开更多
We report the successful preparation of a purely honeycomb,graphene-like borophene,by using an Al(11 1) surface as the substrate and molecular beam epitaxy(MBE) growth in ultrahigh vacuum.Scanning tunneling microscopy...We report the successful preparation of a purely honeycomb,graphene-like borophene,by using an Al(11 1) surface as the substrate and molecular beam epitaxy(MBE) growth in ultrahigh vacuum.Scanning tunneling microscopy(STM) images reveal perfect monolayer borophene with planar,non-buckled honeycomb lattice similar as graphene.Theoretical calculations show that the honeycomb borophene on Al(1 1 1) is energetically stable.Remarkably,nearly one electron charge is transferred to each boron atom from the Al(1 1 1) substrate and stabilizes the honeycomb borophene structure,in contrast to the negligible charge transfer in case of borophene/Ag(1 1 1).The existence of honeycomb 2 D allotrope is important to the basic understanding of boron chemistry,and it also provides an ideal platform for fabricating boron-based materials with intriguing electronic properties such as Dirac states.展开更多
Heterostructure has triggered a surge of interest due to its synergistic effects between two different layers,which contributes to desirable physical properties for extensive potential applications.Structurally stable...Heterostructure has triggered a surge of interest due to its synergistic effects between two different layers,which contributes to desirable physical properties for extensive potential applications.Structurally stable borophene is becoming a promising candidate for constructing two-dimensional(2D)heterostructures,but it is rarely prepared by suitable synthesis conditions experimentally.Here,we demonstrate that a novel heterostructure composed of hydrogenated borophene and graphene can be prepared by heating the mixture of sodium borohydride and few-layered graphene followed by stepwise and in situ thermal decomposition of sodium borohydride under high-purity hydrogen as the carrier gas.The fabricated borophene–graphene heterostructure humidity sensor shows ultrahigh sensitivity,fast response,and long-time stability.The sensitivity of the fabricated borophene-based sensor is near 700 times higher than that of pristine graphene one at the relative humidity of 85%RH.The sensitivity of the sensor is highest among all the reported chemiresistive sensors based on 2D materials.Besides,the performance of the borophene–graphene flexible sensor maintains good stability after bending,which shows that the borophene-based heterostructures can be applied in wearable electronics.The observed high performance can be ascribed to the well-established charge transfer mechanism upon H2O molecule adsorption.This study further promotes the fundamental studies of interfacial effects and interactions between boron-based 2D heterostructures and chemical species.展开更多
High-performance gas sensing devices have been extensively studied in industrial production,clinical medicine and environmental monitoring.Among the materials used to fabricate gas sensors,two-dimensional(2D)materials...High-performance gas sensing devices have been extensively studied in industrial production,clinical medicine and environmental monitoring.Among the materials used to fabricate gas sensors,two-dimensional(2D)materials are viewed as favorable candidate sensing materials because of their high surface-to-volume ratios,abundant surface activity,defect sites.However,gas sensors based on the previously reported 2D materials have some disadvantages such as poor air-stability and slow dynamic response.Recently,borophene,as a unique 2D material,has been theoretically predicted to have excellent gas sensing characteristic,especially for nitrogen dioxide(NO_(2)).However,the gas sensing property of borophene has not been still reported experimentally.Here,we report that a chemiresistive sensor device based on borophene shows high sensitivity,fast response,high selectivity,good flexibility and long-time stability.It is found that the sensor has a low experimental detection limit of around 200 ppb,a large detection range from 200 ppb to 100 ppm,and fast response time of 30 s and recovery time of 200 s at room temperature,which are remarkably superior to those of reported 2D materials.The underlying NO_(2) sensing mechanism of borophene is revealed by first-principles calculations.In line with theoretical predication,it has also been confirmed experimentally that the borophene-based sensor has a unique selectivity to NO_(2) compared with other common gases.Furthermore,the sensor also displays superior flexibility and stability under different bending angles.This study shows excellent electronic and sensing characteristic of borophene,which indicates that it has great potential application value in high-performance sensing and detection in the future.展开更多
Density functional theory calculations and ab initio molecular dynamics simulations are performed to study the feasibility of using borophene, a newly synthesized two-dimensional sheet of boron, as an anode material f...Density functional theory calculations and ab initio molecular dynamics simulations are performed to study the feasibility of using borophene, a newly synthesized two-dimensional sheet of boron, as an anode material for sodium-ion and sodium-oxygen batteries. The theo- retical capacity of borophene is found to be as high as 1,218 mAh g-1 （Nao.sB）. More importantly, it is demonstrated that the sodium diffusion energy barrier along the valley direction is as low as 0.0019 eV, which corresponds to a diffusivity of more than a thousand times higher than that of conventional anode materials such as Na2Ti307 and Na3Sb. Hence, the use of borophene will revolutionize the rate capability of sodium-based batteries. Moreover, it is predicted that, during the sodiation process, the average open-circuit voltage is 0.53 V, which can effectively sup- press the formation of dendrites while maximizing the energy density. The metallic feature and structural integrity of borophene can be well preserved at different sodium concentrations, demonstrating good electronic conductivity and stable cyclability.展开更多
Boron-based 2D materials are of current interest.However,graphene-like geometry is unstable for B due to the electron deficiency,which can be stabilized by introducing H,F and Cl.Here,using density functional theory c...Boron-based 2D materials are of current interest.However,graphene-like geometry is unstable for B due to the electron deficiency,which can be stabilized by introducing H,F and Cl.Here,using density functional theory combined with phonon Boltzmann transport equation,we perform systematic studies on how the functionalization changes the lattice thermal conductivity(LTC).We find that when going from hydrogenation to fluorination and chlorination,the LTC along zigzag direction changes from 367.6 to 211.3 and 43.0 W/(rrvK),while the corresponding values in armchair direction are 279.6,198.9,and 41.6 W/(m·K),respectively.These huge differences imply the sensitivity of LTC to functionalization,which can be attributed to the enhanced anharmonicity as revealed by analyzing group velocity,Gruneisen parameter,anharmonic scattering rates,and three-phonon scattering space.展开更多
Monolayer boron-based materials are of current interests due to its polymorphism.Herein,motivated by the recent experimental synthesis of semiconducting hydrogenatedαʹ-borophene and the regulation of the physical pro...Monolayer boron-based materials are of current interests due to its polymorphism.Herein,motivated by the recent experimental synthesis of semiconducting hydrogenatedαʹ-borophene and the regulation of the physical properties in layered materials by surface functionalization,we study the thermal and electronic properties ofαʹ-borophene with three different types of gas functional groups(H,F,and Cl)based on first-principles and Boltzmann transport theory.It is found thatαʹ-borophene can be well stabilized by fluorination and chlorination and maintain the semiconductor nature.More interestingly,when hydrogen is replaced with fluorine or chlorine,the lattice thermal conductivity changes from 24.3 to 5.2 or 0.73 W/(m·K)along armchair direction at 300 K,exhibiting a huge reduction by two orders of magnitude.The main reason is the decrease of both phonon group velocities and acoustic phonon relaxation time resulting from the strong phonon mode softening due to the weaken B-B bond strength and heavier atomic mass of fluorine and chlorine.Consequently,the chlorinatedαʹ-borophene exhibits a high thermoelectric figure of merit~2 at 300 K along armchair direction.Our study illustrates the importance of the modulation of transport properties by gas functional groups,which may promote the thermoelectric application of boron-based materials.展开更多
文摘Two-dimensional(2D)materials have attracted considerable research interest due to their precisely defined properties and versatile applications.In this realm,borophene-a single atomic sheet of boron atoms arranged in a honeycomb lattice-has emerged as a promising candidate.While borophenes were theoretically predicted to have unique structural,optical,and electronic properties,the experimental synthesis of crystalline borophene sheets was first demonstrated on metal substrates in 2015,marking a crucial milestone.Since then,research efforts have focused on controlling the synthesis of semiconducting borophene polymorphs and exploring their novel physical characteristics.This review aims to explore the potential of 2D materials,specifically borophene,in various technological fields such as batteries,supercapacitors,fuel cells,and more.The analysis emphasises meticulous scrutiny of synthesis techniques due to their fundamental importance in realising borophene's properties.Specifically,the high carrier mobilities,tuneable bandgaps,and exceptional thermal conductivity of borophene are highlighted.By providing a comprehensive outlook on the significance of borophene in advancing materials science and technologies,this review contributes to shaping the landscape of 2D material research.
文摘Rapidly growing population,escalating urbanization,and industrialization are causing the depletion of non-renewable resources and air pollution,a silent pandemic responsible for billions of global mortalities.Sensors are crucial vectors for monitoring the emission of various gases/volatile organic compoundsbased pollutants from various anthropogenic sources.Borophene-based nanomaterials(BNMs)are the latest two-dimensional flatlands to this emergent next-generation sensors family with exceptional and tunable physicochemical attributes characterized by high anisotropy,thermal/mechanical resilience,tunable bandgaps,light-weight,high charge carrier mobility,and excellent adsorption efficacies.However,the practical implementation and scalability of BNMs grapple with challenges,including instability,substrateto-device transfer complications,and optimization intricacies.This comprehensive review delves into state-of-the-art BNM sensor fabrication techniques,intertwining theoretical insights derived from density functional theory and molecular dynamics with practical evaluations and on-site applications.Besides,the fundamental challenges associated with engineering BNM sensors and their alternate solutions by employing various strategies,including surface termination,functionalization,hydrogenation,hybridization,architecting composites,and green chemistry,are detailed.This review offers a roadmap from lab to market,bridging theoretical insights with practical implementation and expediting the advanced BNM sensors with wearable,remotely accessible,point-of-care,scavenging,self-powered,biocompatible,and intelligent modules for pollution management.
基金the Engineering and Physical Sciences Research Council(EPSRC)for funding the researchUK India Education Research Initiative(UKIERI)for funding support.
文摘This review provides an insightful and comprehensive exploration of the emerging 2D material borophene,both pristine and modified,emphasizing its unique attributes and potential for sustainable applications.Borophene’s distinctive properties include its anisotropic crystal structures that contribute to its exceptional mechanical and electronic properties.The material exhibits superior electrical and thermal conductivity,surpassing many other 2D materials.Borophene’s unique atomic spin arrangements further diversify its potential application for magnetism.Surface and interface engineering,through doping,functionalization,and synthesis of hybridized and nanocomposite borophene-based systems,is crucial for tailoring borophene’s properties to specific applications.This review aims to address this knowledge gap through a comprehensive and critical analysis of different synthetic and functionalisation methods,to enhance surface reactivity by increasing active sites through doping and surface modifications.These approaches optimize diffusion pathways improving accessibility for catalytic reactions,and tailor the electronic density to tune the optical and electronic behavior.Key applications explored include energy systems(batteries,supercapacitors,and hydrogen storage),catalysis for hydrogen and oxygen evolution reactions,sensors,and optoelectronics for advanced photonic devices.The key to all these applications relies on strategies to introduce heteroatoms for tuning electronic and catalytic properties,employ chemical modifications to enhance stability and leverage borophene’s conductivity and reactivity for advanced photonics.Finally,the review addresses challenges and proposes solutions such as encapsulation,functionalization,and integration with composites to mitigate oxidation sensitivity and overcome scalability barriers,enabling sustainable,commercial-scale applications.
基金supported by the National Natural Science Foundation of China(Nos.21777033 and 41807191)Science and Technology Planning Project of Guangdong Province(No.2017B020216003)+2 种基金Natural Science Foundation of Guangdong Province,China(No.2018A030310524)Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(No.2017BT01Z032)the Innovation Team Project of Guangdong Provincial Department of Education(No.2017KCXTD012)。
文摘In the field of volatile organic compounds(VOCs)pollution control,adsorption is one of the major control methods,and effective adsorbents are desired in this technology.In this work,the density functional theory(DFT)calculations are employed to investigate the adsorption of typical VOCs molecules on the two-dimensional material borophenes.The results demonstrate that both structure ofχBorophene;2D material;Volatile organic compounds(VOCs);Selective adsorption;Electronic structure andβ12 borophene can chemically adsorb ethylene and formaldehyde with forming chemical bonds and releasing large energy.However,other VOCs,including ethane,methanol,formic acid,methyl chloride,benzene and toluene,are physically adsorbed with weak interaction.The analysis of density of states(DOS)reveals that the chemical adsorption changes the conductivity of borophenes,while the physical adsorption has no distinct effect on the conductivity.Therefore,bothχ^(3)andβ_(12) borophene are appropriate adsorbents for selective adsorption of ethylene and formaldehyde,and they also have potential in gas sensor applications due to the obvious conductivity change during the adsorption.
文摘The successful discovery of borophene has opened a new door for the development of 2D materials.Due to its excellent chemical,electronic and thermal properties,borophene has shown considerable potential in supercapacitors,hydrogen storage and batteries.In this paper,the thermodynamic characteristics and magnetocaloric effect of borophene are specifically studied using the Monte Carlo method.We find that there is an opposite impact between the spin quantum number and the crystal field on the magnetization,magnetic susceptibility,specific heat and magnetic entropy of the system.Moreover,increasing the spin quantum number or decreasing the absolute value of the crystal field can improve the relative cooling power,the coercivity(h_(c)),and the remanence(M_(R))and the area of the loop.
基金Project supported in part by the National Key Research and Development Program of China(Grant No.2016YFA0200901)the National Natural Science Foundation of China(Grant No.11890703)+2 种基金the Science and Technology Commission of Shanghai Municipality,China(Grant Nos.19ZR1478600 and18JC1410900)the Fundamental Research Funds for the Central Universities,China(Grant No.22120200069)the Open Fund of Hunan Provincial Key Laboratory of Advanced Materials for New Energy Storage and Conversion(Grant No.2018TP1037201901)。
文摘Borophene allotropes have many unique physical properties due to their polymorphism and similarity between boron and carbon.In this work,based on the density functional theory and phonon Boltzmann transport equation,we investigate the lattice thermal conductivityκof bothβ12 andχ3 borophene.Interestingly,these two allotropes with similar lattice structures have completely different thermal transport properties.β12 borophene has almost isotropicκaround 90 W/(m·K)at 300 K,whileκofχ3 borophene is much larger and highly anisotropic.The room temperatureκofχ3 borophene along the armchair direction is 512 W/(m·K),which is comparable to that of hexagonal boron nitride but much higher than most of the two-dimensional materials.The physical mechanisms responsible for such distinct thermal transport behavior are discussed based on the spectral phonon analysis.More interestingly,we uncover a unique one-dimensional transport feature of transverse acoustic phonon inχ3 borophene along the armchair direction,which results in a boost of phonon relaxation time and thus leads to the significant anisotropy and ultrahigh thermal conductivity inχ3 borophene.Our study suggests thatχ3 borophene may have promising application in heat dissipation,and also provides novel insights for enhancing the thermal transport in two-dimensional systems.
文摘In recent years, two-dimensional boron sheets （borophene） have been experimentally synthesized and theoretically proposed as a promising conductor or transistor with novel thermal and electronic properties. We first give a general survey of some notable electronic properties of borophene, including the superconductivity and topological characters. We then mainly review the basic approaches, thermal transport, as well as the mechanical properties of borophene with different configurations. This review gives a general understanding of some of the crucial thermal transport and electronic properties of borophene, and also calls for further experimental investigations and applications on certain scientific community.
文摘This work presents an investigation of nanoribbons cut from β_(12)-borophene sheets by applying the density functional theory. In particular, the electronic and magnetic properties of borophene nanoribbons(BNR) are studied. It is found that all the ribbons considered in this work behave as metals, which is in good agreement with the recent experimental results. β_(12)-BNR has significant diversity due to the existence of five boron atoms in a unit cell of the sheet. The magnetic properties of the ribbons are strongly dependent on the cutting direction and edge profile. It is interesting that a ribbon with a specific width can behave as a normal or a ferromagnetic metal with magnetization at just one edge or two edges. Spin anisotropy is observed in some ribbons, and the magnetic moment is not found to be the same in both edges in an antiferromagnetic configuration. This effect stems from the edge asymmetry of the ribbons and results in the breaking of spin degeneracy in the band structure. Our findings show that β_(12) BNRs are potential candidates for next-generation spintronic devices.
基金financially supported by the Science and Technology Innovation Commission of Shenzhen (Nos.JCYJ20180507181858539 and JCYJ20190808173815205)Guangdong Basic and Applied Basic Research Foundation (No. 2019A1515012111)+1 种基金the National Key R&D Program of China (No. 2019YFB2204500)Shenzhen Science and Technology Program (No.KQTD20180412181422399)。
文摘Borophene is an emerging and promising twodimensional material for spintronics applications.Nevertheless,the origin and controllability of its magnetism remain poorly understood,thereby hindering the further development of borophene-based devices.In this study,it is demonstrated that χ_(3) borophene with vacancy defects,which contains zigzag edges and dangling bonds,exhibits spin polarization.To understand the origin and characteristics of its magnetism,a magnetic study of vacancy defects in χ_(3) borophene using first-principles calculations was performed.It is determined that the unpaired dangling bond electrons in the σ state contribute to its magnetism,and the zigzagged vacancy structure helps to maintain the localization and stability of unpaired electrons.Ferromagnetic coupling is completed by the s-p orbital interaction and mediated by p-orbital itinerant electrons.The magnetic coupling energy difference oscillates with the distance of magnetic atoms because of the indirect magnetic exchange by itinerant electrons and electronic shielding,in accordance with the Ruderman-Kittel-Kasuya-Yosida(RKKY)model.Furthermore,the causality between the dangling bonds and magnetism is identified by saturating magnetic B atoms using H,C and N atoms.This study provides a reference for the regulation of borophene in magnetic semiconductors.
基金supported by the Scientific Research Program from Science and Technology Bureau of Chongqing City(Grant No.cstc2020jcyj-msxmX0684)the Science and Technology Research Program of Chongqing Municipal Education Commission(Grant No.KJQN202000639)in part by the National Natural Science Foundation of China(Grant No.12147102)。
文摘We investigate the collective plasma oscillations theoretically in multilayer 8-Pmmn borophene structures,where the tilted Dirac electrons in spatially separated layers are coupled via the Coulomb interaction.We calculate the energy dispersions and Landau dampings of the multilayer plasmon excitations as a function of the total number of layers,the interlayer separation,and the different orientations.Like multilayer graphene,the plasmon spectrum in multilayer borophene consists of one in-phase optical mode and N-1 out-of-phase acoustical modes.We show that the plasmon modes possess kinks at the boundary of the interband single-particle continuum and the apparent anisotropic behavior.All the plasmon modes approach the same dispersion at a sufficiently large interlayer spacing in the short-wavelength limit.Especially along specific orientations,the optical mode could touch an energy maximum in the nondamping region,which shows non-monotonous behavior.Our work provides an understanding of the multilayer borophene plasmon and may pave the way for multilayer borophene-based plasmonic devices.
基金Project supported by the Natural Science Foundation of Henan Province,China(Grant No.232102231023)。
文摘Near-field radiative heat transfer(NFRHT)has the potential to exceed the blackbody limit by several orders of magnitude,offering significant opportunities for energy harvesting.In this study,we have examined the NFRHT between two borophene sheets through the calculation of heat transfer coefficient(HTC).Due to the tunneling of evanescent waves,borophene sheet allows for enhanced heat flux and adjustable NFRHT by varying its electron density and electron relaxation time.Additionally,the near field coupling is further examined when the borophene is deposited on dielectric or lossy substrates.The maximum HTC is closely related to the real part of the dielectric substrate.As a case study,the HTCs on the lossy substrate of MoO_(3),ZnSe,and SiC are calculated for comparisons.Our results indicate that MoO_(3)is the optimal substrate to get the enhanced energy transfer coefficient.It results in a remarkable value of 1737 times higher than the blackbody limit owing to the enhanced photon tunneling probability.Thus,our study reveals the effect of substrate on the HTC between borophene sheets and provides a theoretical guidance for the design of near-field thermal radiation devices.
基金Project supported by the National Natural Science Foundation of China(Grant No.11947006)the Cultivating Project for Young Scholar at Hubei University of Medicine,China(Grant No.2018QDJZR22).
文摘By applying the first principles calculations combined with density functional theory (DFT), this study explored the optical properties, electronic structure, and structure stability of triangular borophene decorated chemically, B3X (X=F, Cl) in a systematical manner. As revealed from the results of formation energy, phonon dispersion, and molecular dynamics simulation study, all the borophene decorated chemically were superior and able to be fabricated. In the present study, triangular borophene was reported to be converted into Dirac-like materials when functionalized by F and Cl exhibiting narrow direct band gaps as 0.19 eV and 0.17 eV, separately. Significant light absorption was assessed in the visible light and ultraviolet region. According the mentioned findings, these two-dimensional (2D) materials show large and wide promising applications for future nanoelectronics and optoelectronics.
基金The authors would like to thank the support by the National NSF of China(Grant Nos.11902263,11572251 and 11872309)Shaanxi Science Foundation(Grant No.2019JQ-623)+3 种基金the Fundamental Research Funds for the Central Universities(Grant Nos.310201906zy004 and 3102017jc01003)Zhang Y.was supported in part by the PECASE award N00014-16-1-2254(USA)NSF CAREER Award OCI-1149591(USA)NSF USA grant CBET-1804929.
文摘The present work carries out molecular dynamics simulations to compute the thermal conductivity of the borophene nanoribbon and the borophene nanotube using the Müller-Plathe approach.We investigate the thermal conductivity of the armchair and zigzag borophenes,and show the strong anisotropic thermal conductivity property of borophene.We compare results of the borophene nanoribbon and the borophene nanotube,and find the thermal conductivity of the borophene is orientation dependent.The thermal conductivity of the borophene does not vary as changing the width of the borophene nanoribbon and the perimeter of the borophene nanotube.In addition,the thermal conductivity of the borophene is not sensitive to the applied strains and the background temperatures.
基金supported by the National Natural Science Foundation of China(No.61774085)the Research Fund of State Key Laboratory of Mechanics and Control for Aerospace Structures(Nos.MCAS-I-0425G01 and MCAS-IS-0124K01)+1 种基金the Fundamental Research Funds for the Central Universities(No.YQR23095)the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘The integration of two-dimensional(2D)materials into metal matrices represents a compelling strategy for creating next-generation structural materials with synergistic mechanical and functional properties.Among these,borophene offers exceptional theoretical stiffness(398 N/m),tunable electrical character,and structural polymorphism.However,the scalable synthesis of crystalline borophene and its practical integration into metal matrices remain formidable challenges.Here,we report a breakthrough bottom-up strategy for the controlled chemical vapor deposition(CVD)of large-scale,single-crystallineα'-4H-borophene directly on Cu(111)surface using B2H6 gas.By controlling growth kinetics,a dendritic borophene morphology is obtained to promote mechanical interlocking.This in-situ fabrication creates an integrated borophene/copper composite,exhibiting a remarkable simultaneous enhancement in both strength and stiffness.Compared with pristine copper,the borophene-reinforced composites show significant mechanical enhancements:an increase of 71%in Young’s modulus(113.5 to 194.3 GPa),a higher yield strength of 323%(69 to 292 MPa),and a greater ultimate tensile strength of 43%(228 to 325 MPa).These improvements exceed those of other reported 2D material-reinforced Cu composites,establishing borophene’s potential for structural applications and offering a novel synthesis pathway for advanced metal-matrix composites reinforced with 2D materials.
基金supported by the National Key Research and Development Program(2016YFA0300904 and 2016YFA0202301)the National Natural Science Foundation of China(11334011,11674366 and 11674368)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB07010200 and XDPB06)
文摘We report the successful preparation of a purely honeycomb,graphene-like borophene,by using an Al(11 1) surface as the substrate and molecular beam epitaxy(MBE) growth in ultrahigh vacuum.Scanning tunneling microscopy(STM) images reveal perfect monolayer borophene with planar,non-buckled honeycomb lattice similar as graphene.Theoretical calculations show that the honeycomb borophene on Al(1 1 1) is energetically stable.Remarkably,nearly one electron charge is transferred to each boron atom from the Al(1 1 1) substrate and stabilizes the honeycomb borophene structure,in contrast to the negligible charge transfer in case of borophene/Ag(1 1 1).The existence of honeycomb 2 D allotrope is important to the basic understanding of boron chemistry,and it also provides an ideal platform for fabricating boron-based materials with intriguing electronic properties such as Dirac states.
基金This work was supported by the National Natural Science Foundation of China(No.61774085)the Natural Science Foundation of Jiangsu Province(No.BK20201300)+2 种基金the Six Talent Peaks Project in Jiangsu Province(No.XCL-046)the Research Fund of State Key Laboratory of Mechanics and Control of Mechanical Structures(NUAA)(No.MCMS-I0420G02)the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Heterostructure has triggered a surge of interest due to its synergistic effects between two different layers,which contributes to desirable physical properties for extensive potential applications.Structurally stable borophene is becoming a promising candidate for constructing two-dimensional(2D)heterostructures,but it is rarely prepared by suitable synthesis conditions experimentally.Here,we demonstrate that a novel heterostructure composed of hydrogenated borophene and graphene can be prepared by heating the mixture of sodium borohydride and few-layered graphene followed by stepwise and in situ thermal decomposition of sodium borohydride under high-purity hydrogen as the carrier gas.The fabricated borophene–graphene heterostructure humidity sensor shows ultrahigh sensitivity,fast response,and long-time stability.The sensitivity of the fabricated borophene-based sensor is near 700 times higher than that of pristine graphene one at the relative humidity of 85%RH.The sensitivity of the sensor is highest among all the reported chemiresistive sensors based on 2D materials.Besides,the performance of the borophene–graphene flexible sensor maintains good stability after bending,which shows that the borophene-based heterostructures can be applied in wearable electronics.The observed high performance can be ascribed to the well-established charge transfer mechanism upon H2O molecule adsorption.This study further promotes the fundamental studies of interfacial effects and interactions between boron-based 2D heterostructures and chemical species.
基金the National Natural Science Foundation of China(No.61774085)Natural Science Foundation of Jiangsu Province(No.BK20201300)+2 种基金Six Talent Peaks Project in Jiangsu Province(XCL-046)the Research Fund of State Key Laboratory of Mechanics and Control of Mechanical Structures(NUAA)(MCMS-I-0420G02)the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘High-performance gas sensing devices have been extensively studied in industrial production,clinical medicine and environmental monitoring.Among the materials used to fabricate gas sensors,two-dimensional(2D)materials are viewed as favorable candidate sensing materials because of their high surface-to-volume ratios,abundant surface activity,defect sites.However,gas sensors based on the previously reported 2D materials have some disadvantages such as poor air-stability and slow dynamic response.Recently,borophene,as a unique 2D material,has been theoretically predicted to have excellent gas sensing characteristic,especially for nitrogen dioxide(NO_(2)).However,the gas sensing property of borophene has not been still reported experimentally.Here,we report that a chemiresistive sensor device based on borophene shows high sensitivity,fast response,high selectivity,good flexibility and long-time stability.It is found that the sensor has a low experimental detection limit of around 200 ppb,a large detection range from 200 ppb to 100 ppm,and fast response time of 30 s and recovery time of 200 s at room temperature,which are remarkably superior to those of reported 2D materials.The underlying NO_(2) sensing mechanism of borophene is revealed by first-principles calculations.In line with theoretical predication,it has also been confirmed experimentally that the borophene-based sensor has a unique selectivity to NO_(2) compared with other common gases.Furthermore,the sensor also displays superior flexibility and stability under different bending angles.This study shows excellent electronic and sensing characteristic of borophene,which indicates that it has great potential application value in high-performance sensing and detection in the future.
基金supported by a Grant from the Research Grants Council of the Hong Kong Special Administrative Region,China(16213414)
文摘Density functional theory calculations and ab initio molecular dynamics simulations are performed to study the feasibility of using borophene, a newly synthesized two-dimensional sheet of boron, as an anode material for sodium-ion and sodium-oxygen batteries. The theo- retical capacity of borophene is found to be as high as 1,218 mAh g-1 （Nao.sB）. More importantly, it is demonstrated that the sodium diffusion energy barrier along the valley direction is as low as 0.0019 eV, which corresponds to a diffusivity of more than a thousand times higher than that of conventional anode materials such as Na2Ti307 and Na3Sb. Hence, the use of borophene will revolutionize the rate capability of sodium-based batteries. Moreover, it is predicted that, during the sodiation process, the average open-circuit voltage is 0.53 V, which can effectively sup- press the formation of dendrites while maximizing the energy density. The metallic feature and structural integrity of borophene can be well preserved at different sodium concentrations, demonstrating good electronic conductivity and stable cyclability.
基金This work is partially supported by grants from the National Natural Science Foundation of China(Nos.21773003,21973001)from the Ministry of Science and Technology of China(No.2017YFA0204902).Calculations are performed on the High Performance Computing Platform of Peking University,China.
文摘Boron-based 2D materials are of current interest.However,graphene-like geometry is unstable for B due to the electron deficiency,which can be stabilized by introducing H,F and Cl.Here,using density functional theory combined with phonon Boltzmann transport equation,we perform systematic studies on how the functionalization changes the lattice thermal conductivity(LTC).We find that when going from hydrogenation to fluorination and chlorination,the LTC along zigzag direction changes from 367.6 to 211.3 and 43.0 W/(rrvK),while the corresponding values in armchair direction are 279.6,198.9,and 41.6 W/(m·K),respectively.These huge differences imply the sensitivity of LTC to functionalization,which can be attributed to the enhanced anharmonicity as revealed by analyzing group velocity,Gruneisen parameter,anharmonic scattering rates,and three-phonon scattering space.
基金This project is supported in part by the grants from the National Natural Science Foundation of China(Nos.12075168 and 11890703)the Science and Technology Commission of Shanghai Municipality(No.19ZR1478600).
文摘Monolayer boron-based materials are of current interests due to its polymorphism.Herein,motivated by the recent experimental synthesis of semiconducting hydrogenatedαʹ-borophene and the regulation of the physical properties in layered materials by surface functionalization,we study the thermal and electronic properties ofαʹ-borophene with three different types of gas functional groups(H,F,and Cl)based on first-principles and Boltzmann transport theory.It is found thatαʹ-borophene can be well stabilized by fluorination and chlorination and maintain the semiconductor nature.More interestingly,when hydrogen is replaced with fluorine or chlorine,the lattice thermal conductivity changes from 24.3 to 5.2 or 0.73 W/(m·K)along armchair direction at 300 K,exhibiting a huge reduction by two orders of magnitude.The main reason is the decrease of both phonon group velocities and acoustic phonon relaxation time resulting from the strong phonon mode softening due to the weaken B-B bond strength and heavier atomic mass of fluorine and chlorine.Consequently,the chlorinatedαʹ-borophene exhibits a high thermoelectric figure of merit~2 at 300 K along armchair direction.Our study illustrates the importance of the modulation of transport properties by gas functional groups,which may promote the thermoelectric application of boron-based materials.
