Boron Nitride Nanoribbons Research Articles

Assembling Si2BN nanoribbons into a 3D porous structure as a universal anode material for both Li- and Na-ion batteries with high performance.

The development of anode materials is critical to the success of sodium ion batteries (SIBs). Because of the size difference between Li and Na, the commercial anode material graphite in Li-ion batteries does not work for Na-ion batteries. Thus, it will be ideal if some universal anode materials could work for both Li- and Na-ion batteries with high performance. Inspired by a recent study on the high performance of a 2D-Si2BN sheet as an anode material for Li-ion batteries, we design a three dimensional (3D) porous structure by using the nanoribbons of a Si2BN sheet as building blocks. Based on the state-of-the-art ab initio calculations, we find that the resulting 3D porous Si2BN structure is stable chemically, dynamically and thermally, exhibiting a high specific capacity of 512.42 (341.61 mA h g-1), a low voltage of 0.27 V (0.15 V), a small volume expansion of 2.5% (2.7%), and a low migration energy barrier of 0.44 eV (0.19 eV) for Li- (Na-) ion batteries. These intriguing features, together with the light mass and rich abundance of Si, B and N, suggest that the 3D porous Si2BN structure is a promising candidate for the anode material of both Li- and Na-ion batteries.

Planar graphene/h-BN/graphene heterostructures for protein stretching and confinement.

Protein stretching and confinement in nanochannels is critical for advancing single-molecule detection techniques. For standard nanochannels integrated with nano-sensors, reducing their cross-section is beneficial for reading highly localized signals with minimal error, but results in increasing difficulty for the initial capture of any chain molecules due to the entropy barrier. Using molecular dynamics simulations, we show that spontaneous protein stretching can be realized by a two-dimensional (2D) heterostructure composed of a hexagonal boron nitride (h-BN) nanoribbon stitched with two graphene (GRA) sheets (i.e., a sandwiched GRA/BN/GRA structure). Due to fast protein diffusion on its flat surface and adsorption potential difference between two 2D materials, this planar nanochannel permits effective capture and elongation of three representative intrinsically disordered proteins including amyloid-β (1-42), polyglutamine (42) and α-synuclein (61-95). Moreover, we found that the extremely narrow h-BN stripe can provide stronger confinement for a longer polyglutamine chain after being stretched. Our approach has the potential to facilitate the bona fide readout of single-molecule protein sequencing techniques.

First-principles study of sensing SO2 adsorption on III–V nitride nanoribbons

The design of efficient, low dimensional sensors is an active topic of research and development. Here, we study the adsorption of SO2 molecules on the edges of III–V nitride nanoribbons to explore their sensing potentials. Zigzag nanoribbons (ZXNNR) and armchair nanoribbons (AXNNR), X = B,Al,Ga, have been investigated. It was noticed that the adsorption of SO2 is mediated via formation of chemical bonds. The calculated adsorption energy varies from -1.09 eV to -4.89 eV for ZXNNR and -0.42 eV to -4.61 eV for AXNNR which ensures the structural stability of considered configurations against thermal excitations. Moreover, for all ZXNNR, a semiconducting to metallic transition has been observed whereas the band gaps in AXNNR are subjected to the adsorption configuration. Further, the selectivity of SO2 with all considered configurations with respect to O2 and N2 is also studied. It is revealed that the selectivity of SO2 with respect to N2 is more suitable as compared to O2. The analysis of recovery time indicates an excellent reversible characteristics in BN nanoribbons irrespective of their edge geometries. GaN nanoribbons could be reversible only for zigzag edges whereas unusually long recovery time in AlN nanoribbons presents them as a disposable sensing material. Present analysis portrays a detailed comparison of zigzag and armchair III–V nanoribbons towards their potential for designing futuristic nano-sensor devices.

Electronic and magnetic properties of Fe-doped narrow zigzag boron nitride nanoribbons

The electronic structures and magnetic properties of single Fe-doped in the different substitutional sites for narrow zigzag boron nitride nanoribbons are studied based on density functional theory. By examining the total energy and formation energy, we predict that doping Fe in the substitutional 4B-site is more favorable than other sites in our calculated narrow zigzag boron nitride nanoribbons. The behavior of doping single Fe in the zigzag boron nitride nanoribbons drives the system to tend to show a spin polarized state, and the induced magnetic moment depends on the substitutional sites. The calculated electronic structures show that Fe-doped narrow zigzag boron nitride nanoribbon becomes a semiconductor with a direct energy gap, while the pristine boron nitride nanoribbon is an insulator with an indirect wide energy gap. The molecular dynamic simulation results predicate that single Fe-doped narrow zigzag boron nitride nanoribbons can exist stably under the realistic environment.

Effect of strain on the mechanical and electronic properties of h-BN nanoribbons with 558 linear defect

Abstract We have applied first principles calculations to investigate the effect of the uniaxial tensile strain on the mechanical and electronic properties of hexagonal zigzag boron nitride nanoribbons (h-ZBNNRs) with embedded 558 linear defect (LD). Our calculations indicate that 558-LD induces a larger decrease in the energy gap if compared to pristine (h-ZBNNRs). In addition, we have shown that the effect of strain displays most efficiency to tune the energy gap than on pristine 558-LD. Also, we have obtained the Young's modulus through two different approaches.

Universal Scaling of Excitons in Quasi One-Dimensional Carbon and Boron Nitride Allotropes

The carbon and the boron nitride analogs of low-dimensional allotropes, including carbon nanotubes, boron nitride nanotubes, graphene nanoribbons, and boron nitride nanoribbons, are promising nanomaterials for the next-generation optoelectronic properties due to their geometry and chirality-dependent semiconductor character. Due to the different intrinsic bonding characters, it presents different pictures for the band gap and exciton binding energies between these two analogs. Here, we present a numerical density functional theory study, with many body effect corrections. By correlating the nanoscale effective screening strength, I reveal a uniform scaling both over the morphology and materials, providing a more insightful and direct understanding for the exciton character in these quasi one-dimension carbon and boron nitride materials by both the geometry determination and dielectric screening.

Tuning the Electronic and Magnetic Properties of Graphene Flake Embedded in Boron Nitride Nanoribbons with Transverse Electric Fields: First-Principles Calculations.

The electronic and magnetic properties of h-BN nanoribbions embedded with graphene nanoflakes (CBNNRs) are systematically studied by ab initio calculations. The CBNNRs with zigzag or armchair edges are all bipolar magnetic semiconductors (BMSs). The band gaps of zigzag CBNNRs (zCBNNRs) change linearly with the transverse electric field (E-field) for the first-order Stark effect, whereas for the armchair CBNNRs (aCBNNRs), the band gaps vary quadratically with the E-field for the second-order Stark effect. For zCBNNRs and aCBNNRs, they could transform from BMS to spin gapless semiconductor (SGS), metal, and half-metal (HM) under different transverse E-fields. The CBNNRs may transform into a semiconductor or HM, under the same E-fields, depending on the position of graphene flakes. The CBNNRs introduce local magnetic moment at carbon atoms, and the magnetic moment is determined by the size of the graphene flakes. These observations open the door to applications of CBNNRs in spintronic devices.

Theoretical investigation on the structures, electronic and magnetic properties of new 2D/1D composite nanosystems by adsorbing superhalogen MnCl3 on the BN monolayer/nanoribbons

Hexagonal boron nitride (h-BN), an inorganic analogue of graphene, possesses the remarkable physical and chemical properties and can be viewed as the powerful building block to construct novel composite nanomaterials. In this study, based on the first-principles calculations, we design a new class of hybrid nanosystems by depositing superhalogen MnCl3 on the surface of low-dimensional BN monolayer or nanoribbons (BNML/BNNRs). The large adsorption energies indicate that the MnCl3 can be stably adsorbed on the surface of the BN materials. Regardless of dimension, chirality, ribbon width as well as the adsorption site and coverage of MnCl3, adsorbing MnCl3 can endow these hybrid BN nanomaterials with a large magnetic moment and significantly reduce the robust wide band gap of BN materials to the range of 0.098–0.948 eV. Overall, these new MnCl3–BN composite nanostructures can display the large magnetism and an appropriate band gap, which is very promising to make them an application in the field of multifunctional nanodevices and magnetic materials in the near future.

Location-dependent Stone-Wales defect in C/BN heteronanotube: A density functional theory approach

Ab initio pseudopotential density functional calculations of location-dependent Stone-Wales (SW) defect are performed to investigate the electronic and optical characteristics of (10,0) zigzag-edged hybrid Carbone/Boron-Nitride (C/BN) heteronanotubes which recently have been proposed to exhibit promising properties. These heteronanotubes are circumferentially formed from two curled carbon and boron nitride nanoribbons. Here, we report a systematic study on the effective role of SW defect located at different radial positions along the heteronanotube. The calculated band gap of the structures and also SW formation energies reveal that the defects preferentially localize at the very interface of the BN and graphene segments. Moreover, the critical importance of the boundary-oriented SW defect (either BN or graphene edges) is comprehensively studied using optical absorption spectra, electron charge density 2D maps, and bonding configurations of occupied/unoccupied π orbitals corresponding to the B–C/C–N bonds. Our results provide new insights into the band gap engineering of C/BN heterostructures which are the potential candidate for the future optoelectronic applications.

Flexoelectric Effects in Corrugated Boron Nitride Nanoribbons

Hexagonal boron nitride (h-BN) monolayer is an isostructural analogue to graphene and promising dielectric. Inspired by recent experimental reports, we focus on suspended and corrugated boron nitride nanoribbons (BNRs) as model systems, and report an intriguing flexoelectric polar effect using a series of ab initio-based density functional theory and tight binding calculations. Our results decode various synergies of the complex flexoelectrical properties including the role of corrugation height, structural deformation, and orbital mixing in corrugated BNRs. We demonstrate structural deformation of BNRs significantly contribute to the magnitude of electric dipole moment and bandgap closing, converting the insulating BNRs to semiconductors. This important finding, combined with the fundamental insights into the nature of electromechanical coupling, provides key hypotheses for design and modulation of novel nanoelectronic and nanophotonic devices.

Spin transport properties in Fe-doped graphene/hexagonal boron-nitride nanoribbons heterostructures

By combining non-equilibrium Green's function (NEGF) with density functional theory (DFT), we systematically study the spin-related transport properties of the heterostructures composed of graphene and hexagonal boron-nitride (h-BN) when the metal Fe is doped different positions of the heterostructures interface. The results show that the heterostructures exhibit obvious spin-filtering effect (SFE) and negative differential resistance (NDR) due to the different absorbing positions of the metal Fe. And the spin filtering ratio can reach more than 90% in a specific bias voltage range. Moreover, spin-rectifying behaviors are detected in the heterostructures. Whether it is for the design of multifunctional devices or the synthesis of spintronic devices, these findings will have some reference value.

Boron Nitride Aerogels with Super‐Flexibility Ranging from Liquid Nitrogen Temperature to 1000 °C

AbstractAerogels with extraordinary mechanical properties attract a lot of interest for their wide spread applications. However, the required flexibility is yet to be satisfied, especially under extreme conditions. Herein, a boron nitride nanoribbon aerogel with excellent temperature‐invariant super‐flexibility is developed by high temperature amination of a melamine diborate precursor formed by hydrogen bonding assembly. The unique structure of the aerogel provides it with outstanding compressing/bending/twisting elasticity, cutting resistance, and recoverable properties. Furthermore, the excellent mechanical super‐flexibility is maintained over a wide temperature range, from liquid nitrogen temperature (−196 °C) to higher than 1000 °C, which extends their possible applications to harsh environments.

Reactivity of Atomically Functionalized C-Doped Boron Nitride Nanoribbons and Their Interaction with Organosulfur Compounds.

The electronic and reactivity properties of carbon doped (C-doped) boron nitride nanoribbons (BNNRs) as a function of the carbon concentration were investigated in the framework of the density functional theory within the generalized gradient approximation. We found that the main routes to stabilize energetically the C-doped BNNRs involve substituting boron atoms near the edges. However, the effect of doping on the electronic properties depends of the sublattice where the C atoms are located; for instance, negative doping (partial occupations of electronic states) is found replacing B atoms, whereas positive doping (partial inoccupation of electronic states) is found when replacing N atoms with respect to the pristine BNNRs. Independently of the even or odd number of dopants of the C-doped BNNRs studied in this work, the solutions of the Kohn Sham equations suggest that the most stable solution is the magnetic one. The reactivity of the C-doped BNNRs is inferred from results of the dual descriptor, and it turns out that the main electrophilic sites are located near the dopants along the C-doped BNNRs. The reactivity of these nanostructures is tested by calculating the interaction energy between undesirable organosulfur compounds present in oil fuels on the C-doped BNNRs, finding that organosulfur compounds prefer to interact over nanosurfaces with dopants substituted on the B sublattice of the C-doped BNNRs. Most importantly, the selective C doping on the BNNRs offers the opportunity to tune the properties of the BNNRs to fit novel technological applications.

Magnetic switches via electric field in BN nanoribbons

The realization of strong magnetoelectric (ME) coupling for efficiently controlling of magnetism is urgently needed but still a significant challenge. Based on first-principle calculations and effective Hubbard models, we demonstrated that the polar charges and locality of edge states in hexagonal BN nanoribbons (BNNRs) play key roles in the behavior of edge magnetism M. By applying a transverse electric field, the magnetism in both zigzag and armchair edges can be regulated sufficiently. In particular, the magnetic on/off switches can be realized in armchair edges, it is robust against various edge decorations including hydrogenation, fluoridation and hydroxylation. Furthermore, uniaxial tensile strains can also produce significant magnetic modulation in Z-BNNRs, which stem from the piezoelectricity. All these suggest that h-BNNRs are ideal platforms for ME coupling researching and promising candidates for functional spintronics application.

Neurotransmitter-Functionalized Boron Nitride Nanoribbons as Biological Cargo Carriers: Analysis by Density Functional Theory

The structural and electronic properties of boron nitride nanoribbons (BNNRs) adsorbed with two neurotransmitters, dopamine (DA) and adrenaline (AD), have been systematically investigated using ele...

Thermal spin transport properties in a hybrid structure of single-walled carbon nanotubes and zigzag-edge boron nitride nanoribbons

The spin caloritronics device, because of the characteristics of spintronics and thermoelectronics, plays an important role in human sustainable development. A lot of spin caloritronic devices based carbon materials (such as graphene nanoribbons, carbon nanotubes) have been reported. However, there are few studies of the thermal spin transport properties in a hybrid structure of single-walled carbon nanotubes and zigzag-edge BN nanoribbons, and the thermal spin transport mechanism of this structure is still unclear. In this paper, using the nonequilibrium Green’s function (NEGF) combined with the first principle calculations, the electronic structures and the thermal spin transport properties of the zigzag edge BN nanoribbons functionalized single-walled carbon nanotubes are studied. It is shown that the ZBNRs-N-(6, 6)SWCNT is a half-metal, while the <i>n</i>ZBNRs-N-(6, 6)SWCNT are magnetic metals (<i>n</i> = 2−8), and the <i>n</i>ZBNRs-B-(6, 6)SWCNT are bipolar magnetic semiconductors (<i>n</i> = 1−8). The 4ZBNRs-N-(4, 4)SWCNT and 4ZBNRs-B-(4, 4)SWCNT are half-metals, while the 4ZBNRs-B-(<i>m</i>, <i>m</i>)SWCNT (<i>m</i> = 5−9)are magnetic metals, and the 4ZBNRs-N-(<i>m</i>, <i>m</i>)SWCNT (<i>m</i> = 5−9) are bipolar magnetic semiconductors. Then, some novel spin caloritronicdevices are designed based on <i>n</i>ZBNRs-N-(6, 6)SWCNT and <i>n</i>ZBNRs-B-(6, 6)SWCNT (<i>n</i> = 1, 8). For the ZBNRs-B-(6, 6)SWCNT, when the temperature of the left electrode is increased above a critical value, the thermal spin-up current then increases remarkably from zero. Meanwhile the thermal spin-down current remains approximately equal to zero in the entire temperature region, thus indicating the formation of a thermal spin filter. For the 8ZBNRs-N-(6, 6)SWCNT and <i>n</i>ZBNRs-B-(6, 6)SWCNT (<i>n</i> = 1, 8), when a temperature gradient is produced between two electrodes, the spin-up and spin-down currents are driven in the opposite directions, which indicates that the spin-dependent Seebeck effect (SDSE) appears. In order to obtain the fundamental mechanism of thermal spin filter effect and SDSE, the Landauer-Büttiker formalism is adopted. It is found that the currents (<i>I</i><sub>up</sub> and <i>I</i><sub>dn</sub>) mainly depend on two factors: 1)the transport coefficient; 2) the difference between the Fermi-Dirac distributions of the left and right electrode. Additionally, the electron current <i>I</i><sub>e</sub> and the hole current <i>I</i><sub>h</sub> will be generated when a temperature gradient is produced between the left and right lead. Furthermore, the <i>I</i><sub>up</sub> and <i>I</i><sub>dn</sub> have the opposite directions for the spin up transmission peaksbelow the Fermi level while they have the opposite directions for the spin down transmission peaks above the Fermi level in the transmission spectrum, which demonstrates the presence of the SDSE in the 8ZBNRs-B-(6, 6)SWCNT and <i>n</i>ZBNRs-N-(6, 6)SWCNT (<i>n</i> = 1, 8). Finally, the results indicate that <i>n</i>ZBNR-N-(<i>m</i>, <i>m</i>)SWCNT and <i>n</i>ZBNR-B-(<i>m</i>, <i>m</i>)SWCNT can have potential applications in thermospin electronic devices.

The role of sp2 and sp3 hybridized bonds on the structural, mechanical, and electronic properties in a hard BN framework.

A first-principles approach is used to systematically investigate the role of sp2 and sp3 hybridized bonds on the structural, mechanical, and electronic properties in a new BN phase (denoted Hex-(BN)12). Hex-(BN)12 has the same number of sp2 and sp3 hybridized atoms. The calculated cohesion energy, phonon frequencies, and elastic constants unambiguously confirm the structural stability of this compound. Due to the different types of hybridization and B–N covalent bonds with ionic characteristics, Hex-(BN)12 has unequal bond lengths and bond angles in these hybrid orbitals. These cause the relative energetic stability to be slightly lower than c-BN and w-BN. The hardness of Hex-(BN)12 is estimated to range from 33 to 40 GPa. The bond-breaking order under stress is sp3–sp3, sp2–sp3, and sp2–sp2. DFT calculations with the gradient approximation (GGA) and HSE06 functional indicate the electronic structure contains an indirect band gap at 3.21 and 4.42 eV, respectively. The electronic states in the region near the Fermi level primarily arise from the 2p orbitals in sp2-hybridized atoms. In general, sp3 bonded B and N atoms guarantee higher mechanical properties, and sp2 bonded atoms ensure ductility and even conductivity, although all changes vary with spatial structure. Hex-(BN)12 can be obtained from multilayer yne-BN, and BN nanosheets, nanotubes and nanoribbons under pressure.

Magneto-EELS of armchair boronitrene nanoribbons.

The evolution of the electron energy loss spectrum (EELS) of ultranarrow armchair boron nitride nanoribbons (aBNNRs) during low and high photon energy transfers has been studied theoretically when a magnetic field and temperature gradient are applied. In order to achieve this goal, the widely used linear response theory within the Green’s function theory was employed. Here, using the EELS we show that σ ↦ σ* or π ↦ π* and σ ↦ π* or π ↦ σ* excitations corresponding to the intraband and interband transitions, respectively, can be tuned by ribbon width, magnetic field, wave vector transfer, and temperature. A comparison with experimental studies reveals that for realistic ribbon widths, i.e. 10–100 nm, both excitations are weak. However, we observe that only transitions between the same states, i.e. σ ↦ σ* or π ↦ π* can be controlled with a magnetic field due to the localized highest occupied and lowest unoccupied states at low-energy regions and different states are not influenced when the magnetic field is applied. Interestingly, the detailed shape of the magneto-EELS of the 7-aBNNR indicates a direct-to-indirect band gap transition when the wave vector transfer is perpendicular to the 7-aBNNR plane. Finally, we discover that there is an anomalous behavior for the temperature dependence of the magneto-EELS in general. The present work brings forward the understanding of the magneto-EELS of ultranarrow aBNNRs under different environmental conditions for logic applications in nanoplasmonics.

A cross-interface model for thermal transport across the interface between overlapped nanoribbons.

The application of low-dimensional materials for heat dissipation requires a comprehensive understanding of thermal transport at cross-interfaces, which widely exist in various composite materials and electronic devices. In this work, an analytical model is proposed, named as the cross-interface model (CIM), to accurately reveal the essential mechanism of the two-dimensional thermal transport at cross-interfaces. The applicability of CIM is validated through a comparison of the analytical results with molecular dynamics simulations for a typical cross-interface between two overlapped boron nitride nanoribbons. Besides, it is found that both the thermal resistances and the factor, η, has an important influence on the thermal transport. These investigations would deepen the understanding of the thermal transport at cross-interfaces and also facilitate the application of low-dimensional materials in thermal management.

Porous boron nitride nanoribbons with large width as superior adsorbents for rapid removal of cadmium and copper ions from water

Porous boron nitride nanoribbons with large width and their possible mechanism for the removal of heavy metals.