Boron Nanotubes Research Articles

Synthesis of Tungsten Disulfide on B-N-Doped Carbon Nanotubes to Enhance the Electrochemical Performance of Supercapacitors

In this research, boron and nitrogen-doped carbon nanotubes (B-N-CNTs) were synthesized at 900°C using the FCCVD method. Carbon, nitrogen, and boron as source materials were simultaneously introduced using a batch- mode droplet reactor and ferrocene as a catalyst. B-N-CNTs were obtained with diameters ranging from 10 - 50 nm and lengths around 30 – 80 μm. These B-N-CNTs were thoroughly characterized and structurally analyzed. Subsequently, tungsten disulfide (WS2) nanosheets on B-N-CNTs were synthesized using the hydrothermal method to design a composite material and were investigated as electrodes for supercapacitors. The morphological properties of B-N-CNT@WS2 were determined by various analytical techniques such as XRD, FESEM, XPS, and EDS. B-N-CNT@WS2 was investigated as an electrode for supercapacitors in two- and three-electrode cells. In the three-electrode cell, B-N-CNT@WS2 exhibited a specific capacitance of 320 F g−1 at a current density of 0.5 A g−1, while the two-electrode cell showed a capacitance of 41 F g−1. The symmetric supercapacitor at a current density of 5 A g−1 exhibited excellent structural stability by preserving 90% of its specific capacitance after 9000 cycles in the 1 V potential range.

B4C ceramics with increased dislocation density fabricated by reactive spark plasma sintering via carbon nanotubes–boron mixture

Boron carbide with high relative density was prepared in situ using spark plasma sintering. Research on the in-situ reaction of boron and carbon nanotubes reveals that the reaction exhibits high reactivity at 1200 °C. Beyond this temperature, increasing the external pressure was beneficial for particle rearrangement, gas release, and dislocation formation. The result of mechanical properties shows that, the flexural strength and fracture toughness of the boron carbides are 656 ± 9 MPa and 5.0 ± 0.3 MPa m1/2, respectively, when sintered at 1750 °C under continuous pressure ramping conditions–an increase of 64.1% and 46.6% compared to that prepared under constant pressure conditions. Increasing the magnitude of the external stress during the in-situ reaction process can also enhance the particle rearrangement efficiency, inducing the formation of twinning and stacking faults in boron carbide ceramics. High–density twinning and stacking faults dominated the toughening mechanisms of ceramic materials.

On boron nanotubes and their face index

Over the past few decades, significant progress has been made in the development of nanomaterials, including carbon nanotubes, boron nanoclusters, boron nanowires, boron nanotubes and many more. These nanomaterial have revolutionized the twenty first century, finding applications in vital domains such as defense, security, electronics, optical engineering, and medicine. Among these nanomaterials, boron nanomaterials hold great importance in nanotechnology due to their exceptional electrical and mechanical properties. The face index of graph is a metric that plays a crucial role in graph theory, providing valuable insights into the structural properties of a graph. It sheds light on graph’s connectivity and planarity, allowing researchers to analyze and understand its characteristics more effectively. In this article, we calculated the recently introduced face index for three significant classes of boron nanotubes: tri-hexagonal nanotube, tri-angular boron nanotube and boron-α nanotubes.

Degree-based topological indices of boron nanotubes

In the past two decades, boron nanotubes have received significant attention from researchers and scientists due to their wide-ranging applications in electronics, nanodevices, optical engineering, nanobiotechnology, and cosmetics. These nanotubular structures composed of boron present exceptional electrical and mechanical properties, making them highly potential nanomaterials. In this article, we study the molecular structure of significant classes of boron nanotubes, namely, trihexagonal boron nanotubes, triangular boron nanotubes, and boron-α nanotubes. Furthermore, we calculate various topological indices for these nanotubes, including the augmented Zagreb index, Sombor index, reduced Sombor index, sum-connectivity index, and arithmetic–geometric index. These indices hold substantial importance in assessing the physical, chemical, and biological characteristics of boron nanotubes.

Evaluation of deep space exploration risks and mitigations against radiation and microgravity.

Ionizing radiation and microgravity are two considerable health risks encountered during deep space exploration. Both have deleterious effects on the human body. On one hand, weightlessness is known to induce a weakening of the immune system, delayed wound healing and musculoskeletal, cardiovascular, and sensorimotor deconditioning. On the other hand, radiation exposure can lead to long-term health effects such as cancer and cataracts as well as have an adverse effect on the central nervous and cardiovascular systems. Ionizing radiation originates from three main sources in space: galactic cosmic radiation, solar particle events and solar winds. Furthermore, inside the spacecraft and inside certain space habitats on Lunar and Martian surfaces, the crew is exposed to intravehicular radiation, which arises from nuclear reactions between space radiation and matter. Besides the approaches already in use, such as radiation shielding materials (such as aluminium, water or polyethylene), alternative shielding materials (including boron nanotubes, complex hybrids, composite hybrid materials, and regolith) and active shielding (using fields to deflect radiation particles) are being investigated for their abilities to mitigate the effects of ionizing radiation. From a biological point of view, it can be predicted that exposure to ionizing radiation during missions beyond Low Earth Orbit (LEO) will affect the human body in undesirable ways, e.g., increasing the risks of cataracts, cardiovascular and central nervous system diseases, carcinogenesis, as well as accelerated ageing. Therefore, it is necessary to assess the risks related to deep space exploration and to develop mitigation strategies to reduce these risks to a tolerable level. By using biomarkers for radiation sensitivity, space agencies are developing extensive personalised medical examination programmes to determine an astronaut's vulnerability to radiation. Moreover, researchers are developing pharmacological solutions (e.g., radioprotectors and radiomitigators) to proactively or reactively protect astronauts during deep space exploration. Finally, research is necessary to develop more effective countermeasures for use in future human space missions, which can also lead to improvements to medical care on Earth. This review will discuss the risks space travel beyond LEO poses to astronauts, methods to monitor astronauts' health, and possible approaches to mitigate these risks.

Nitrogen, boron and fluorine tri-doped carbon nanotubes on carbon cloth as the electrode materials for supercapacitors

In this study, nitrogen, boron, and fluorine co-doped carbon nanotubes (NBF-CNT) was growth on carbon cloth (CC) through a simple in situ method. The material was used directly as electrodes for supercapacitors and tested for its electrochemical performance. The electrode exhibited an area specific capacitance of 4303.2 mF/cm2 (322.7F/g) at 2 mA/cm2 (0.15 A/g), maintaining 77.4% capacity at 20 mA/cm2. At 10 mA/cm2, the flexible electrode retained 97.8% capacitance after 8000 charge/discharge cycles. Assembled into a symmetrical supercapacitor, the electrodes achieved an area specific capacity of 750.8 mF/cm2 (56.3F/g) at 2 mA/cm2 (0.15 A/g), with energy densities of 104.3 μWh/cm2 (7.8 Wh/kg) and 61.4 μWh/cm2 (4.6 Wh/kg) at power densities of 1000 μW/cm2 (75 W/kg) and 10,000 μW/cm2 (750 W/kg), respectively. The excellent electrochemical performance attibutes two factors: (1) binder-free electrode preparation, mitigating issues related to poor conductivity and low active substance utilization; and (2) the synergistic effect of multi-heteroatom doping in carbon nanotubes, enhancing electrode conductivity and hydrophilicity.

Amorphous FeOOH Anchored on Boron and Nitrogen Codoped Carbon Nanotubes for Fenton-like Oxidation of Sulfamethoxazole

Amorphous iron oxide/hydroxides with structural disorder can be a potential alternative to typical crystalline structures when applied in environmental nanotechnology. In this work, novel amorphous FeOOH quantum dots (QDs) anchored on boron and nitrogen codoped graphene nanotubes (FeOOH@BNG) with different Fe loadings were synthesized and applied in the degradation of common antibiotic pollutant sulfamethoxazole (SMX). The as-fabricated catalysts were characterized by a series of physicochemical and thermal techniques, revealing the highly dispersive FeOOH QDs on the BNG surface. The as-prepared catalyst shows excellent catalytic ability toward SMX degradation via a Fenton-like approach. The excellent activity of the as-prepared FeOOH@BNG catalysts was ascribed to the enhanced textural properties and better exposure of active sites, thanks to the highly dispersive Fe sites on the BNG supports. The optimal catalyst, FeOOH-5@BNG, was further employed for the optimization of key reaction parameters such as catalyst loading, H2O2 dosage, pH, and reaction temperature. Moreover, electron paramagnetic resonance (EPR) and reactive species quenching tests were employed to reveal the responsive reactive oxygen species and the mechanism in the FeOOH@BNG/H2O2 system for SMX degradation. The current study not only opens new insights into the fabrication of amorphous but metallic nanomaterials but also leads to their potential application in environmental remediation.

Fault-tolerance in metric dimension of boron nanotubes lattices.

The concept of resolving set and metric basis has been very successful because of multi-purpose applications both in computer and mathematical sciences. A system in which failure of any single unit, another chain of units not containing the faulty unit can replace the originally used chain is called a fault-tolerant self-stable system. Recent research studies reveal that the problem of finding metric dimension is NP-hard for general graphs and the problem of computing the exact values of fault-tolerant metric dimension seems to be even harder although some bounds can be computed rather easily. In this article, we compute closed formulas for the fault-tolerant metric dimension of lattices of two types of boron nanotubes, namely triangular and alpha boron. These lattices are formed by cutting the tubes vertically. We conclude that both tubes have constant fault tolerance metric dimension 4.

Zagreb connection topological descriptors and structural property of the triangular chain structures

Mathematical chemistry is concerned with the use of mathematics to solve the problems in chemistry. A triangular chain graph is a simple graph composed of a series of triangles. This chain is widely used in the formation of triangular cactus, boron clusters, boron triangular nanotubes, and boron nanotubes. In this paper, the first Zagreb connection index, the first modified Zagreb connection index, and the second Zagreb connection index for triangular chain structures are calculated and derived closed formulas for them. Based on the derived formulas and obtained numerical results, the physicochemical properties of these type of structures can easily be investigated.

Corrosion Behavior of 1D and 2D Polymorphs of Boron Nitride Ceramic.

This study reports a fundamental electrochemical study to understand the corrosion behavior of 1D bulk, free-standing 1D boron nanotube (BNNT) buckypaper and compare it with a sintered 2D hBN nanoplatelet (BNNP) pellet. Tafel analysis indicates that 1D BNNT has superior corrosion resistance with a lower corrosion rate of 0.0026 mils per year (mpy). 2D BNNP, although having similar chemistry to 1D BNNT, resulted in an increased (40 times) corrosion rate of 0.107 mpy. The higher surface area and aspect ratio of BNNT drastically influenced the corrosion kinetics. The scientific outcomes will enable the better design of novel hBN-based corrosion-resistant materials.

Magnetic semiconducting borophenes and their derivatives.

Two semiconducting borophenes with layer-dependent magnetism are predicted based on spin-polarized density functional theory. Both monolayer borophenes are ferromagnetic. One is composed of B3 and B15 triangular motifs, exhibiting bipolar spin polarization and a magnetic moment of 1.00 μB per primitive cell. The other consists of B15 triangular motifs, possessing a Curie temperature of about 437 K and a magnetic moment of 3.00 μB per primitive cell. B atoms located between the triangular motifs are essential for inducing ferromagnetism in monolayer borophenes. However, bilayer borophenes with high-symmetry stacking orders are nonmagnetic. Furthermore, magnetic boron nanotubes and fullerenes could be made of monolayer borophenes. Finally, we propose to fabricate these magnetic semiconducting borophenes from the buckled triangular structure of borophenes via selective electron beam ionization of B atoms by scanning transmission electron microscopy.

Design of Lanthanide Single-Chain Magnets Based on Tubular Segment Clusters

One-dimensional (1D) atomic chains that exhibit large magnetic anisotropy are highly relevant to spintronic applications. Such 1D magnetic systems have usually been produced by atom/molecular assembling on solid surfaces or by coordination polymers. Here, we demonstrate an alternative approach for the formation of a confined ferromagnetic holmium (Ho) atom chain, which is composed of repeating units of the tubular Ho doped boron (B) cluster HoB20. The tubular HoB20 is discovered by the global structural search of a series of small-sized boron clusters doped by a single Ho atom (HoBn, n = 12, 14, 16, 18, 20) using ab initio calculations. Electronic analysis reveals that the individual HoB20 cluster is stabilized by the double σ + π aromaticity. Extending the tubular structure results in a single Ho atom chain being confined inside a boron nanotube, which shows ferromagnetic behaviors and a large magnetic anisotropy of more than 40 meV/atom. Our findings indicate that the magnetic lanthanide chain is a promising candidate for high-density magnetic information storage.

Boron Nanotube Structure Explored by Evolutionary Computations

In this work, we explore the structure of single-wall boron nanotubes with large diameters (about 21 Å) and a broad range of surface densities of atoms. The computations are done using an evolutionary approach combined with a nearest-neighbors model Hamiltonian. For the most stable nanotubes, the number of 5-coordinated boron atoms is about 63% of the total number of atoms forming the nanotubes, whereas about 11% are boron vacancies. For hole densities smaller than about 0.22, the boron nanotubes exhibit randomly distributed hexagonal holes and are more stable than a flat stripe structure and a quasi-flat B36 cluster. For larger hole densities (>0.22), the boron nanotubes resemble porous tubular structures with hole sizes that depend on the surface densities of boron atoms.

High‐Temperature Laser‐Assisted Synthesis of Boron Nanorods, Nanowires, and Bamboo‐Like Nanotubes

A double‐pulsed laser ablation (DPLA) method has been used to synthesize crystalline boron nanorods (BNRs), boron nanowires (BNWs), and bamboo‐like boron nanotubes (BBNTs) from bulk boron (BKB). A q‐switched Nd: YAG laser operating at the first and second harmonic wavelengths with 1064 and 532 nm is used to ablate a solid composite boron target doped with 1% Ni and 1% Co in a tube furnace in flowing argon gas. Boron nanostructures in the form of BNRs, BNWs, and BBNTs are condensed from the hot laser‐induced plasma plume at furnace temperatures of 800, 900, and 1000 °C. The morphology and the chemical and optical nature of the nanostructures are identified from X‐ray diffraction, electron microscopy, energy‐dispersive X‐ray spectroscopy, Raman, UV–vis, and photoluminescence (PL) spectroscopies. The results confirm the crystallinity and phase purity of the boron‐nanomaterials and that they are preferentially grown in the c‐axis direction of α‐boron. The as‐synthesized BNRs, BNWs, and BBNTs are observed to have lengths of 0.2–1.5 μm and widths between 10 and 100 nm, and show respective PL resonance emission peaks at 330, 331, and 333 nm, and the electrical conductivities of 312, 313, and 324 S cm−1 at room temperature which are higher than the electrical conductivity of BKB.

Ultra-stable metallic freestanding multilayer borophene with tunable work function

This study examines the structural stability of 1–3-layer structures of seven typical borophene classes (α, α1, α5, χ3, β12, δ6, and δ3), and the results obtained indicate that α- and α5-borophene exhibits the top two favorable stability in the 1–3-layer series. Accordingly, the structural stabilities, electronic structures, and work functions of 1–5-layer α- and α5-borophene are investigated systematically. The increased binding energies (Eb) with increasing layer number for both α- and α5-borophene demonstrate that their stabilities are enhanced, as confirmed by ab initio molecular dynamics simulations. Remarkably, the interlayer bonding of α-borophene shifts from the isolated covalent dominant B–B bonds (2-layer) to 5- or 6-centered localized bonds with mixed covalent and ionic components (4-/5-layer), leading to the formation of an unprecedented interconnected 2D tubular geometry (α-type boron nanotubes), which significantly enhances the interlayer bonding strength and contributes dominantly to the increasing Eb with increasing layer number. Contrarily, the increased thermodynamic stability for α5-borophene with increasing layer number mainly originates from the increased in-plane bonding interaction. In particular, the highly stable metallic 5-layer α5- (4.54 eV) and α-borophene (5.66 eV) structures with favorable work functions are considered alternative material of graphene and highly attractive anode materials for applications in electronic devices, respectively.

Z-scheme S, B co-doped g-C3N4 nanotube@MnO2 heterojunction with visible-light-responsive for enhanced photodegradation of diclofenac by peroxymonosulfate activation

In this study, the manganese dioxide (MnO2) nanosheets were successfully embedded onto boron and sulfur co-doped g-C3N4 (CNBS) nanotubes to construct the flower-like core–shell CNBS@MnO2 heterojunction with Z-scheme structure for the enhanced photodegradation of diclofenac (DCF) in the presence of peroxymonosulfate (PMS) and 460-nm visible light. The CNBS@MnO2 provides large specific surface area and reduced interfacial resistance for rapid electron transport. Moreover, the redox cycling of Mn species effectively activates PMS to produce sulfate radicals for DCF photodegradation. The PMS-based photodegradation of DCF over CNBS@MnO2 displays the excellentphotodegradation performance after 15 min of irradiation, and the efficiency is highly dependent on initial pH, ion species, and concentrations of PMS and DCF. The CNBS@MnO2 also shows its excellent stability and reusability over ten cycles. Besides, h+, O2●− and SO4●− are the dominantly reactive species for the enhanced degradation of DCF over Z-scheme CNBS@MnO2 heterojunction. The possible reaction mechanism as well as the degradation pathway of DCF over CNBS@MnO2 in the presence of PMS is also proposed. Results clearly highlight the superior photoactivity of Z-scheme CNBS@MnO2 toward micropollutant degradation by PMS activation, which can open an avenue to fabricate the g-C3N4 nanotube@metal oxide structure as an effective activator for water and wastewater purification.

Designing a Four-Ring Tubular Boron Motif through Metal Doping.

Tubular boron clusters represent a class of extremely unusual geometries that can be regarded as a key indicator for the 2D-to-3D boron structural evolution as well as the embryos for boron nanotubes. While a good number of pure boron or metal-doped boron tubular clusters have been reported so far, most of them are two-ring tubular structures, and their higher-ring analogues are very scarce. We report herein the first example of a four-ring tubular boron motif in the cagelike global minimum of Be2B24+. Global-minimum searches of MB24q and M2B24q (M = alkali/alkaline-earth metals; q = 1+, 0, 1-) reveal that the most stable structure of Be2B24+ is a C2v-symmetric cage having a four-ring tubular boron moiety, whereas it is a high-lying isomer for those having a two/three-ring tubular boron motif for all other systems. The B24 framework in Be2B24+ can be viewed as consisting of two two-ring B12 tubular structures linked together at one side of the B6 rings along the high-symmetry axis and two offside B6 rings capped by two Be atoms. The Be2-B24 bonding is best described as Be22+ in an excited triplet state, forming two highly polarized covalent bonds with B24- in a quartet spin state. The unique ability of beryllium to make strong covalent and electrostatic interactions makes the Be2B24+ cluster stable in such an unusual geometry.

Entropy Measures of Some Nanotubes Using Sombor Index

In (QSAR)/(QSPR) studies, topological indices play an essential role, as a molecular descriptor. For measuring the structural information of chemical graphs and complex networks, the graph entropies with topological indices take the help of Shannon’s entropy concept, which now become the information-theoretic quantities. In discrete mathematics, biology, and chemistry, the graph entropy measures play an essential role. In this paper, we study the Boron Nanotube and we compute entropies of these structures by making relation of newly defined degree based topological indices, called Sombor index with the help of the information function, which is the number of vertices of different degrees together with the number of edges among the various vertices. Further, the numerical and graphical comparison are also studied.

Structural Study of Boron Nanotubes by Shigehalli, Kanabur, and Sanskruti Indices Along with their Multiplicative Invariants

Nanotechnology revolutionized the 21st century because of its applications in many important fields like defense and security, electronics, optical engineering, nano devices, nano fabrics, computer, medicine drugs, cosmetics, and nano biotechnology. Boron nanoclusters, boron nanowires, and boron nanotubes have all been developed in the previous 20 years. Keeping in view the sensitivity of boron nanostructures, we have calculated the Shigehalli, Kanabur invariants and their multiplicative versions MSK, MSK_1 and MSK_2 indices of boron tri-hexagonal, boron tri-angular, and boron alpha nanotubes (BANT) are useful in estimating these nanostructures' chemical properties.

Regulation of Electronic Structures to Boost Efficient Nitrogen Fixation: Synergistic Effects between Transition Metals and Boron Nanotubes.

Borophene possesses outstanding physical and chemical properties and thus demonstrates great application potential in catalysis. However, the lack of a controllable strategy for regulating the electronic structures of borophene for efficient catalysis limits the exploration of this material for a "black-box" model. Herein, taking advantage of the synergistic effects between metals and boron nanotubes (BNT), we report a core-shell structure that encapsulates early transition-metal nanowires into BNT (TMs@BNT) to improve the inherent electronic structures of primitive borophene for an efficient electrochemical nitrogen reduction reaction (eNRR). These filled BNT with disconnected π conjugation and vacant boron (B) pz orbitals enable the regulation of electronic states of B atoms in spatial extent and occupancy that has a great effect on the adsorption strength of intermediates. Using first-principles calculations, we demonstrate that the *N2H adsorption energy (ΔE*N2H) is strongly correlated with the intrinsic activity trends and that the variation of ΔE*N2H is attributed to the distribution of 2p states and charge of B atoms. Finally, we utilize the coupling of the d 2p states between B atoms and metals to obtain a quantitative explanation for synergistic effects and conclude that metals with a lower d-band center (εTMd) raise the average 2p state energy (ε̅2p) of B through two-level quantum coupling, which is the physical origin of this interaction. Therefore, two candidates (Mo@BNT and W@BNT) with lower εTMd are screened, benefiting from their high eNRR activity (limiting potentials of -0.75 and -0.77 V, respectively) and high selectivity. This work explores the activity origin, constructs a bridge between electronic structures and activity trends, and paves the way for future eNRR studies.