Metal Boron Research Articles

Study of hybrid nanoscatterer for enhancing light efficiency of quantum dot-converted light-emitting diodes

Optical scatterer additives play a critical role in enhancing the light conversion efficiency and uniformity of quantum dot-converted light-emitting diodes (Qc-LEDs). This study investigates the impact of optical characteristics and morphology of nanoscatterer on the light conversion and extraction efficiency of Qc-LEDs. Various metal oxides and boron nitride nanoparticles and nanoplates with different diffraction index were selected to carry out the study. Finite-Difference Time-Domain (FDTD) simulation was employed to evaluate the scattering effect of various nanosphere and nanoplate scatterers on the optical performance of the Qc-LEDs. The simulation results revealed that the hybrid nanoscatterer integrates the forward-scattering from the nanosphere and backward-scattering of blue light from the nanoplate. Spectral analysis was conducted to examine the optical performance of Qc-LEDs with varying combinations and concentrations of nanoscatterers. TiO2 nanoparticles and Al2O3 nanoplates were found to be the best combination for maximal light conversion and extraction efficiency within Qc-LEDs. The results indicate an optimal light efficiency is obtained with the optimal ratio of 1:2:2 for quantum dots, TiO2 nanoparticles, and Al2O3 nanoplates. These findings reveal the relationship between optical properties, morphology, and light conversion efficiency in Qc-LEDs, highlighting the advantages of the hybrid nanoscatterers for improving optical performance of Qc-LEDs.

Governing of the piezoelectric effect by external fields and strains

Piezoelectricity in quantum rare-earth metallic boron oxides with the coupling between magnetic, electric and elastic subsystem is studied theoretically. It is proved that the change of piezoelectric modules of the considered crystals are proportional to components of the quadrupole susceptibility, which determines the external magnetic and electric fields, strain and temperature dependences of that change. We show why holmium compounds manifest the strongest renormalization among other rare-earth ions in this family of crystals. The reason is in the structure of the low energy term of the electron configuration, depending on spins and orbital moments of 4f electrons.

Bilayer Borophenes Exhibit Silicon‐Like Bandgap and Carrier Mobilities

AbstractBorophene, a boron analogue of graphene, is typically metallic, while all bulk boron phases are insulating. Here, we predict by first‐principles calculations that recently synthesized bilayer borophene, being suggested to be composed of two stacked v1/12 sheets, is a semiconductor with a bandgap of 1.13 eV, almost the same as that of silicon. It is shown that the stacking mode between two boron sheets as well as the density and pattern of the interlayer boron‐boron (B─B) bonds are the key factors for opening the bandgap in the otherwise metallic boron sheet. Moreover, the bilayer borophene exhibits electron mobility of 878.6 cm2 V−1 s−1 and a significantly higher optical absorption coefficient in the visible region than silicon. These excellent electronic and optical properties hosted in a two atom‐thick space, together with high thermal and mechanical stability, position the bilayer borophene as a promising nanomaterial for maintaining the miniaturization of electronics.

Metalloborospherene Analogs to Metallofullerene

Boron, the neighbor element to carbon in the periodic table, is characterized by unique electron deficiency that fosters multicenter delocalized bonding, contributing to its diverse chemistry. Unlike carbon cages (fullerenes), which preserve their structural integrity under endohedral or exohedral doping, larger boron cages (borospherenes) exhibit diverse structural configurations. These configurations can differ from those of pure boron cages and are stabilized by various metals through unique metal–boron bonding, resulting in a variety of metalloborospherenes. Due to boron’s electron deficiency, metalloborospherenes exhibit fascinating chemical bonding patterns that vary with cluster size and the type of metal dopants. This review paper highlights recent advancements in metalloborospherene research, drawing comparisons with metallofullerenes, and focuses on the use of transition metals, lanthanides, and actinides as dopants across various cage dimensions.

First-principles study of CH2O, CH4, Cl2, HCN, and CNCl gas adsorption behavior by h-BN boron site modification

The potential application of metallic boron bit-doped hexagonal boron nitride monolayers (h-BN@M, M = Fe, Sn, Cu, Zn) as materials for the detection of hazardous gases (CH2O, CH4, Cl2, HCN, and CNCl) has been investigated based on the first nature principle. h-BN@Fe exhibits chemisorptive properties for the adsorption of HCN and CNCl and h-BN@Sn exhibits chemisorption and appropriate humidity resistance. The recovery time of HCN on the h-BN@Fe surface and CNCl on the h-BN@Sn surface was significantly shortened under the 392 K ultraviolet light attempt frequency. In the presence of an applied electric field, HCN and CNCl on the h-BN@Fe surface and CNCl on the h-BN@Sn surface showed adjustable recovery times. This suggests that it is possible to design gas sensing devices with good adsorption characteristics on metallic boron bit-doped hexagonal boron nitride monolayers. In the future, the performance of these materials for the detection of hazardous gases will be improved by changing their structure and composition.

High entropy (HfTiZrVNb)B2 ceramic particulate reinforced Al matrix composites: Synthesis, mechanical, microstructural and thermal characterization

This study aims to introduce a novel type of particulate reinforced Al matrix composite. High entropy (HfTiZrVNb)B2 ceramic particulate reinforced Al matrix composites were produced via a combined process of different powder metallurgy methods. Firstly, boride compounds (HfB2, TiB2, ZrB2, VB2, NbB2) were synthesized in the laboratory scale using the related metal oxide, boron oxide, and magnesium by mechanochemical synthesis (MCS) and leaching processes under optimum conditions. Secondly, the synthesized and purified boride powders were mixed in equimolar ratios using a planetary ball mill for 72 h, and they were sintered at 2000 °C under 30 MPa via spark plasma sintering (SPS). Thirdly, equimolar high entropy (HfTiZrVNb)B2 bulks were crushed, converted into powder forms, and added into Al powders at different amounts as 1, 2, 5, 10, and 15 wt %. Lastly, these powder blends were mechanically alloyed in a vibratory ball mill for 6 h, cold pressed and pressureless sintered at 630 °C for 2 h. For characterization techniques, X-ray diffractometry (XRD), thermal analysis, scanning electron microscopy/energy dispersive spectrometry (SEM/EDS), density measurements using pycnometer and Archimedes' methods, microhardness and dry sliding wear tests were conducted on the sintered composites. The highest hardness (∼1.5 GPa) and the lowest wear rate (∼0.0012 mm3/Nm) were obtained in the Al-15 wt % (HfTiZrVNb)B2 sample.

Low-temperature fabrication of boron-doped amorphous silicon passivating contact as a local selective emitter for high-efficiency n-type TOPCon solar cells

Tunnel oxide passivating contact (TOPCon) solar cells (SCs) currently dominate the photovoltaic industry but grapple with efficiency challenges. A primary concern is the direct contact between front-sided metal electrodes and boron emitters, resulting in substantial carrier recombination losses and limiting further efficiency improvements. Here, we introduce a low-temperature approach to deposit a local boron-doped amorphous silicon [a-Si:H(p)] between front-sided metal electrodes and boron emitters. This method, avoiding issues associated with high-temperature processes, demonstrates excellent passivation and contact properties, featuring the lowest contact resistivity (< 1 mΩ·cm2) and a low saturation current density (< 400 fA/cm2). The outstanding passivation and contact properties remain robust even with variations in diborane flow rates during a-Si:H(p) fabrication, annealing temperatures, and sheet resistances of boron emitters. We elucidate the factors contributing to the enhanced passivation observed in boron emitters with a-Si:H(p) through a combination of simulations and experiments. The a-Si:H(p) layer between boron emitters and metal electrodes acts as a protective barrier, preventing the diffusion of metal atoms and suppressing carrier recombination. A heterojunction is formed between a-Si:H(p) and the boron emitter, facilitating electric-field passivation. Consequently, the TOPCon SCs incorporating a-Si:H(p) achieve an efficiency of 24.50%, surpassing their counterparts without a-Si:H(p) (23.11%). This work utilizes low-temperature technology to achieve fully passivated contact, providing insights for the development of high-efficiency TOPCon SCs.

Combustion Behavior of Fuel Droplets with Metallic, Non-Metallic and Organo-Metallic Boron Additives

ABSTRACT There is considerable interest in the utilization of fuels derived from boron materials, with their high calorific value, in various applications ranging from propellants to pyrotechnics. Conversely, their impact on the combustion behavior of conventional hydrocarbon fuels remains largely unclear. In this study, ignition, combustion, micro-explosion and simultaneous atomization behaviors of gasoline-based alternative fuels containing metallic (28–35 µm MgB2), nonmetallic (1 µm amorphous boron, 10 µm AlB12 with 86–88% and 95–97% purity) and organo-metallic boron derivatives (triethyl borate (TEB) containing C2H5 groups and trimethyl borate (TMB) containing CH3 groups) were investigated. The experiments were carried out at droplet scale and recorded using a high-speed camera and a thermal camera. The findings revealed a systematic reduction in ignition delay for each gasoline fuel enriched with boron derivatives. 2.5%AlB12/G and pure TMB droplets were the fastest extincting fuel droplets (0.9678 s and 1.245 s, respectively). The highest maximum flame temperature was recorded as 626 K and 610 K for pure TMB and 80%TEB/G, respectively. Droplet diameter regression analyses showed that the diameters of fuel droplets containing predominantly metallic and nonmetallic boron derivatives decreased in accordance with the d 2 -law. This study demonstrated that cost-effective and easily producible amorphous boron and organometallic boron derivatives are promising energy carriers for hydrocarbon fuels.

Two-Dimensional Transition Metal Boron Cluster Compounds (MBnenes) with Strain-Independent Room-Temperature Magnetism.

Two-dimensional (2D) metal borides (MBenes) with unique electronic structures and physicochemical properties hold great promise for various applications. Given the abundance of boron clusters, we proposed employing them as structural motifs to design 2D transition metal boron cluster compounds (MBnenes), an extension of MBenes. Herein, we have designed three stable MBnenes (M4(B12)2, M = Mn, Fe, Co) based on B12 clusters and investigated their electronic and magnetic properties using first-principles calculations. Mn4(B12)2 and Co4(B12)2 are semiconductors, while Fe4(B12)2 exhibits metallic behavior. The unique structure in MBnenes allows the coexistence of direct exchange interactions between adjacent metal atoms and indirect exchange interactions mediated by the clusters, endowing them with a Néel temperature (TN) up to 772 K. Moreover, both Mn4(B12)2 and Fe4(B12)2 showcase strain-independent room-temperature magnetism, making them potential candidates for spintronics applications. The MBnenes family provides a fresh avenue for the design of 2D materials featuring unique structures and excellent physicochemical properties.

A mini review on two dimensional (2D) materials for energy storage applications

The discovery of new class of nanomaterials referred to as two-dimensional (2D) materials create extensive attention due to their unique features such as very small size, high anisotropy, high strength, high young’s modulus and excellent flexibility. The addition of numerous 2D materials, including black phosphorous, transition metal oxides, MXene materials, boron nitrides and others, were discovered following by the graphene. The most common 2D material are widely used in energy storage devices due to its large specific surface area, large lateral size and superior performance and adaptability. Due to the environmental, conductive, and catalytic uses, MXene materials are also attaining great attention. The synthesis and applications of two-dimensional materials like graphene and MXene, are the primary focus of this review paper.

Effect of transition metals co-dopant on eliminating boron and phosphorous impurities from silicon

In this work, we report the results of the systematic studies of the interactions between boron and phosphorous impurities in silicon matrix and transitional metals (TM) co-dopants: iron, cobalt, and nickel. Calculations results demonstrate the favorability of the stable pairs of substitutional boron and phosphorous defects. Calculated energies of the formation of substitutional and interstitial TM defects explain the high solubility and mobility of this kind of impurity. The simulations also reveal reciprocal affinity between B, P, and TM impurities that leads to the migration of metal atoms toward boron and phosphorous defects. Redistribution of the charge density caused by the presence of TM in the neighboring position leads to a significant decrease in the energy cost for the migration of B and P substitutional impurities to the interstitial void.

Editorial—Special Issue on Functional Surfaces: Manufacturing, Measuring, and Performance

Abstract Surface treatments are intimately linked to mitigating or avoiding failures due to fatigue, corrosion, and wear. In addition, the advent of new challenges in the industry—mainly associated with an enhanced sustainability of industrial processes—makes surface engineering a critical scientific field. Controlling the superficial and subsuperficial aspects of integrity is crucial in keeping mechanical components at the allowed level of energy consumption. Hence, designing functional surfaces means examining more than just the operating surface processes to get an overview of the whole chain of inputs/outputs. It has been an absolute pleasure to be guest editors for ASTM International’s Materials Performance and Characterization Special Issue on Functional Surfaces: Manufacturing, Measuring, and Performance. The call for papers was based on the investigations presented at Symposium T of XX B-MRS Meeting in Iguassu Falls, Brazil, from September 25–29, 2022. In the symposium, four invited lectures, 12 oral presentations, and 11 posters were presented to the conference attendees. From this total, seven manuscripts were revised for the Special Issue. The other two papers are from the same meeting after we called through other symposia on surface processing. The papers herein cover relevant topics on surface engineering. The first two focus on plasma technology applied to structural steel to increase its tribological and corrosion behaviors and to a polymer for a microfluidic application. Furthermore, we can find an investigation into diamond-like carbon coatings applied to the automotive industry. Additive manufacturing is another presented technology, and the effect of laser on additive manufacturing was investigated in a fourth manuscript. Another case is the plasma transferred arc, which investigated the incorporation of intermetallic for exposure at high temperatures. Next, we have a pair of two papers using double-pack cementation, incorporating the effect of metallic elements or boron into their performances. Following that is one paper about the high-velocity oxygen fuel process using metallic alloys, and the final paper is about developing the gas tungsten arc welding technique through flux-core-double-wire, enhancing the wear performance through hard carbides. We sincerely thank the authors and reviewers for their hard work and dedication. We wholeheartedly thank the ASTM staff for dealing with the issues of publishing an outstanding journal. We hope that all papers contribute to the state-of-art of the surface engineering field. Professor Giuseppe Pintaude Universidade Tecnológica Federal do Paraná, Curitiba, Brazil Professor Ana Sofia C. M. d’Oliveira Universidade Federal do Paraná, Curitiba, Brazil Professor André P. Tschiptschin Universidade de São Paulo, São Paulo, Brazil Dr. Filipe Fernandes Instituto Superior de Engenharia do Porto (ISEP), Porto, Portugal

Development of a green catalytic route to light olefins by Fischer-Tropsch synthesis with renewable hydrogen: Investigation of boron doped activated carbon supported iron catalyst

Hydrogen economy will open the door to a low carbon future and Fischer–Tropsch Synthesis (FTS) is one of the sustainable and carbon neutral catalytic route to a variety of products such as light olefins, kerosene, gasoline etc. when CO and H2 come from catalytic reduction of air captured CO2 and water electrolysis using the surplus renewable electricity, respectively. The aim of this study is to discover the new catalysts towards the sustainable C2–C4 olefins. Activated carbon (AC) supported zinc titanates w/o boron doping have been prepared and investigated for olefins via FTS. AC was deliberately chosen due to its surface structure more prone to modification since boron (B) is known to increase the interaction between surface metal atoms and defects. The B-doped AC supported iron catalyst showed comparable catalytic stability as the original AC supported one. However, an only increase in light olefin selectivity was observed with B-doping treated at 800 C. On the other side, a higher CH4 and paraffin but lower olefin and C5+ selectivity was obtained at the lower thermal treatments. B-doping appeared to improve the catalytic stability but not to bring the expected catalytic activity and selectivity. The strong interaction between the surface metal sites and boron is believed to cause the restricted formation of active sites that leads less CO conversions.

The Effect of Nano and Metallic Boron Spray on some Growth Traits of Sweet Corn under Water Stress Conditions

Under conditions of water stress, a field experiment was carried out to investigate the effect of spraying with nano and metal boron on certain vegetative development parameters of the sweet crop (Zea mays L. Var saccharata) in the fall seasons of 2021 and 2022. The experiment was designed to evaluate the effect of spraying with nano and metal boron. A split-plot R.C.B.D. with three replications was used to design the experiment. W1, W2, and W3 represented 40%, 60%, and 80% water depletion in the major plots. The sub-plots were treated with two concentrations of boron nano particles (5 and 10 mg L-1) designated N1 and N2, two concentrations of metal boron (20 and 40 mg L-1) denoted M1 and M2, and a control treatment of spraying distilled water only. The number of days from planting to 75% tasseling, plant height, leaf number, leaf area, leaf area index, plant dry weight, and crop growth rate for both seasons did not differ between 40% and 60% water stress. 80% water stress decreased all trait averages. Nano and metallic boron spraying significantly affected most features. Spraying with 5 mg L-1 nano-boron concentration reduced the number of days from planting to 75% tasseling by 46.89 and 47.11 days, as well as plant height (141.36 and 142.10 cm), leaf number (13.40 and 13.51 leaves plant-1), plant dry weight (165.80 and 165.93 g plant-1), and crop growth rate (3.53 and 3.51 g m2 day-1 ) for both seasons. However, spraying with 10 mg L-1 nano-boron concentration produced the largest average leaf area (4507.90 and 4530.80 cm2 plant-1) and leaf area index (2.40 and 2.41, respectively) compared to the control treatment for both seasons. For both seasons, Water stress and nano/mineral boron spraying influenced plant height, leaf area, leaf area index, and dry weight. In cases of restricted irrigation water, we propose watering when the available water is 60% drained and spraying with nano boron at 5 mg L-1 to improve the plant’s performance in most of the sweet corn crop’s development features.

2-Dimensional Materials for Performance Enhancement of Surface Plasmon Resonance Biosensor: Review Paper

Surface plasmon resonance (SPR)--based biosensors compete and excel among optical biosensors because of exceptional features such as high sensitivity, label-free, and real-time measurement, allowing the observation of molecular binding kinetics. In SPR biosensors and other biosensor techniques, surface functionalization and bioreceptor attachment are effective strategies to improve sensor performance. The application of an appropriate immobilization matrix for the bioreceptor is an essential step in maximizing the absorption of the bioreceptor on the sensor surface, thereby improving a specific target-sensor interaction. Furthermore, the materials should provide excellent optical properties to enhance the response signal. The high surface-to-volume ratio and high optical absorption of 2D materials qualify these requirements, thus promising advancements for SPR biosensors. This article reviews the recent SPR biosensor study with the use of the 2D materials family to improve the sensor performance, including graphene, transition metal dichalcogenides (TMDCs), MXene, black phosphorus (BP), perovskite, and boron nitride (BN). The materials properties and enhancement mechanisms of different 2D materials are discussed comprehensively. This review was expected to provide a future perspective and design approach for 2D materials-based SPR biosensors.

ROLE OF NANO AND METALLIC BORON FOLIAR NUTRITION ON WATER STRESS REDUCING IN SWEET CORN YIELD AND ITS COMPONENTS

A field experiment was conducted in the experimental field of the Crop Sciences Department at the College of Agricultural Engineering Sciences - University of Baghdad during fall seasons of 2021 and 2022. The aim of this study was to investigate the role of nano and metallic boron foliar nutrition on yield, components, water use efficiency, and water consumption under water stress for sweet corn (Zea mays L.). Randomized Complete Block Design was used within split -plot arrangement with three replicates, where the main plots included three levels of water stress (irrigation at 40, 60, and 80% of available water) coded as W1, W2, and W3, respectively. The nano and metallic boron spray concentrations represented 5, 10, 20, and 40 mg L-1 coded as N1, N2, M1, and M2, respectively. Results showed that nano and metallic boron concentrations significantly affected all the studied traits. The concentration of 5 mg L-1 of nano boron N1 significantly exceeded other concentrations under study in increasing ear length, number of rows per ear, number of grains per row, and weight of 500 grains, which positively reflected on improving grain yield of 5.93 and 5.96 t ha-1. The interaction between water stress treatments and nano and metallic boron concentrations was significant for all the studied traits except for ear length.

Theoretical and Experimental Advances in High-Pressure Behaviors of Nanoparticles.

Using compressive mechanical forces, such as pressure, to induce crystallographic phase transitions and mesostructural changes while modulating material properties in nanoparticles (NPs) is a unique way to discover new phase behaviors, create novel nanostructures, and study emerging properties that are difficult to achieve under conventional conditions. In recent decades, NPs of a plethora of chemical compositions, sizes, shapes, surface ligands, and self-assembled mesostructures have been studied under pressure by in-situ scattering and/or spectroscopy techniques. As a result, the fundamental knowledge of pressure-structure-property relationships has been significantly improved, leading to a better understanding of the design guidelines for nanomaterial synthesis. In the present review, we discuss experimental progress in NP high-pressure research conducted primarily over roughly the past four years on semiconductor NPs, metal and metal oxide NPs, and perovskite NPs. We focus on the pressure-induced behaviors of NPs at both the atomic- and mesoscales, inorganic NP property changes upon compression, and the structural and property transitions of perovskite NPs under pressure. We further discuss in depth progress on molecular modeling, including simulations of ligand behavior, phase-change chalcogenides, layered transition metal dichalcogenides, boron nitride, and inorganic and hybrid organic-inorganic perovskites NPs. These models now provide both mechanistic explanations of experimental observations and predictive guidelines for future experimental design. We conclude with a summary and our insights on future directions for exploration of nanomaterial phase transition, coupling, growth, and nanoelectronic and photonic properties.

Insight on electrochemical charge storage behavior of naturally surface oxidized amorphous NiCuCoB nanosheets

Transition metal boron (TMB) nanostructures are found to be emerging materials in the field of energy conversion and storage. Despite several careful systematic researches on the TMBs and their electrochemical energy storage applications, still a comprehensive and insightful study on the charge storage mechanism, origin of the redox reaction sites on alloyed TMB surface, types of interactions of the electrolytes with respect to TMB's surface structure has not been realized. Herein, a series of TMBs nanosheets are prepared using Cu, Co, Ni and B through a simple low-cost reduction approach and explored systematically their charge storage behavior. Trimetallic NiCuCoB nanosheets over other TMBs demonstrated outstanding electrochemical energy storage performances with high-rate capability. A symmetric two-electrode coin cell device of NiCuCoB in 6.0 M KOH offers 358 F g−1 specific capacitance with 56 Wh kg−1 energy and 13,320 W kg−1 power density, with 50,000 cycling stability. Kinetically fluent faradaic redox reactions are favourably occurred by a surface-controlled mechanism with minor contribution from diffusion, which are facilitated by oxidized surface of NiCuCoB viz., metal-oxide and/or metal-oxy/hydroxide, a high surface area and high conductivity of the material, as evidenced by experiments.

Surface Growth of Boron Nitride Nanotubes through Boron Source Design

AbstractBoron nitride nanotubes (BNNTs) are promising materials due to their unique physical and chemical properties. Fabrication technologies based on gas‐phase reactions reduce the control and collection efficiency of BNNTs due to reactant and product dispersion within the reaction vessel. A surface growth method that allows for controllable growth of BNNTs in certain regions using a preburied boron source is introduced. This work leverages the high solubility of boron in metals to create a boronized layer on the surface which serves as the boron source to confine the growth of BNNTs. Dense and uniform BNNTs are obtained after loading catalysts onto the boronized substrate and annealing under ammonia. Confirmatory experiments demonstrate that the boride layer provides boron for BNNTs growth. Furthermore, the patterned growth of BNNTs is realized by patterning the boronizing region, demonstrating the controllability of this method. In addition, the Ni substrate with BNNTs growth exhibits better performance in corrosion resistance and thermal conductivity than pure Ni. This study introduces an alternative strategy for the surface growth of BNNTs based on boron source design, which offers new possibilities for the controllable preparation of BNNTs for various applications.

Synthesis of single‐phase high‐entropy diboride powders and their spheroidization process

AbstractSpherical (Zr.2Ti.2Ta.2Nb.2Mo.2)B2 powders with a uniform particle size distribution are successfully prepared using a novel industrial approach, which combines spray‐drying process and thermal plasma sintering technology together. In this, single‐phase (Zr.2Ti.2Ta.2Nb.2Mo.2)B2 powders are first synthesized via a borothermal reduction process using a mixture of individual metallic oxides and boron powders as starting materials. The influence of boron powder content on the structure of prepared powders is researched. Then, (Zr.2Ti.2Ta.2Nb.2Mo.2)B2 granules are prepared after wet‐grinding and spray‐drying process, which exhibit a spherical shape and homogeneous element distribution. RF induction thermal plasma is finally used to sinter the granulated particle, and the apparent density of sintered spherical powders is increased to 2.57 g/cm3 from 1.43 g/cm3. Such powders are in potential demand for additive manufacturing techniques, and the successful synthesis of spherical (Zr.2Ti.2Ta.2Nb.2Mo.2)B2 powders may guide the way toward the preparation of many other spherical high‐entropy diboride powders.