Boron Carbonitride Research Articles

Visible‐Light‐Induced C(sp2)−P Cross‐Coupling Reactions Catalyzed by Boron Carbonitride

A visible‐light‐induced protocol is developed for the construction of C(sp2)−P bonds with heterogeneous boron carbonitrides (BCN). The system features with broad scope and mild reaction conditions, providing various aryl phosphates in moderate to good yields from arenes and arylhalides. Mechanism studies verify a radical process, and C−H bond cleavage is not involved in the rate‐determined step. Furthermore, the strategy allows the late‐stage phosphonation of biologically active compounds and gram‐scale synthesis, which offers a metal‐free arene for valuable phosphorus‐containing compounds.

Accelerating catalytic conversion and chemisorption of polysulfides for advanced Li-S batteries from incorporating Fe0.64Ni0.36@Co5.47N hetero-nanocrystals into boron carbonitride nanotubes

With the rapid development of large-scale clean energy, lithium-sulfur (Li-S) batteries are considered to be one of the most promising energy storage devices. In this manuscript, the polymetallic hetero-nanocrystal of iron nickel@cobalt nitride encapsulating into boron carbonitride nanotubes (Fe0.64Ni0.36@Co5.47N@BCN) was designed and optimized for use as a modified material for commercial polypropylene (PP) separators. The prepared Fe0.64Ni0.36@Co5.47N@BCN-12 hybrid material presents strong chemisorption and catalytic conversion capabilities, which endows the Fe0.64Ni0.36@Co5.47N@BCN-12//PP separator with enhanced polysulfide shuttling inhibition. The assembled Li-S cells with Fe0.64Ni0.36@Co5.47N@BCN-12//PP separators have minimized charge transfer resistance and faster redox kinetics. Additionally, cells with Fe0.64Ni0.36@Co5.47N@BCN-12//PP separator provide high reversible capacity of 674 mAh/g for 400 cycles at 0.5C and excellent cyclability for 1000 cycles at 2C with a low decay rate of 0.05 % per cycle. Therefore, this study provides a feasible functionalization route for improving the electrochemical performance of Li-S batteries through separator modification.

Amorphous boron carbonitride (BC4N) from ab initio simulations

This study utilizes ab initio molecular dynamics simulations to explore the structure and properties of amorphous boron carbonitride (a-BC4N). A 432-atom model, generated via a conventional melt-and-quench technique, exhibits a graphite-like structure with all elements possessing an average coordination number of about 3.0. C atoms dominate within individual layers, interspersed with distinct BN domains. This atomic arrangement deviates considerably from that proposed for crystalline BC4N structures. Despite this structural variation, the a-BC4N model is likely a narrow band gap semiconductor (0.15 eV), similar to its crystalline counterparts. In terms of mechanical properties, a-BC4N demonstrates similarities with various layered materials while exhibiting a notably larger bulk modulus.

Tuning cross-plane thermal conductivity of multilayer graphene/h-BN vdW heterostructures via composition distribution

Nanomaterials with low thermal conductivity (TC) are ideal candidates as thermoelectric materials. In this direction, we design innovative multilayer graphene/h-BN (GBN) van der Waals (vdW) heterostructures with gradient composition distribution (C, B and N atoms), inspired by the newly synthesized boron carbonitride nanosheets. Three types of 26-layer GBN models are constructed and investigated, i.e. U-shape, X-shape, A-shape, representing uniform, symmetrical, and asymmetrical distributions of carbon atoms along the cross-plane direction, respectively. Based on non-equilibrium molecular dynamics (NEMD) simulation, we confirm that X-shape GBN model possess the lowest cross-plane TC, approximately 7 times smaller than that of the uniform U-shape graphene. The cross-plane TC can be further reduced by applying tensile strains or decreasing interlayer coupling strength. These findings elucidate the significant role the composition distribution plays in the thermal transport of GBN vdW heterostructures. However, the mechanical properties (Young's nodulus and tensile strength) of the new vdW heterostructures are insensitive to the composition distribution. Our work provides a new perspective for manipulating the interfacial thermal transport of multilayer GBN vdW heterostructures by means of material design and offers a useful guide for rationally designing thermoelectric materials with tailored thermal properties based on vdW heterostructures.

Tuning electronic environment of B sites in boron carbonitride nanoribbon boosts catalytic activity of reducing N2 to NH3

The electrocatalytic nitrogen reduction reaction (NRR) to synthesize ammonia is an important and challenging task in chemistry, where low-cost, highly active non-metallic catalysts such as boron carbonitride (BCN) are still highly desired. Tuning the electronic environment of the active site B is an effective approach to improve the NRR performance of BCNs. However, the study on the mechanism of this effect has been seriously neglected. The diversity and controllability in atomic arrangements of BCN make it suitable for studying the relationship between the local chemical environment of boron and the catalytic properties. To this end, we design four kinds of BCN materials named as homogeneous BCN nanoribbon and BCN nanosheet enriched with B − C active sites and localized phase-separated BCN nanoribbon and BCN nanosheet rich in B − N active sites, and theoretically screen the homogeneous type BCN nanoribbons that have better NRR performances. Meanwhile, we experimentally demonstrate that the optimized charge redistribution of B atoms in BCN skeleton by tuning the electronic environment makes the B − C sites being the effective centers in NRR, and arising the excellent NH3 productivity of 63.02 μg h−1 mg − 1 cat with a highest Faraday efficiency of 32.28 %.

Optical and electronic properties of BCN films deposited by magnetron sputtering.

Boron carbonitride (BCN) films containing hybridized bonds involving B, C, and N over wide compositional ranges enable an abundant variety of new materials, properties, and applications; however, their electronic performance is still limited by the presence of structural and electronic defects, yielding sluggish mobility and electrical conductivity. This work reports on mechanically stable BCN films and their corresponding optical and electronic properties. The ternary BCN films consisting of hybridized B-C-N bonds have been achieved by varying N2 flow by the radio frequency magnetron sputtering method. The BCN films show a bandgap value ranging from 3.32 to 3.82eV. Hall effect measurements reveal an n-type conductivity with an improved hall mobility of 226cm2/V s at room temperature for the optimal film. The n-BCN/p-Si heterojunctions exhibit a nonlinear rectifying characteristic, where the tunneling behavior dominates the injection regimes due to the density of defects, i.e., structural disorder and impurities. Our work demonstrates the tunable electrical properties of BCN/Si p-n diodes and, thus, is beneficial for the potential application in the fields of optics, optoelectronics, and electrics.

Structural, mechanical and electronic properties and phase transitions in superhard BC1-xNx: A first-principles study

First-principles investigations of the stability, mechanical properties, electronic and phonon structures, as well as molecular dynamics simulations of temperature- and pressure-induced phase transitions in boron carbonitrides, BC1-xNx, for x = 1.0 (C0), 0.75 (C1), 0.5 (C2), 0.25 (C3) and 0.0 (C4), were carried out. The plausible mechanisms of the phase transitions in BNs were proposed and the transformation paths were established for the h → w, r → c, c → r and w → h’ transitions, where h’ was the new hP4-187 phase (space group P-6m2, #187). The non-layered C0–C3 compounds transformed into the layered ones at 2000–3000 K. The new BC1-xNx structures are brittle materials and exhibit the best combination of hardness (23.1–60.8 GPa) and fracture toughness (4.03–5.23 MPa m1/2). The C1–C4 structures are metallic, except for three compounds: C1-oP8-25 and C4-tP8-136 are semi-metals, and C4-mP8-10 is a semiconductor with a very narrow bandgap of 0.2 eV.

Nonmetal Atom Doping Induced Orbital Shifts and Charge Modulation at the Edge of Two-Dimensional Boron Carbonitride Leading to Enhanced Photocatalytic Nitrogen Reduction.

Electronic structure, particularly charge state analysis, plays a crucial role in comprehending catalytic mechanisms. This study focuses on metal-free boron carbonitride (BCN) nanosheets as a case study to investigate the impact of heteroatom doping on the charge state of active sites at the edge of two-dimensional (2D) metal-free nanomaterials. Our observations revealed that the doping induces a shift in the frontier py orbital near the Fermi level, accompanied by alterations in its charge state. These changes provide insights into the nitrogen adsorption descriptors and the critical hydrogenation step, ultimately leading to the proposal of a competitive charge transfer mechanism. Additionally, this exploration has led to the screening of five BCN-type structures (P@T1-C1, S@T1-B1, O@T1-B1, P@T1-B1C2, and P@T1-B1C3) with promising nitrogen reduction reaction (NRR) performances. The BCN structure (S@T1-B1) exhibited the lowest NRR overpotential reaching -0.2 V, which is associated with the proposed charge competition mechanism. Furthermore, the investigation delves into the key step hydrogenation mechanism, descriptors, and volcano diagrams of the conformational relationships. In addition, the proposed doping strategy endows the 2D-BCN with more sensitivity toward the solar spectrum, suggesting its application as a potential photocatalyst. Overall, this study establishes a strong foundation for the advancement of nonmetal-atom-doped BCN nanosheets in nitrogen reduction applications, while also providing a versatile framework for fine-tuning edge-site activity within the broader context of two-dimensional photo/electrocatalytic materials.

Thermal characterization of carbon-rich boron carbonitride foams for thermal management applications

The increasing need to evacuate heat from electronic components encourages the use of new thermal materials. Motivated by the good heat convection of graphene foam (GF), we have integrated boron and nitrogen atoms into GF, thereby obtaining carbon-rich boron carbonitride (BCN) foam, which shows a significant improvement to its thermal characteristics. We used the infrared micro-thermography method and showed that carbon-rich BCN foam has an exceptionally large effective convection area and a high convection coefficient, which is comparable to that obtained under forced convection. Additionally, carbon-rich BCN foam presents remarkable thermal stability with a degradation temperature of ∼750 °C. Finally, we attached the carbon-rich BCN to an electric circuit and demonstrated its feasibility to evacuate heat from electronic components. Therefore, we pave the path for the integration of carbon-rich BCN foams in advanced thermal applications, such as thermal management reinforcement in composites and heat dissipation elements.

Multiscale Elasticity of 3D Boron Carbonitride Foam for Tunable Mechanical Resisting Devices

Multiscale Elasticity of 3D Boron Carbonitride Foam for Tunable Mechanical Resisting Devices

Tailoring the bandgap of zinc indium sulfide/boroncarbonitride heterostructure for efficient photocatalytic CO2 reduction

Many efforts have been devoted to the reduction of atmospheric CO2 and the development of a route map for sustainability in the energy and environmental sectors. The present work describes the bandgap tailoring of the ternary metal sulfide ZnIn2S4 (ZIS) with two-dimensional (2D) boroncarbonitride (BCN) and a constructed heterostructure. The ratio of BCN to ZIS has been varied in different ratios and examined for morphological, structural, and optical characterization. The crystalline structure of the synthesized materials was subjected to Materials Studio software, which examined the geometry, stacking, and interaction between ZIS and layered BCN. ZIS/BCN-1 is found to be efficient compared to all other counter catalysts under study. Diffuse reflectance infrared Fourier transform (DRIFT) and Gas Chromatography Mass spectrophotometry (GC-MS) analysis confirm the formation of carbon monoxide and methane gas. In the presence of ZIS/BCN-1, it was found to produce 158 and 57 μmol g−1h−1 of CO and CH4, respectively, during CO2 reduction under visible light. The effect of sacrificial agents has been investigated, and found that triethanolamine (TEOA) showed enhanced activity compared to others. The mechanism of photocatalysis has been discussed in detail and found to form type-II heterostructure through the interface between ZIS and BCN. The stability of ZIS/BCN-1 is good even after 5 cycles of the CO2 reduction experiment, and no structural changes were found.

Photosynthetic Fixation of CO2 in Alkenes by Heterogeneous Photoredox Catalysis with Visible Light

AbstractLight‐driven fixation of CO2 in organics has emerged as an appealing alternative for the synthesis of value‐added fine chemicals. Challenges remain in the transformation of CO2 as well as product selectivity due to its thermodynamic stability and kinetic inertness. Here we develop a boron carbonitride (BCN) with the abundant terminal B/N defects around the mesoporous walls, which essentially enhances surface active sites as well as charge transfer kinetics, boosting the overall rate of CO2 adsorption and activation. In this protocol, anti‐Markovnikov hydrocarboxylation of alkenes with CO2 to an extended carbon chain is achieved with good functional group tolerance and specific regioselectivity under visible‐light irradiation. The mechanistic studies demonstrate the formation of CO2 radical anion intermediate on defective boron carbonitride, leading to the anti‐Markovnikov carboxylation. Gram‐scale reaction, late‐stage carboxylation of natural products and synthesis of anti‐diabetic GPR40 agonists reveal the utility of this method. This study sheds new insight on the design and application of metal‐free semiconductors for the conversion of CO2 in an atom‐economic and sustainable manner.

Photosynthetic Fixation of CO2 in Alkenes by Heterogeneous Photoredox Catalysis with Visible Light.

Light-driven fixation of CO2 in organics has emerged as an appealing alternative for the synthesis of value-added fine chemicals. Challenges remain in the transformation of CO2 as well as product selectivity due to its thermodynamic stability and kinetic inertness. Here we develop a boron carbonitride (BCN) with the abundant terminal B/N defects around the mesoporous walls, which essentially enhances surface active sites as well as charge transfer kinetics, boosting the overall rate of CO2 adsorption and activation. In this protocol, anti-Markovnikov hydrocarboxylation of alkenes with CO2 to an extended carbon chain is achieved with good functional group tolerance and specific regioselectivity under visible-light irradiation. The mechanistic studies demonstrate the formation of CO2 radical anion intermediate on defective boron carbonitride, leading to the anti-Markovnikov carboxylation. Gram-scale reaction, late-stage carboxylation of natural products and synthesis of anti-diabetic GPR40 agonists reveal the utility of this method. This study sheds new insight on the design and application of metal-free semiconductors for the conversion of CO2 in an atom-economic and sustainable manner.

Boron Carbonitride Films with Tunable Composition: LPCVD and PECVD Synthesis Using Trimethylamine Borane and Nitrogen Mixture and Characterization

This study reports the chemical vapor deposition of amorphous boron carbonitride films on Si(100) and SiO2 substrates using a trimethylamine borane and nitrogen mixture. BCxNy films with different compositions were produced via variations in substrate temperature and type of gas-phase activation. The low-pressure chemical vapor deposition (LPCVD) and plasma-enhanced chemical vapor deposition (PECVD) methods were used. The “elemental composition—chemical bonding state—properties” relationship of synthesized BCxNy was systematically studied. The hydrophilicity, mechanical, and optical properties of the films are discussed in detail. The composition of films deposited by the LPCVD method at temperatures ranging from 673 to 973 K was close to that of boron carbide with a low nitrogen content (BCxNy). The refractive index of these films changed in the range from 2.43 to 2.56 and increased with temperature. The transparency of these films achieved 85%. LPCVD films were hydrophilic and the water contact angles varied between 53 and 63°; the surface free energy was 42–48 mN/m. The microhardness, Young’s modulus and elastic recovery of LPCVD films ranged within 24–28 GPa, 220–247 GPa, and 70–74%, respectively. The structure of the PECVD films was close to that of hexagonal boron nitride, and their composition can be described by the BCxNyOz:H formula. In case of the PECVD process, the smooth films were only produced at low deposition temperatures (373–523 K). The refractive index of these films ranged from 1.51 to 1.67. The transparency of these films achieved 95%; the optical band gap was evaluated as 4.92–5.28 eV. Unlike LPCVD films, they were very soft, and their microhardness, Young’s modulus and elastic recovery were 0.8–1.4 GPa, 25–26 GPa, and 19–28%, respectively. A set of optimized process parameters to fabricate LPCVD BCxNy films with improved mechanical and PECVD films with high transparency is suggested.

Green Diamond: A Superhard Boron Carbonitride with Bandgap in Green-Light Region and Anisotropic High Carrier Mobilities

The development of new multifunctional superhard materials beyond diamond is a great challenge for materials science and industry application. A new diamond-like boron carbonitride material (BC6N) formed by covalently alternated stacking of two-dimensional BC3 and C3N monolayers is systemically investigated through first-principles method. The electronic structure calculations show that the new structure is a direct bandgap semiconductor with a bandgap of 2.404 eV (HSE06). It exhibits anisotropic high carrier mobility (μLh = 1.88 × 104 cm2 V-1 s-1), varied absorbance in visible light and different regions of UV light, and theoretical Vickers hardness of 81.34 GPa, close to that of diamond. Furthermore, it is easily synthesizable due to its exothermic nature when reacted from the interlayer fusion of the BC3 and C3N monolayers in a bottom-up synthesis strategy. In addition, the properties of 3D-BC6N-I can be tuned by applying strain, changing stacking patterns, and 2D-nanolization. The excellent mechanical, electronic, and optical properties and good synthesizability suggest that the new structure (named as "green diamond") may find broad applications as a superhard and high-temperature material as well as a semiconductor and optical devices beyond diamond.

Facile Synthesis of Two-Dimensional (2D) Boron Carbonitride and 2D Porous Boron Carbonitride for Excellent Energy Storage and Gas Adsorption Applications

Facile Synthesis of Two-Dimensional (2D) Boron Carbonitride and 2D Porous Boron Carbonitride for Excellent Energy Storage and Gas Adsorption Applications

Mild and metal-free Birch-type hydrogenation of (hetero)arenes with boron carbonitride in water

Mild and metal-free Birch-type hydrogenation of (hetero)arenes with boron carbonitride in water

Boron carbonitride (BxCyNz) nanosheets based single electrode triboelectric nanogenerator for wearable UV photodetectors

Exposure to intense UV radiation is a life threatening issue for the Military personals posted at high altitude. We report on the first ever fabrication of boron carbonitride (BxCyNz) nanosheets based single electrode triboelectric nanogenerator (STENG) on wearable textile platform for ultraviolet (UV) photodetection. The 2D nature of the BxCyNz samples has been revealed from the microscopy-based characterization tools, while the UV absorption ability of the material has been analyzed using UV-visible absorption spectroscopy. During biomechanical action, the UV detection using the STENG can be realized by the event of lowering of output voltage under UV illumination. The observation of excellent photoresponsivity ∼ 1.6 × 103 V/W can be assigned to the nitrogen deficient microstructures of BxCyNz, offering trap states to facilitate electron-hole pair dissociation and their subsequent separation. However, the basic mechanism of photodetection relies on the increment of the inherent capacitance as a consequence photoexcitation in BxCyNz. As a significant outcome of this process, the output voltage of a load capacitor is found to be elevated under illumination and thus turns out to be an alternative method of photodetection. Finally, the photodetection characteristics and the signal transmitting ability of the STENG have been demonstrated upon attaching it to the human body. Thus, BxCyNz based STENG demonstrating photodetection through capacitive voltage growth can form as the basis of next generation flexible, smart and self-powered photodetectors.

Oxygen Functionalization-Induced Charging Effect on Boron Active Sites for High-Yield Electrocatalytic NH3 Production

HighlightsO-functionalization at the edges of boron carbonitride induces charge polarization effect on B.0.1 M HCl serves to preserve the catalyst active site from poisoning effect by electrolyte anions.Experimental and theoretical findings go hand-in-hand towards high yield of ammonia.

Investigating the effect of PDA/KH550 dual functionalized h-BCN nanosheets and hybrided with ZnO on corrosion and fouling resistance of epoxy coating: Experimental and DFT studies

In this work, two-dimensional hexagonal boron carbonitride nanosheets co-functionalized with polydopamine (PDA) and 3-aminopropyltriethoxysilane (KH550) (abbreviated as Fh-BCNNS) are introduced as nanofillers for promoting the fouling and physical barrier resistance of solvent-based epoxy coatings. The material characterization conducted with X-ray techniques of photoelectron spectroscopy and diffraction as well as Brunauer–Emmett–Teller confirm that the synthesized h-BCNNS has 353 m2/g specific surface area with microporous structure, while field emission scanning electron microscopy and Fourier transform infrared spectroscopy indicate that the co-functionalization is successfully achieved. After dispersing the Fh-BCNNS in the epoxy matrix at 0.3, 0.6, and 1.0 wt% followed by mixing with the curing agent, the coating is applied by a spray method on the steel surface. The data derived by electrochemical impedance spectroscopy show that the optimum corrosion resistant properties is achieved by loading 0.6 wt% Fh-BCNNS, and the coating resistance of the optimized nanocomposite is 3.7 × 107 and 2.85 × 106 Ω.cm2 after immersion in the corrosive electrolyte of 3.5 wt% NaCl aqueous solution for 1 day and 28 days, respectively. Furthermore, density functional theory (DFT) alongside the experimental investigations proves the mechanisms involved in corrosion protection properties through considering interactions and electronic properties. For EP/Fh-BCNNS@F-ZnO nanohybrid, the value of Zf= 0.01 Hz of EP/Fh-BCNNS@F-ZnO hybrids after 1 day and 4 weeks of immersion, are 9 × 107 and 3.3 × 107 Ω.cm2 which are two order of magnitude higher than EP/Fh-BCNNS. According to anti-fouling results, the growth rate of algae is less than 10% for the EP/Fh-BCNNS@F-ZnO sample and between 30% and 60% for the control sample (EP/Fh-BCNNS at 0.6 wt%) after 28 days of immersion.