Boron Carbon Nitride Nanosheets Research Articles

Nanohybrids of BCN-Fe1-xS for Sodium and Lithium Hybrid Ion Capacitors.

Hybrid ion capacitors (HIC) are receiving a lot of attention due to their potential to achieve high energy and power densities, but they remain insufficient. It is imperative to explore outstanding and environmentally benign electrode materials to achieve high-performing HIC systems. Here, a unique boron carbon nitride (BCN)-based HIC system that comprises a microporous BCN structure and Fe1-xS nanoparticle incorporated BCN nanosheets (BNF) as cathode and anode, respectively is reported. The BNF is prepared through a facile one-pot calcination process using dithiooxamide (DTO), boric acid, and iron source. In situ, crystal growth of Fe1-xS facilitates the formation of BCN structure through the creation of holes/defects in the polymeric structure. The first principle density functional (DFT) theory simulations demonstrate the structural and electronic properties of the hybrid of BCN and Fe1-xS as compelling anode materials for HIC applications. The DFT calculations reveal that both BCN and BNF structures have excellent metallic characters with Li+ storage capacities of 128.4 and 1021.38mAhg-1respectively. These findings are confirmed experimentally where the BCN-based HIC system delivers exceptional energy and power densities of 267.5Whkg-1/749.5Wkg-1 toward Li+ storage, which outweighs previous HIC performances and demonstrates favorable performance for Li+ and Na+ storages.

Flower-like superstructure of boron carbon nitride nanosheets with adjustable band gaps for photocatalytic hydrogen peroxide production

The self-assembly of two-dimensional (2D) semiconductor nanosheets into three-dimensional (3D) ordered superstructures represents an ingenious way to avoid aggregation, expose massive available active sites and benefit the mass transfer, which maximizes the advantages of the 2D nanostructures in photocatalysis. Herein, a flower-like superstructure of ternary semiconducting boron carbon nitride nanosheets (FS-BCNNSs) was synthesized through the morphology-preserved thermal transformation of a flower-like superstructure of boron-containing metal-organic framework nanosheets (FS-MOFNSs). Taking advantage of this functional superstructure, FS-BCNNSs was employed for the pioneering application in the field of photocatalytic hydrogen peroxide (H2O2) production and exhibited excellent photocatalytic performance, yielding an impressive rate of 1415.9 μmol g−1 h−1 for the production of H2O2. The results of this work offer not just a promising catalyst for photocatalytic H2O2 production but also a facile strategy to fabricate unique superstructures constructed from 2D nanosheets for catalysis, energy conversion, and other related fields.

Boron carbon nitride nanosheets via induction plasma: Insights on synthesis, characterization, and control of band gap

Band gap-controlled two-dimensional boron carbon nitride nanosheets (BCNNS) were synthesized via a scalable one-step thermal plasma-based process near atmospheric pressure. Monotonic change in the band gap of BCNNS from 2.4 to 4.1 eV was achieved through manipulating the carbon loading during the nanosheet formation from ammonia borane and methane. Electron microscopy images showed 2D structures with sizes of 100–200 nm and 1.1–3.7 nm in sheet thickness (3–10 atomic layers). The sheets displayed non-uniformity in layer stacking and dislocation-type defects indicating the inclusion of BN in the C framework. Quasi-uniform distribution of the B/N/C was shown through energy dispersive X-ray spectroscopy. The presence of these elements as well as the sp2 hybridization of the bonding were confirmed using electron energy loss spectroscopy. Fourier Transform infrared spectroscopy showed the presence of B–N/BN, C–N/CN, and C–B/CB groups, and Raman spectroscopy showed progressive graphitization across the BCNNS samples as the BN content is decreased. The optical band gap of various samples is estimated using the Tauc method and found to increase as the carbon content decreased.

Photo-thermal synergistic catalytic oxidative dehydrogenation of propane over a spherical superstructure of boron carbon nitride nanosheets

The oxidative dehydrogenation of propane (ODHP) is an attractive reaction for increasing the production of light olefins due to its favorable thermodynamic and kinetic characteristics. However, the overoxidation of propene to thermodynamically favored COx leads to a trade-off between propane conversion and propene selectivity, limiting the optimization of the overall catalytic performance. Here we show that photo-thermal synergistic catalysis driven by a spherical superstructure of semiconducting boron carbon nitride nanosheets (SS-BCNNSs) breaks the conversion–selectivity trade-off, resulting in a remarkable enhancement of propane conversion, along with a well-maintained selectivity for propene under mild conditions. The mechanism study shows that the introduction of light irradiation during the ODHP process could change the reaction order, activate the reactants, and reduce the activation energy for ODHP. DFT calculations reveal that the photogenerated electrons provided by SS-BCNNSs promote oxygen adsorption and significantly reduce the energy barrier for generating active B-O·species, which in turn produces more active sites and enhances the reactivity.

Temperature controlled synthesis of boron carbon nitride nanosheets and study of their bandgap modulation and nonlinear optical properties

This work reports a novel mechanism to synthesize boron carbon nitride (BCN) nanosheets with varying carbon concentration where the whole process is controlled by temperature variation. The morphology, layer numbers, crystallinity, chemical composition and bonding of synthesized BCN nanosheets were confirmed by Field emission scanning electron microscopy (FESEM), Atomic force microscopy (AFM), Transmission electron microscopy (TEM), X-Ray photoelectron spectroscopy (XPS) and Energy Dispersive X-Ray Analysis (EDX). Molecular configuration and bonding vibration of the nanosheets and their linear optical and 3rd-order nonlinear optical properties were analyzed by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, UV–Vis spectroscopy and Z-scan technique respectively. The bandgap estimated from UV–Vis absorption data matches well with the theoretical values calculated by ab initio density functional theory (DFT) thus confirming the formation of BCN nanosheets. The thermal treatment of hBN in the graphitic environment is demonstrated to control the tuning of the morphological, structural, linear, and nonlinear optical characteristics of synthesized BCN nanosheets which currently pave the way of new opportunities for the development of tunable bandgap-based electronics and photonic devices.

Proximate white light-long phosphor emission and a photoelectrochemical probe from boron defects engineered carbon-nitride nanosheets

A recent surge in the study of a room temperature afterglow nanomaterial has surfaced. Considering its natural coverage of a wide emission spectrum and long afterglow with single light excitation have tinkled many multidisciplinary applications. A synthesis of nanosheets with white light phosphorescence at room temperature is arduous. The manuscript emphasizes on the photoelectrochemical response of room temperature proximate white light phosphorescence in boron carbon nitride nanosheets (BCNs), synthesized at consistent physical operands by varying the overall boron dopant. The study thus envisages the interplay of the participating precursors unfolding the physio-chemical interactions between boron/carbon and nitrogen needed towards the phosphorescence phenomenon. BCNs have provided an immense physio-chemical link between the analyte and photoanode under illuminated conditions, as found vital to achieve the reported sensitivity. Three varying boron conditions are examined, out of which, a 1:4 ratio (BCN-2) is distinguished for remarkable afterglow duration. In addition, the as-synthesized BCN-2 has been used for the photo-electrochemical detection of H2O2 via a differential pulse voltammetry method with a limit of detection of 25 nM. The after-glow property has shown a remarkable response toward H2O2 detection. The easy synthesis and reproducibility of these organic phosphors also prompt its propensity to replace commercially available toxic phosphors.

Synthesis of fluorescent boron carbon nitride nanosheets for the detection of Cu2+ ions and epinephrine

Synthesis of fluorescent BCNNSs for sensing Cu2+ ions and EP via a “turn-off” mechanism.

Adsorption behaviour of graphene, boron nitride and boron carbon nitride nanosheets towards pharmaceutical and personal care products

Due to their toxic effects and the occurrence of triclosan and triclocarban (pharmaceutical and personal care products) in the water sources, there is an unmet need to remove them through a suitable method. In this study, the first principle density functional theory calculations were used to study and compare the adsorptive removal of triclosan and triclocarban using graphene, boron nitride, and boron carbon nitride nanosheets. The electrostatic potential maps, electron density distributions, density of states plots and molecular orbital distributions were obtained from the optimized structures. The electrostatic potential maps revealed that charge accretion takes place during the adsorption. The Van der Waals surfaces revealed that the graphene, boron nitride, and boron carbon nitride nanosheets exhibited several sites through which they can interact with triclosan and triclocarban. The thermodynamic feasibility of the process was evaluated by calculating the adsorption energy and the recovery time. The adsorption of triclosan and triclocarban molecules on the graphene nanosheet was exothermic, with an energy value of −28.5 kJ/mol and −18.9 kJ/mol, respectively. The non-covalent interaction isosurfaces and reduced density scatter plots were obtained to examine the weak interactions. The feasibility of adsorption followed the order graphene > boron carbon nitride > boron nitride.

Comparative study on adsorption of volatile organic compounds on graphene, boron nitride and boron carbon nitride nanosheets

This computational study explores the adsorption of volatile organic compounds (VOCs), namely 1,3-butadiene, benzene, indole and toluene, using graphene (GRA), boron nitride (BN) and boron carbon nitride (BCN) nanosheets. The optimized structures obtained from the density functional theory computations and their vibrational frequencies were used to investigate the nature of the adsorption interactions. Based on HOMO and LUMO distributions, the variation in the orbital distributions during the adsorption was studied. The non-covalent interaction isosurfaces and reduced density gradient scatter plots were also obtained to understand the interactions during adsorption. The post-adsorption orientations of the VOCs over GRA, BN and BCN were parallel to the plane of the nanosheets. The computations indicated increased van der Waals interactions between the VOCs and the adsorbent sheets. The analysis showed that the VOCs interact with the nanosheets through weak van der Waal forces and showed π-π stacking. The overall analysis showed that the order of adsorption of VOCs on the nanosheets was: GRA > BCN > BN.

Boron Carbon Nitride Nanosheets-Ru Nanocomposite Self-Enhancement Electrochemiluminescence Emitter with a Three-Dimensional DNA Network Structure as a Signal Amplifier for Ultrasensitive Detection of TK1 mRNA.

In this study, a neoteric self-enhanced nanocomposite boron carbon nitride nanosheets (BCN NSs)-Ru obtained by chemical crosslinking between boron carbon nitride nanosheets (BCN NSs) and tris (4,4'-dicarboxylicacid-2,2'-bipyridyl) ruthenium(II) dichloride (Ru(dcbpy)3Cl2) was used as an emitter to build an electrochemiluminescence (ECL) biosensor for ultrasensitive detection of the cancer marker human thymidine kinase 1 (TK1) mRNA. Importantly, the self-enhanced BCN NSs-Ru could exhibit strong ECL emission because boron radicals and amine groups derived from BCN NSs could significantly enhance the ECL response of Ru(dcbpy)3Cl2, which avoided the defects of the long electron transfer path and large energy loss between the emitter and coreactant in the traditional coreaction ECL system. Impressively, in the presence of target TK1 mRNA, three-dimensional DNA network structure-labeled numerous ferrocene probes could be assembled to quickly quench the ECL signal of BCN NSs-Ru, resulting in improved biosensor sensitivity. The obtained "on-off" biosensor showed excellent stability and high sensitivity with a detection limit of 32.3 aM. In general, the developed strategy provided a new biosensing way for ultrasensitive detection of biomolecules in early disease diagnosis.

Anchoring ZnIn2S4 nanosheets on ultrathin boron carbon nitride layers for improved photo-redox catalysis

Ultrathin boron carbon nitride (BCN) nanosheets as fascinating candidates for advanced photocatalysis have aroused broad attention due to their highly stable physicochemical characteristics and potential chemical reaction carriers. However, its catalytic efficiency is ultimately limited by the sluggish kinetics of surface/interfacial photoexcitation charges and visible photons absorption. Herein, we report the exquisite design and construction of hierarchically layered heterostructures BCN-ZnIn2S4 that involve solution-processed surface growth of ZnIn2S4 subunits on the ultrathin sheet-shaped BCN nanostructures. The intimate interface contact of BCN and ZnIn2S4 architectures accelerate the separation/mobility of light-induced charges, as well as provides more active sites. In addition, the highly visible light response of the ZnIn2S4 component resulting from a suitable bandgap structure is favourable to the effective visible photons adsorption and utilization. The optimized BCN-ZnIn2S4 composite remarkably enhanced the photo-redox efficiency in the reductive CO2 deoxygenation (CO-releasing rate of 38.6 μmol h−1) and oxidative aromatic alcohols dehydrogenation (conversion of 81.6%) under visible light, which is 386-fold and 2-fold enhance performance compared to the pristine ultrathin BCN nanosheets, respectively.

Molten Salt Assisted Synthesis of Boron Carbon Nitride Nanosheets for Enhanced Photocatalytic Activity of Silver Phosphate

Thin 2D boron carbon nitride nanosheets (BCNNS) possess high thermal and chemical stability as well as tunable electronic properties, but the lack of effective synthesis methods hinders their practical application. Herein, a facile and efficient approach for the synthesis of large-area boron carbon nitride nanosheets in molten KCl–NaCl salt media has been proposed. A Single precursor compound, ethylenediamine bisborane, was first heated to 1000 °C in KCl–NaCl salt melts and then held for only two minutes to produce BCNNS. Benefiting from the effective solvation of precursors and reduced surface energy in liquid salt melt, the lateral size of resultant BCNNS can reach up to 12 microns. The as-prepared products are subsequently used as a co-catalyst with silver phosphate (Ag3PO4) for degradation methyl orange under simulated sunlight. Due to the improved electronic property and interfacial effect of BCNNS, the photocatalytic performance of Ag3PO4 was significantly improved. The photodegradation rate increased from 0.369 min−1 of Ag3PO4 to 1.006 min−1 of BCN/Ag3PO4 composite with only 0.6 wt% BCNNS loading, a 2.73-fold higher value than that of pure Ag3PO4.

Simultaneous adsorption of methylene blue and arsenic on graphene, boron nitride and boron carbon nitride nanosheets: Insights from molecular simulations

The occurrence of various pollutants in water bodies has become a serious concern. In this study, an attempt was made to find out the affinity of two-dimensional graphene (GRA), hexagonal boron nitride (h-BN) and hexagonal boron carbon nitride (h-BCN) towards the simultaneous adsorption of heavy metal (arsenic(III)) and organic dye (methylene blue) using molecular dynamics. The radial distribution functions obtained for the different systems showed that the OW-OW and OW-As pairs peaked around 3 Å whereas, for the As-As pair, the distribution showed a maximum at ~9 Å. The observations were consistent for all three nanosheets, irrespective of whether the adsorption occurred individually or simultaneously. The simultaneous adsorption was synergistic on all three nanosheets, of which the effect was maximum for graphene, indicating better efficiency for real wastewater treatment. Further, by integrating the radial distribution function, a coordination number of 12 was obtained for the arsenic(III) ions. The diffusion properties of water molecules during various adsorption interactions were studied by calculating the diffusion coefficients from the mean squared displacement curves. The density distributions were also examined to highlight how the water molecules surround the adsorbate ions. The orientation of the adsorbate molecules and their distance from the nanosheets were evaluated to propose a possible pathway by which the adsorption occurred. This study revealed that the potency of GRA for simultaneous adsorption of methylene blue and arsenic(III) was better than h-BN and h-BCN.

Synthesis and Characterization of Free-Standing Boron Carbon Nitride Nanosheets (Bcnns) in Inductively Coupled Plasma

Synthesis and Characterization of Free-Standing Boron Carbon Nitride Nanosheets (Bcnns) in Inductively Coupled Plasma

Defect states induced luminescence and electrochemical studies of boron carbon nitride nanosheets

A single-step thermochemical synthesis route for boron carbon nitride (BCN) has been reported in this work. X-ray photoelectron spectroscopy (XPS) shows that B, C, and N atoms are atomically intermixed with the dominance of graphite and BN domains. In Fourier transform infrared spectroscopy, a broad band at 1521 cm−1 (sp2 CN) indicates the presence of defect states comparable to the presence of πP (CN) plasmon loss peak in XPS. The role of defect states in the optical properties of BCN has been analyzed using UV–Visible and photoluminescence (PL) spectroscopy. PL shows a defect states induced broad emission band (2–2.9 eV) from the sp2 domain and a sharp peak at 3.64 eV due to band to band transitions of the direct band of BCN. Carbon played a significant role in the formation of deep levels responsible for the carrier trapping and recombination process. Defect induced emission in the ultraviolet and visible region makes this material suitable for optoelectronic, nanoelectronics, catalytic applications, etc. Hydrogen evolution reaction (HER) studies also show high performance due to presence of these defect states. The improved stability makes the material vital to be explored as electrode material in batteries and supercapacitors.

Tuning the Intermolecular Electron Transfer of Low-Dimensional and Metal-Free BCN/C60 Electrocatalysts via Interfacial Defects for Efficient Hydrogen and Oxygen Electrochemistry.

The development of low-dimensional (LD) supramolecular materials with multifunctional electrocatalytic properties has sparked the attention of the catalysis community. Herein, we report the synthesis of a new class of 0D-2D heterostructures composed of boron carbon nitride nanosheets (BCN NSs) and fullerene molecules (C60/F) that exhibit multifunctional electrocatalytic properties for the hydrogen evolution/oxidation reactions (HER/HOR) and the oxygen evolution/reduction reactions (OER/ORR). The electrocatalytic properties were studied with varying F:BCN weight ratios to optimize the intermolecular electron transfer (ET) from the BCN NSs to the electron-accepting C60 molecules. The nanohybrid supramolecular material with 10 wt % F in BCN NSs (10% F/BCN) exhibited the largest Raman and C 1s binding energy shifts, which were associated with greater cooperativity interactions and enhanced ET processes at the F/BCN interface. This synergistic interfacial phenomenon resulted in highly active catalytic sites that markedly boosted electrocatalytic activity of the material. The 10% F/BCN showed the highest tetrafunctional catalytic performance, outperforming the OER catalytic activity of commercial RuO2 catalysts with a η10 of 390 mV and very competitive onset potential values of -0.042 and 0.92 V vs RHE for HER and ORR, respectively, and a current density value of 1.47 mA cm-2 at 0.1 V vs RHE with an ultralow ΔGH* value of -0.03 eV toward the HOR process. Additionally, the 10% F/BCN catalyst was also used as both cathode and anode in a water splitting device, delivering a cell potential of 1.61 V to reach a current density of 10 mA cm-2.

Single-step synthesis of efficient nanometric boron carbon nitride semiconductor for photocatalysis

Carbon-based materials have demonstrated great advantages over other metal-based photocatalyst materials. With the recent development in textile industries, residual commercial dyes discharged out as wastewater is a serious environmental concern. Herein, we have developed Boron Carbon Nitride nanosheets via thermal condensation (TBCN) and solvothermal route (SBCN). X-ray diffraction, X-ray photoelectron spectroscopy and Ultraviolet-Diffuse Reflectance Spectroscopy used to describe the surface optical properties of as-prepared samples. The results were compared to identify a facile single-step route for the synthesis of pure BCN photocatalyst materials thereby to avoid additional treatments for purification of the synthesised material. The optical bandgap of TBCN was estimated to 2.68 eV, resembling a typical semiconductor. XPS study revealed the presence of residual starting material as impurities in the as synthesised SBCN sample. Photodegradation of Malachite green, Acid green and Reactive blue dyes were carried out using the synthesised samples and the photoactivity of TBCN & SBCN were studied. The BCN photocatalyst after photodegradation was further characterized to understand the structural change of the material. Toxicological studies were conducted using the treated and untreated water by Mung bean (Vigna radiata L.). Based on the results, this study provides a facile single-step approach for the synthesis of BCN with great durability and stability which are promising for removal of textile dyes from wastewater.

Molten salt synthesis of carbon-doped boron nitride nanosheets with enhanced adsorption performance

Owing to their large specific areas, high thermal stability and chemical inertness, two-dimensional boron carbon nitride nanosheets (BCNNs) have captured much attention in recent years in the field of adsorption of pollutants. The formation of BCNNs via incorporating carbon into boron nitride (BN) can effectively improve the photoelectric and adsorption properties of the latter. In this work, carbon-doped BN (BCN) nanosheets were prepared at 1100 °C via a molten salt route using boric acid, melamine and glucose as the main starting materials. The effects of molten salt type and carbon doping level on the formation of BCN were investigated, and their isothermal adsorption properties in a methylene blue (MB) aqueous solution were evaluated based on the Langmuir and Freundlich models. The results indicated that using molten LiCl-KCl as a liquid medium was more favorable than NaCl-KCl to the formation of BCNNs. As-prepared BC0.4N sample possessed a sheet-like structure of about 10 nm thick and a specific surface area as high as 484 m2 g−1. Moreover, the adsorption test of MB demonstrated a high adsorption capacity of 249.04 mg g−1, which was about 14 times higher than that in the case of the pristine BN, and the kinetic rate constant value in the case of using BC0.4N is about ten times as high as that of BN following a pseudo-second-order model, suggesting that the as-formed BC0.4N nanosheets could be potentially used as a value-added effective adsorbent for future wastewater remediation.

Molten salt assisted assembly growth of atomically thin boron carbon nitride nanosheets for photocatalytic H2 evolution.

Atomic-level boron carbon nitride nanosheets (BCNNS) have been prepared by a molten salt assisted assembly growth strategy, which effectively promotes the solvation of precursors, minimizes the surface energy and prevents the aggregation of layers. The as-synthesized BCNNS have atomic layered thickness and large lateral size, and show enhanced visible light H2 evolution activity compared to bulk BCN.

Forming a B[sbnd]B bond in boron carbon nitride composite: A way for metal free electrocatalyst for oxygen reduction reaction in alkaline medium

Unmanageable of oxygen electrochemistry on cathode side of fuel cells creates a major hindrance to designing a cell device. Effectively, Platinum alone cannot afford the oxygen reduction reaction (ORR) due to several worries such as unaffordable cost, stability, scarcity and intermediate tolerance etc. that would hurdle the development of fuel cell technology. In order to demonstrate similar efforts, we discuss a synthesis of boron carbon nitride (BCN) nanosheets and its composite by thermal and solvothermal method respectively. The BCN nanosheets also show the formation of a homonuclear BB bond, which are important for enhancing oxygen affinity. Since the chemistry of BB bond involves higher bond energy, more reactivity or unusual gas adsorption behavior, thus making such sites promising towards stronger electrophilic interactions such as oxygen adsorption followed by its reduction. As synthesized BCN exhibits an interesting onset potential of ∼0.94 V in electroreduction of oxygen. More importantly, upon composite formation with carbon black, BCN shows further enhancement in the ORR kinetics with an onset potential of 1.01 V and a current density of 5 mA/cm2, which is very much comparable with Pt/C. An interesting phenomenon of activating O2 reduction using BCN has been systematically studied to unravel noble metal-free electrocatalysis.