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. 2021 Oct 15;6(42):27814–27822. doi: 10.1021/acsomega.1c03406

The Synthesis and Characterization of h-BN Nanosheets with High Yield and Crystallinity

Shaocheng Li 1, Xianlang Lu 1, Yanda Lou 1, Kejun Liu 1, Benxue Zou 1,*
PMCID: PMC8552327  PMID: 34722981

Abstract

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Nowadays, boron nitride (BN) has attracted a great deal of attention due to its physical and chemical properties, such as high-temperature resistance, oxidation resistance, heat conduction, electrical insulation, and neutron absorption. The unique lamellar, reticular, and tubular morphologies and physicochemical properties of BN make it attractive in the fields of adsorption, catalysis, hydrogen storage, thermal conduction, insulation, dielectric substrate of electronic devices, radiation protection, polymer composites, medicine, etc. Based on this, we propose a novel method to produce boron nitride nanosheets (BNNSs) by a two-step method. The structure and morphology of the prepared BNNSs were characterized by scanning electron microscopy, transmission electron microscopy, atomic force microscopy, XRD, FTIR, etc. The results showed that the prepared BNNSs had high crystallinity and the stripping efficiency of h-BN as well as the performance and yield of BNNSs had been improved, and the cost and environmental pollution of BNNS preparation had been reduced accordingly.

1. Introduction

Hexagonal boron nitride (h-BN) is known by the name white graphite.1−3 As an isoelectronic body of graphite, h-BN that possesses a graphene-like two-dimensional layered structure exhibits excellent insulation,4 thermal conductivity,5 and thermal stability.6,7 High-temperature resistance, pressure resistance, chemical corrosion resistance, anti-oxidation property, and good neutron radiation shielding performance make h-BN a new material with excellent performances and great development potential.8 The h-BN in-plane B and N atoms are associated by σ covalent bonds, forming a honeycomb-like structure with an interlayer thermal conductivity that can reach 300 W/(m·K) and still maintain its properties at 900 °C.9 Due to different p orbital energies of B and N atoms, the symmetry of the sublattice is destroyed, leaving h-BN with a high band gap width (5–6 eV) and the ability to be an ideal insulating material.10 A conventional h-BN crystal has large particle size, low specific surface area, natural tolerance to other chemicals, and lack of surface level molecular binding sites, which makes it difficult for h-BN to interface with other materials.11 By deeply functionalizing and nanosizing h-BN, it will not only improve the specific surface area active sites of h-BN but also increase the compatibility of h-BN with other molecules,12 which will open the applications of h-BN materials in many other emerging fields, such as aerospace,13 biomedicine,14 electronics,15 hydrogen storage,16 and so on. The following is a detailed description of some of its applications.

Talmon et al.,8 researchers from the University of Illinois, separated the boron nitride layer into atomically thick sheets with a super acid treatment and formed binding sites on the surface of the boron nitride atomically thick sheets, providing a two-dimensional interface with nanoparticles, molecules, and other devices for optoelectronic and piezoelectric devices, passivation layers for solar cells, medical diagnostic devices, and many other applications. Li et al.17 prepared monolayer boron nitride with a larger area by the vapor deposition method and reported for the first time that electric charge movement and transport can be performed in the plane of monolayer boron nitride, similar to organic semiconductor properties. Lu et al.18 exfoliated h-BN powder in thionyl chloride to produce BNNSs without using dispersion agents. Through using the deposition–precipitation method, Pd nanoparticles were immobilized onto BNNS surfaces to construct a Pd–BNNS catalyst that exhibited high catalytic activity and recyclability for the hydrogenation of nitro aromatics. In addition to this, Lu and his team also used molten citric acid to treat h-BN in order to produce aqueous dispersible boron nitride sheets.19 Then, they used said BNNSs to fabricate hydrogels with high water retentivity and flexibility, revealing the application prospect of BNNSs as a high-performance hydrogel. Miele and his team have proposed a new strategy for the production of PVA-based porous membranes using mainly water as solvent and hexagonal boron nitride nanosheets (BNNSs) as a stabilizer. The results show that BNNSs/PVA porous membranes fabricated by the Pickering emulsion template method are good candidates for use as microfiltration membranes.20 In addition to this, Miele and his team have reported a simple, effective, and green way for the fabrication of gelatin–graphene-like BN nanocomposites for gas barrier applications. The reinforcement effect of graphene-like BN on the gelatin properties is discussed. The obtained graphene-like BN nanocomposites show good dispersion in the gelatin matrix and remarkable capability to improve the crystallinity and the barrier properties of gelatin. The barrier properties of gelatin/BN nanocomposites have been enhanced by a factor of 500 at 2 bar compared to a gelatin film without graphene-like BN.21

While hexagonal boron nitride nanosheets (BNNSs) have thermal and mechanical properties similar to graphene,22 they also possess cathodic luminescence,23 electrical insulation,24 high thermal conductivity,24 thermal stability,25 and high-temperature antioxidant properties.26 BNNSs can also be used as polymer additives,27 carriers for nanoparticles,28 highly durable field emitters,29 superhydrophobic films,30 etc., making BNNSs have a huge application market and promise.31−33 Miele and his team have given a very detailed overview of synthetic methods for the production of boron nitride nanocomposites, especially polymer- and ceramic-based nanocomposites, and their potential applications in the fields of energy, environment, and health.34 This work has served as a great inspiration for the direction of future experiments.

Nevertheless, compared with graphene, h-BN shows stronger interlayer van der Waals force due to the existence of ionic bonds between adjacent layers, making boron nitride harder to intercalate and peel than graphene.35 Current methods for the preparation of BNNSs mainly include a “bottom-up” vapor deposition method36 and chemical exfoliation37 as well as “top-down” ultrasound-assisted solvent exfoliation38 and mechanical exfoliation method.39 Among them, the chemical vapor deposition (CVD) method, in which h-BN coating materials are obtained by reactive deposition using gaseous precursor species containing boron and nitrogen elements on the substrate surface, has a wide adjusting range of parameters, well-distributed and compact coated products, higher purity, and better thermal, force, electrical, and other properties compared with other methods.36 However, CVD preparation methods require extremely high temperatures, up to 900–1300 °C, as well as high equipment costs and low yield, making it difficult for large-scale production.40 The chemical exfoliation method, which draws on the chemical oxidation method to prepare graphene to achieve effective exfoliation, uses concentrated H2SO4, KMnO4, and H2O2 to chemically exfoliate h-BN.37 Although BNNSs can be obtained by this method, the yield is also low and the starting materials are neither green nor environmentally friendly.41 The mechanical ball milling method utilizes hard balls to peel bulk h-BN into a few layers or a single layer of boron nitride nanosheets under the action of high shear and impact forces.33 It has been proven that short ball milling time results in low stripping efficiency, while excessive ball milling time damages the BN structure, leading to severely decreased surface crystallinity and more crystal defects.42 In addition to the above methods, a green approach to prepare exfoliated hexagonal boron nitride nanosheets (BNNSs) has been presented by Miele and his team. The first step involves the dispersion of pristine h-BN within an aqueous solution containing gelatin and potassium or zinc chloride using a sonication method. The second step involves the removal of larger exfoliated BNNSs through a centrifugation procedure.43 The success of this experiment makes it possible to improve the yield of exfoliated BNNSs by controlling the different factors that may affect exfoliation. It also served as an irreplaceable inspiration for the design of this experiment.

Recently, in collaboration with Liaoning Dandong Institute of Chemical Research Co., Ltd., China, our college carried out the research work on functionalization and nanosizing of boron nitride, including surface modification of boron nitride, development of a boron-carbon-nitrogen composite, etc. The obtained boron-carbon-nitrogen composite exhibits an obvious 2D intercalation structure of boron nitride and graphene, which effectively reduces the band gap width of boron nitride and exhibits certain semiconductor properties and fine electrochemical sensing performance.44 In this study, submicrometer-sized h-BN was first synthesized via a high-temperature solid-phase method and the effects of different reaction media on the structure and morphology of h-BN were investigated. Then, the submicrometer-sized h-BN was used as a ball milling raw material to effectively exfoliate it by the mechanical ball milling method. The effects of factors such as additives on the structure and morphology of BNNSs were also investigated. The results of this study showed that the BNNSs with uniform size distribution, which possess advantages of high yield, simple postprocessing, and less pollution, can be obtained by appropriately adjusting factors such as the ball-to-material ratio and ball milling additives. To the best of our knowledge, this is the first time that a novel two-step method to produce boron nitride nanosheets (BNNSs) is reported.

2. Experimental Section

2.1. Materials

Boric acid was purchased from Bor Mining Cooperation (Russia) with a purity of 99.99%, and the CAS number is 10043-35-3. Melamine was provided by Shandong Helitai Chemical Co., Ltd. (China) with a purity of 99%, and the CAS number is 108-78-1. Sodium fluoride (99%, 7681-49-4), potassium chloride (99%, 7447-40-7), calcium chloride (99%, 10035-04-8), and sodium chloride (99.5%, 7647-14-5) were obtained from Sigma-Aldrich.

2.2. Preparation of Submicrometer-Sized h-BN

2.3. Preparation of h-BN Nanosheets

The submicrometer-scale h-BN and water were added into a planetary ball mill at a certain ratio by adding different sizes and ratios of zirconia balls and adjusting the planetary rotation speed and z-axis rotation speed with forward-reverse alternating operation, to perform the ball milling process. The sample was retrieved after ball milling was done. After that, the zirconia balls were washed with water to collect the washing solution that was then carried out by vacuum filtration with a microporous membrane with a pore size of 0.22 μm. The sample was washed several times with distilled water and then dispersed into distilled water or ethanol to obtain BNNS dispersions, which then went through vacuum drying to acquire BNNS powder. Determination of the concentration of the BNNS dispersion was as follows: After standing for a period of time, a certain volume of the upper liquid was taken out from the obtained BNNS dispersions with a pipette gun and transferred to a clean vial that had been weighed. Then, the vial was placed in a drying oven to dry at 90 °C for 24 h to evaporate the solvent. The total mass of the vial and the dry solid was weighed, and the concentration of nanosheets was calculated by the subtractive method, as shown below.

2.3. 1

where C stands for the concentration of boron nitride nanosheet dispersion (mg/mL), M stands for total mass of the vial and solid dry matter, m stands for the mass of vial (mg), and V stands for the volume of the removed upper liquid (mL).

2.4. Characterization

Morphologies of the samples were investigated by field emission scanning electron microscopy (SEM, FEI, Quanta FEG250, USA) and transmission electron microscopy (TEM, FEI, Tecnai G2 F20, USA). The Fourier translation infrared spectra were recorded on an FT-IR spectrometer (FT-IR, PerkinElmer, Spectrum Two, USA), using the KBr pelleting method. The crystalline phases of the samples were determined by an X-ray diffractometer (XRD, PANalytical B.V., Thermo Scientific, Netherlands). Atomic force microscopy (AFM) analysis was performed by employing an atomic force microscope (AFM, Multimode 8 Nanoscope V system, USA). EDS measurement was performed using a Zeiss EVO ED15 microscope coupled with an Oxford X-MaxN EDS detector. Surface compositions of BNNSs were observed by X-ray photoelectron spectroscopy (XPS, Kratos Axis Ultra DLD). The Raman spectra were obtained from a Horiba xplora. The yield of BNNSs was calculated using the following equation:

2.4. 2

3. Results and Discussion

3.1. Characterization of Submicrometer h-BN

3.1.1. SEM of Submicrometer h-BN

Based on the complex heterogeneous reaction of solid boron-nitrogen sources after heating, the following physical and chemical changes occur in turn with the increase of temperature, as shown in Figure 1: (a) formation of amorphous boron oxide from the boron source, (b) deamination polycondensation occurred on the nitrogen source, (c) the reaction of newly formed ammonia with boroxides, (d) reaction of boroxides with polycondensation products, (e) ring-opening pyrolysis of polycondensation products, (f) formation of amorphous boron-carbon-nitrogen-oxygen compounds, (g) melting of boroxides and reaction additives, and (h) formation of spherical boron nitride by decarburization and deoxidation of boron-carbon-nitrogen-oxygen compounds in melt. Figure 2 shows the scanning electron micrograph of submicrometer-sized h-BN obtained after the high-temperature solid-phase reaction at 1200 °C for 8 h, from which it can be seen that the particle size of h-BN is submicrometer sized. The particle size of h-BN was between 200 and 500 nm and evenly distributed.

Figure 1.

Figure 1

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Flow chart of the reaction of solid boron-nitrogen sources after heating.

Figure 2.

Figure 2

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SEM images of submicrometer h-BN.

3.1.2. Effects of Molten Salts on Submicrometer H-BN

Solid-phase reactions in which a certain amount of reaction media, such as alkali molten salts (NaF, CaF2, NaCl, KCl, etc.) or alkaline earth metal halides (CaCl2, etc.), was added to the solution have an effect both on the formation of submicrometer h-BN and the particle size. The addition of molten salt reduces the temperature required for the solid-phase reaction, thus reducing the particle size of the product. Figure 3 shows average particle scales of h-BN synthesized with different molten salts, from which it can be seen that well-dispersed submicrometer globular particles could be obtained from all four kinds of molten salts, in which the particles of h-BN obtained by sodium salt had a smaller average size. However, the addition of molten salt may cause some corrosion on the high-temperature reaction furnace.

Figure 3.

Figure 3

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Average particle size of h-BN synthesized with different molten salts.

In addition, factors such as the ratio of raw materials and heating rate have a certain effect on the synthesis of submicrometer h-BN. The amount of fumes at roasting and the subsequent processing volume will increase, and boronic acid feedstock will be wasted if the mass ratio of the nitrogen source and boronic acid is too low. In contrast, an excessive ratio would lead to the failure to form submicrometer boron nitride. The reaction temperature should be controlled between 900 and 1200 °C, below which it will lead to an extremely slow reaction. Above this temperature range, it will lead to the boron nitride crystals’ overgrowth to a micrometer scale; hence, it more easily acquires agglomerated products with irregular shape, which will lead to the formation of products with larger particles. The heat holding time is 2 to 4 h; a shorter time leads to an incomplete deoxygenation reaction, while a longer holding time causes boron nitride particles to grow larger.

3.2. Characterization of BNNSs

3.2.1. TEM of BNNSs

Figure 4 shows the transmission electron micrographs (TEM) of BNNSs obtained after the mechanical ball milling process of submicrometer h-BN under different magnifications. As shown in Figure 4, the obtained BNNSs are transparent and well distributed, exhibiting a wrinkled structure with graphene-like edges with a small amount of agglomeration. The thickness of BNNSs is about 4 to 10 nm, while the number of BNNS layers ranges from about 5 to 15. This indicates that after mechanical ball milling, h-BN was effectively exfoliated. The exfoliated BNNSs could be well dispersed in aqueous solution to form a homogeneous dispersion with an overall creamy white color. The obtained dispersions appear to be homogeneous and stable with concentrations up to 100 mg/mL.

Figure 4.

Figure 4

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TEM images of BNNs obtained from submicrometer-scale h-BN after ball milling under magnifications of (a) 5000 times, (b) 12,500 times, (c) 25,000 times, and (d) 50,000 times.

Figure 5 consists of TEM photographs of BNNSs obtained by mechanical ball milling of commercially available h-BN (23 μm D50) with a large average size of 23 μm. As shown in Figure 5, the obtained BNNSs are heterogeneous in thickness with low transparency of the sheet-like structure of h-BN. It does not exhibit an obvious graphene-like puckered structure and has more edge defects, the thickness of which is about 7 to 25 nm and the number of BNNS layers ranges from about 10 to 25.

Figure 5.

Figure 5

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TEM images of BNNSs obtained from commercially available h-BN (23 μm D50) after ball milling under magnifications of (a) 5000 times, (b) 12,500 times, (c) 25,000 times, and (d) 50,000 times.

3.2.2. XRD Patterns of BNNSs

Figure 6 shows the XRD spectra of submicrometer h-BN and commercially available h-BN before and after ball milling exfoliation, which all have typical 26.5, 41.5, and 55.1° diffractions of h-BN, corresponding to the (002), (100), and (004) facet diffraction peaks of h-BN, respectively. As can be seen from Figure 6c–e, the crystallinity of BNNSs after exfoliation was fairly good. After comparing (a) and (b) with (c), (d), and (e), it can been seen that the crystal system of the samples did not change by ball milling.

Figure 6.

Figure 6

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XRD spectra of (a) submicrometer h-BN, (b) commercially available h-BN (23 μm D50), (c) BNNSs obtained from submicrometer h-BN with additives, (d) BNNSs obtained from submicrometer h-BN, and (e) BNNSs obtained from commercially available h-BN (23 μm D50).

3.2.3. FTIR Spectroscopy of BNNSs

By comparing the five FTIR spectra in Figure 7, it can be seen that the peaks before and after ball milling are quite different, indicating that the submicrometer h-BN and commercially available h-BN were effectively exfoliated. The peak at 814 cm–1 can be seen in the figure as deformation vibration of the B–N bond. The peak at 1384 cm–1 indicates the stretching vibration of the B–N bond, which is more obvious for BNNSs than h-BN.

Figure 7.

Figure 7

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Fourier translation infrared spectra of (a) submicrometer h-BN, (b) commercially available h-BN (23 μm D50), (c) BNNSs obtained from submicrometer h-BN, (d) BNNSs obtained from commercially available h-BN (23 μm D50), and (e) BNNSs obtained from submicrometer h-BN with additives.

3.2.4. Characterization of Purity of BNNSs

SEM and EDS analyses of BNNSs obtained by the ball milling process from submicrometer h-BN are shown in Figure 8a,b, from which it can be seen that B, N, and O were detected and uniformly distributed in the sample. Combined with the XPS analysis shown in Figure 8c–e, the synthesis of BNNSs is successful. As can be seen in the Raman spectra of the two kinds of obtained BNNSs in Figure 8f, the peak at 1360 cm–1 is the specific vibrational mode (E2g) of h-BN, which was caused by the plane vibration of the sp2 hybridized B—N=B bond. The more intense and narrow peak indicates less defect structures. Clearly, BNNSs obtained from submicrometer h-BN have a better structure than those obtained from commercially available h-BN.

Figure 8.

Figure 8

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(a, b) SEM and corresponding elemental distribution diagrams (EDS) of BNNSs obtained from submicrometer h-BN through the ball milling process; (c–e) XPS of BNNSs obtained through the ball milling process of submicrometer h-BN; (f) the Raman spectra of BNNSs obtained by ball milling of submicrometer h-BN and commercially available h-BN (23 μm D50).

3.2.5. Effects of Ball Milling Additives on the BNNS Structure

Adding different kinds of additives during the ball milling process, such as hydrophilic and lipophilic amine-based molecules, affects the structure and size of BNNSs to some extent. Adding a certain amount of dopamine makes products appear off-white and hardly sedimentate within 72 h while the dispersion was homogeneous and stable. Therefore, due to the insertion of dopamine molecules in the h-BN interlayer during ball milling promoting the exfoliation process, the addition of an appropriate amount of ball milling additives would contribute to the effective exfoliation of h-BN to a certain level. However, the existence of dopamine can also bring impurities into the product, which increases the difficulty of separation and washing of subsequent products. As shown in Figure 9, the obtained BNNSs appear to be transparent and more evenly distributed. However, prisms of the edge of nanosheets become smaller and most of them appear circular. Thickness is about 2 to 10 nm and the number of BNNS layers ranges from 3 to 15, which indicates that the atomic interaction between amine molecules and the edge structure of h-BN promotes the effective exfoliation of h-BN.

Figure 9.

Figure 9

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TEM images of BNNSs obtained from submicrometer-scale h-BN after ball milling with additives under magnifications of (a) 5000 times and (b) 50,000 times.

The AFM photographs and height characterization of BNNSs deposited on the silicon chip are shown in Figure 10. It can be seen that BNNSs obtained from commercially available h-BN (23 μm D50) have larger thickness, while BNNSs obtained from submicrometer h-BN show smaller thickness (≤5 nm) and less layer structures. This result once again confirms that the submicrometer h-BN prepared by this method is better than commercially available h-BN (23 μm D50).

Figure 10.

Figure 10

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AFM and height images of BNNSs obtained from (a) commercially available h-BN (23 μm D50) and (b) submicrometer h-BN.

4. Conclusions

Submicrometer-sized h-BN was first synthesized by the high-temperature solid-phase method. The reaction conditions that include reaction temperature, reaction medium, and reaction time have a large effect on the structure and morphology of h-BN. With the reaction temperature ranging from 900 to 1200 °C and the reaction time ranging from 8 to 10 h, the synthesized h-BN particles were uniform with high crystallinity and submicrometer-scale particle size. Then, submicrometer-scale h-BN was used as a ball milling raw material to be effectively exfoliated by the wet ball milling technique. The results of this study showed that the BNNSs with uniform size distribution, which possesses advantages of a fairly high yield of 73%, simple postprocessing, and less pollution, can be obtained by appropriately adjusting factors such as the ball-to-material ratio and ball milling additives.

Acknowledgments

This work was supported by the National Natural Science Foundation of China (51873084).

Supporting Information Available

The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acsomega.1c03406.

  • Comparison of yield of BNNSs and cost of BNNS product (PDF)

The authors declare no competing financial interest.

Supplementary Material

ao1c03406_si_001.pdf (89.1KB, pdf)

References

  1. de los Reyes C. A.; Hernández K.; Martínez-Jiménez C.; Walz Mitra K. L.; Ginestra C.; Smith McWilliams A. D.; Pasquali M.; Martí A. A. Tunable Alkylation of White Graphene (Hexagonal Boron Nitride) Using Reductive Conditions. J. Phys. Chem. C 2019, 123, 19725–19733. 10.1021/acs.jpcc.9b05416. [DOI] [Google Scholar]
  2. Yu C.; Zhang J.; Tian W.; Fan X.; Yao Y. Polymer composites based on hexagonal boron nitride and their application in thermally conductive composites. RSC Adv. 2018, 8, 21948–21967. 10.1039/C8RA02685H. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Jedrzejczak-Silicka M.; Trukawka M.; Dudziak M.; Piotrowska K.; Mijowska E. Hexagonal Boron Nitride Functionalized with Au Nanoparticles-Properties and Potential Biological Applications. Nanomaterials 2018, 8, 605. 10.3390/nano8080605. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. He L.; Zeng J.; Huang Y.; Yang X.; Li D.; Chen Y.; Yang X.; Wang D.; Zhang Y.; Fu Z. Enhanced Thermal Conductivity and Dielectric Properties of h-BN/LDPE Composites. Materials 2020, 13, 4738. 10.3390/ma13214738. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Wan D.; Wu X.; Zhang W.; Peng K. Thermal conductivity and thermal expansion of few-layer h-BN/Cu composites. Mater. Res. Bull. 2019, 120, 110606. 10.1016/j.materresbull.2019.110606. [DOI] [Google Scholar]
  6. Fan D.; Lv X.; Feng J.; Zhang S.; Xie J.; Liu J. Integrating CoNi nanoparticles encapsulated by few-layer h-BN with excellent thermal conductivity and thermal stability. J. Alloys Compd. 2017, 704, 701–706. 10.1016/j.jallcom.2017.02.093. [DOI] [Google Scholar]
  7. Randhawa K. S.; Patel A. D. Enhancing tribo-mechanical properties and thermal stability of nylon 6 by hexagonal boron nitride fillers. E-Polymers 2020, 20, 733–745. 10.1515/epoly-2020-0069. [DOI] [Google Scholar]
  8. Kleinerman O.; Adnan M.; Marincel D. M.; Anson W. K.; Ma A. W.; Bengio E. A.; Park C.; Chu S. H.; Pasquali M.; Talmon Y. Dissolution and Characterization of Boron Nitride Nanotubes in Superacid. Langmuir 2017, 33, 14340–14346. 10.1021/acs.langmuir.7b03461. [DOI] [PubMed] [Google Scholar]
  9. Hu Y.; Yin Y.; Ding G.; Liu J.; Zhou H.; Feng W.; Zhang G.; Li D. High thermal conductivity in covalently bonded bi-layer honeycomb boron arsenide. Mater. Today Phys. 2021, 17, 100346. 10.1016/j.mtphys.2021.100346. [DOI] [Google Scholar]
  10. Ahmadi M. T.; Razmdideh A.; Rahimian Koloor S. S.; Petrů M. Carbon-Based Band Gap Engineering in the h-BN Analytical Modeling. Materials 2020, 13, 1026. 10.3390/ma13051026. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Kim M.; Moon S. W.; Kim G.; Yoon S. I.; Kim K.; Min S. K.; Shin H. S. Effect of Pt Crystal Surface on Hydrogenation of Monolayer h-BN and Its Conversion to Graphene. Chem. Mater. 2020, 32, 4584–4590. 10.1021/acs.chemmater.0c00736. [DOI] [Google Scholar]
  12. Zhang Z.; Duan X.; Qiu B.; Chen L.; Cai D.; He P.; Yang Z.; Jia D.; Zhou Y. Improvement of grain size and crystallization degree of LPSed h-BN composite ceramics by amorphization/nanocrystallization of raw h-BN powders. J. Alloys Compd. 2021, 852, 156765. 10.1016/j.jallcom.2020.156765. [DOI] [Google Scholar]
  13. Wu L.; Luo N.; Xie Z.; Liu Y.; Chen F.; Fu Q. Improved breakdown strength of Poly(vinylidene Fluoride)-based composites by using all ball-milled hexagonal boron nitride sheets without centrifugation. Compos. Sci. Technol. 2020, 190, 108046. 10.1016/j.compscitech.2020.108046. [DOI] [Google Scholar]
  14. Tozar A.; Karahan İ. H.; Yücel Y. Optimization of the Electrophoretic Deposition Parameters for Biocomposite Hydroxyapatite/Chitosan/Collagen/h-BN Coatings on Ti6Al4V Biomedical Implants. Metall. Mater. Trans. A 2019, 50, 1009–1020. 10.1007/s11661-018-5010-8. [DOI] [Google Scholar]
  15. Ouyang H.; Li W.; Long Y. Carbon-doped h-BN for the enhanced electrochemical determination of dopamine. Electrochim. Acta 2021, 369, 137682. 10.1016/j.electacta.2020.137682. [DOI] [Google Scholar]
  16. Aal S. A.; Alfuhaidi A. K. Enhancement of hydrogen storage capacities of Co and Pt functionalized h-BN nanosheet: Theoretical study. Vacuum 2021, 183, 109838. 10.1016/j.vacuum.2020.109838. [DOI] [Google Scholar]
  17. Chen T.-A.; Chuu C.-P.; Tseng C.-C.; Wen C.-K.; Philip H.-S.; Pan S.; Li R.; Chao T.-A.; Chueh W.-C.; Zhang Y.; Fu Q.; Yakobson B. I.; Chang W.-H.; Li L.-J. Wafer-scale single-crystal hexagonal boron nitride monolayers on Cu(111). Nature 2020, 579, 219–223. 10.1038/s41586-020-2009-2. [DOI] [PubMed] [Google Scholar]
  18. Sun W.; Meng Y.; Fu Q.; Wang F.; Wang G.; Gao W.; Huang X.; Lu F. High-Yield Production of Boron Nitride Nanosheets and Its Uses as a Catalyst Support for Hydrogenation of Nitroaromatics. ACS Appl. Mater. Interfaces 2016, 8, 9881. 10.1021/acsami.6b01008. [DOI] [PubMed] [Google Scholar]
  19. Hu X.; Liu J.; He Q.; Meng Y.; Cao L.; Sun Y.-P.; Chen J.; Lu F. Aqueous compatible boron nitride nanosheets for high-performance hydrogels. Nanoscale 2016, 8, 4260. 10.1039/C5NR07578E. [DOI] [PubMed] [Google Scholar]
  20. Gonzalez-Ortiz D.; Pochat-Bohatier C.; Gassara S.; Cambedouzou J.; Bechelany M.; Miele P. Development of novel h-BNNS/PVA porous membranes via Pickering emulsion templating. Green Chem. 2018, 20, 4319–4329. 10.1039/C8GC01983E. [DOI] [Google Scholar]
  21. Biscarat J.; Bechelany M.; Pochat-Bohatier C.; Miele P. Graphene-like BN/gelatin nanobiocomposites for gas barrier applications. Nanoscale 2015, 7, 613–618. 10.1039/C4NR05268D. [DOI] [PubMed] [Google Scholar]
  22. Hwang G.; Kwon Y.; Lee J.; Jeong Y. Enhanced mechanical and anisotropic thermal conductive properties of polyimide nanocomposite films reinforced with hexagonal boron nitride nanosheets. J. Appl. Polym. Sci. 2020, 138, 50324. [Google Scholar]
  23. Zheng L.; Liu Z.; Liu D.; Wang X.; Li Y.; Jiang M.; Lin F.; Zhang H.; Shen B.; Zhu X.; Gong Y.; Fang Z. Deep subwavelength control of valley polarized cathodoluminescence in h-BN/WSe2/h-BN heterostructure. Nat. Commun. 2021, 12, 291. 10.1038/s41467-020-20545-x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Liu H.; Su X.; Fu R.; Wu B.; Chen X. The flexible film of SCF/BN/PDMS composites with high thermal conductivity and electrical insulation. Compos. Commun. 2021, 23, 100573. 10.1016/j.coco.2020.100573. [DOI] [Google Scholar]
  25. Chen F.; Li Z.; Zou L.-F.; Ma W.-J.; Li J.-W.; Chen Z.; Niu Z.-B.; Liu P.-F.; Xiao P. Tribological behavior and mechanism of h-BN modified copper metal matrix composites paired with C/C-SiC. Tribol. Int. 2021, 153, 106561. 10.1016/j.triboint.2020.106561. [DOI] [Google Scholar]
  26. Zhang C.; Gao B.; Ran Y.; Shi Z.; Zhu H.; Zhang H.; Liu J.; Yang B.; Liu Z.; Wu T.; Xie X. Silicon-Assisted Growth of Hexagonal Boron Nitride to Improve Oxidation Resistance of Germanium. 2D Mater. 2021, 8, 035041 10.1088/2053-1583/ac0298. [DOI] [Google Scholar]
  27. Xie Z.; Wu K.; Liu D.; Zhang Q.; Fu Q. One-Step Alkyl-Modification on Boron Nitride Nanosheets for Polypropylene Nanocomposites with Enhanced Thermal Conductivity and Ultra-Low Dielectric Loss. Compos. Sci. Technol. 2021, 208, 108756. 10.1016/j.compscitech.2021.108756. [DOI] [Google Scholar]
  28. Qiu J.; Wu T.; Qu J. Fabrication of iron oxide nanoparticle decorated boron nitride nanosheet for flame-retarding silicone rubber. Mater. Lett. 2021, 283, 128712. 10.1016/j.matlet.2020.128712. [DOI] [Google Scholar]
  29. Sajid A.; Ford M. J.; Reimers J. R. Single-photon emitters in hexagonal boron nitride: a review of progress. Rep. Prog. Phys. 2020, 83, 044501 10.1088/1361-6633/ab6310. [DOI] [PubMed] [Google Scholar]
  30. Abbas S.; Abbas A.; Liu Z.; Tang C. The two-dimensional boron nitride hierarchical nanostructures: Controllable synthesis and superhydrophobicity. Mater. Chem. Phys. 2020, 240, 122145. 10.1016/j.matchemphys.2019.122145. [DOI] [Google Scholar]
  31. Kim J. H.; Pham T. V.; Hwang J. H.; Kim C. S.; Kim M. J. Boron nitride nanotubes: synthesis and applications. Nano Converg. 2018, 5, 17. 10.1186/s40580-018-0149-y. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Wang X.; Yang Y.; Jiang G.; Yuan Z.; Yuan S. A facile synthesis of boron nitride nanosheets and their potential application in dye adsorption. Diamond Relat. Mater. 2018, 81, 89–95. 10.1016/j.diamond.2017.11.012. [DOI] [Google Scholar]
  33. Yang N.; Ji H.; Jiang X.; Qu X.; Zhang X.; Zhang Y.; Liu B. Preparation of Boron Nitride Nanoplatelets via Amino Acid Assisted Ball Milling: Towards Thermal Conductivity Application. Nanomaterials 2020, 10, 1652. 10.3390/nano10091652. [DOI] [PMC free article] [PubMed] [Google Scholar]
  34. Gonzalez-Ortiz D.; Salameh C.; Bechelany M.; Miele P. Nanostructured boron nitride-based materials: synthesis and applications. Mater. Today Adv. 2020, 8, 100107. 10.1016/j.mtadv.2020.100107. [DOI] [Google Scholar]
  35. Li Y.; Zhang W.; Guo B.; Datta D. Interlayer shear of nanomaterials: Graphene-graphene, boron nitride-boron nitride and graphene-boron nitride. Acta Mech. Solida Sin. 2017, 30, 234–240. 10.1016/j.camss.2017.05.002. [DOI] [Google Scholar]
  36. Han R.; Khan M. H.; Angeloski A.; Casillas G.; Yoon C. W.; Sun X.; Huang Z. Hexagonal Boron Nitride Nanosheets Grown via Chemical Vapor Deposition for Silver Protection. Acs Appl. Nano Mater. 2019, 2, 2830–2835. 10.1021/acsanm.9b00298. [DOI] [Google Scholar]
  37. Ikram M.; Jahan I.; Haider A.; Hassan J.; Ul-Hamid A.; Imran M.; Haider J.; Shahzadi A.; Shahbaz A.; Ali S. Bactericidal behavior of chemically exfoliated boron nitride nanosheets doped with zirconium. Appl. Nanosci. 2020, 10, 2339–2349. 10.1007/s13204-020-01412-z. [DOI] [PMC free article] [PubMed] [Google Scholar]
  38. Tian Z.; Chen K.; Sun S.; Zhang J.; Cui W.; Xie Z.; Liu G. Crystalline boron nitride nanosheets by sonication-assisted hydrothermal exfoliation. J. Adv. Ceram. 2019, 8, 72–78. 10.1007/s40145-018-0293-1. [DOI] [Google Scholar]
  39. Kumar R.; Singh R. K.; Yadav S. K.; Savu R.; Moshkalev S. A. Mechanical pressure induced chemical cutting of boron nitride sheets into boron nitride quantum dots and optical properties. J. Alloys Compd. 2016, 683, 38–45. 10.1016/j.jallcom.2016.05.073. [DOI] [Google Scholar]
  40. Chen X.; Tan C.; Liu X.; Luan K.; Guan Y.; Liu X.; Zhao J.; Hou L.; Gao Y.; Chen Z. Growth of hexagonal boron nitride films on silicon substrates by low-pressure chemical vapor deposition. J. Mater. Sci.-Mater. Electron. 2021, 32, 3713–3719. 10.1007/s10854-020-05116-6. [DOI] [Google Scholar]
  41. Ikram M.; Hussain I.; Hassan J.; Haider A.; Imran M.; Aqeel M.; Ul-Hamid A.; Ali S. Evaluation of antibacterial and catalytic potential of copper-doped chemically exfoliated boron nitride nanosheets. Ceram. Int. 2020, 46, 21073–21083. 10.1016/j.ceramint.2020.05.180. [DOI] [Google Scholar]
  42. Yang G.; Wu Y.; Zhu B.; Li J.; Fu Y.; Gao D.; Zhao J.; Ma S. Defect-related high temperature ferromagnetism in mechanically milled hexagonal boron nitride nanoplates. Appl. Surf. Sci. 2019, 487, 825–832. 10.1016/j.apsusc.2019.05.174. [DOI] [Google Scholar]
  43. Gonzalez Ortiz D.; Pochat-Bohatier C.; Cambedouzou J.; Bechelany M.; Miele P. Exfoliation of Hexagonal Boron Nitride (h-BN) in Liquide Phase by Ion Intercalation. Nanomaterials 2018, 8, 716. 10.3390/nano8090716. [DOI] [PMC free article] [PubMed] [Google Scholar]
  44. Bi Y.-S.; Liu B.; Liu X.-Y.; Qin Y.; Zou B.-X. A h-BCN for Electrochemical Sensor of Dopamine and Uric Acid. J. Nanomater. 2020, 2020, 1–9. 10.1155/2020/4604820. [DOI] [Google Scholar]

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