scholarly journals Exfoliation of Hexagonal Boron Nitride (h-BN) in Liquide Phase by Ion Intercalation

Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 716 ◽  
Author(s):  
Danae Gonzalez Ortiz ◽  
Celine Pochat-Bohatier ◽  
Julien Cambedouzou ◽  
Mikhael Bechelany ◽  
Philippe Miele
Keyword(s):  
Aqueous Solution ◽  
Boron Nitride ◽  
Hexagonal Boron Nitride ◽  
X Ray Diffraction ◽  
Electronic Microscopy ◽  
X Ray ◽  
Boron Nitride Nanosheets ◽  
Green Approach ◽  
Step Procedure ◽  
Ion Intercalation

A green approach to prepare exfoliated hexagonal boron nitride nanosheets (h-BNNS) from commercially pristine h-BN involving a two-step procedure was investigated. 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 involves the removal of larger exfoliated h-BNNS through a centrifugation procedure. The exfoliation was caused not only by the sonication effect but also by intercalation of K+ and Zn2+ ions. Transmission electronic microscopy, X-ray diffraction and Raman spectroscopy techniques show that the obtained h-BNNS generally display a thickness of about a few (2–3) layers with an exfoliation efficiency as high as 16.3 ± 0.4%.

scholarly journals Catalyst-Free Bottom-Up Synthesis of Few-Layer Hexagonal Boron Nitride Nanosheets

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Shena M. Stanley ◽  
Amartya Chakrabarti ◽  
Joshua J. DeMuth ◽  
Vanessa E. Tempel ◽  
Narayan S. Hosmane
Keyword(s):  
Electron Microscopy ◽  
Boron Nitride ◽  
Hexagonal Boron Nitride ◽  
X Ray Diffraction ◽  
Bottom Up ◽  
X Ray ◽  
Boron Nitride Nanosheets ◽  
Catalyst Free ◽  
Transmission Electron ◽  
Novel Catalyst

A novel catalyst-free methodology has been developed to prepare few-layer hexagonal boron nitride nanosheets using a bottom-up process. Scanning electron microscopy and transmission electron microscopy (both high and low resolution) exhibit evidence of less than ten layers of nanosheets with uniform dimension. X-ray diffraction pattern and other additional characterization techniques prove crystallinity and purity of the product.

Boron Nitride Doped Polypyrrole Hybrid Composites for Photocatalytic Degradation of 2-Chlorophenol from Aqueous Solution

2020 ◽  
Vol 301 ◽  
pp. 145-152 ◽  
Author(s):  
Faizah Yunus ◽  
Muhammad Syazwan Kassim ◽  
Syed Shahabuddin ◽  
Nur Rahimah Said ◽  
Siti Nor Atika Baharin
Keyword(s):  
Aqueous Solution ◽  
Boron Nitride ◽  
Photocatalytic Degradation ◽  
Hybrid Composites ◽  
Hexagonal Boron Nitride ◽  
Solar Irradiation ◽  
X Ray Diffraction ◽  
Initial Concentration ◽  
Polymerization Method

This investigation focused on the photocatalytic degradation of o2-chlorophenol in aqueous solution by using hexagonal boron nitride (h-BN) doped polypyrrole (PPy) composite under solar irradiation. The composite was prepared via in-situ oxidation polymerization method using FeCl3 as oxidation agent. The synthesized h-BN/PPy composite were comprehensively characterized using x-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The photodegradation of 2-chlorophenol was performed under direct sunlight for 180 minutes with initial concentration (50-250 mg/L) and pH (3-9). h-BN/PPy composite efficiently degraded 2-chlorophenol (91.1%) with optimum conditions at pH 6 and 50 mg/L initial concentration compared to PPy and h-BN.

Effects of CaB2O4 Content on the Sintering Behavior of Hexagonal Boron Nitride

2011 ◽  
Vol 675-677 ◽  
pp. 131-134
Author(s):  
Yu Xia Cao ◽  
Ling Zhong Du ◽  
Wei Gang Zhang
Keyword(s):  
Boron Nitride ◽  
Diffraction Analysis ◽  
Apparent Density ◽  
Cross Sections ◽  
Hexagonal Boron Nitride ◽  
Sintering Behavior ◽  
Rockwell Hardness ◽  
X Ray Diffraction ◽  
X Ray ◽  
Grain Sizes

CaB2O4 was added into hexagonal boron nitride (hBN) to improve the sintering behaviors of hBN. CaB2O4 and hBN were mixed and then pressed into plates. The plates were sintered at 2000°C for 5h under a N2 ambience. The phase compositions with different CaB2O4 contents were examined with X-ray diffraction analysis. The fracture cross-sections of the hBN plates were investigated by SEM. The apparent density and Rockwell hardness were also measured. The results show that the hBN particles had a plate-like shape and the grain sizes of hBN increased with increasing CaB2O4 contents. The apparent density and Rockwell hardness decreased with increasing CaB2O4 contents. When the CaB2O4 content was 15(wt) %, the hBN has the average grain sizes of 3μm in diameter and 200nm in thickness, the apparent density of 1.06 g/cm3 and the Rockwell hardness of 3, respectively.

scholarly journals AB-stacked nanosheet-based hexagonal boron nitride

2021 ◽  
Vol 77 (2) ◽  
Author(s):  
Jae-Kap Lee ◽  
Jin-Gyu Kim ◽  
K. P. S. S. Hembram ◽  
Seunggun Yu ◽  
Sang-Gil Lee
Keyword(s):  
Boron Nitride ◽  
Hexagonal Boron Nitride ◽  
Metastable Phase ◽  
Stacking Sequence ◽  
Lateral Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Pressure High Temperature ◽  
Crystalline Growth

Hexagonal boron nitride (h-BN) has been generally interpreted as having an AA stacking sequence. Evidence is presented in this article indicating that typical commercial h-BN platelets (∼10–500 nm in thickness) exhibit stacks of parallel nanosheets (∼10 nm in thickness) predominantly in the AB sequence. The AB-stacked nanosheet occurs as a metastable phase of h-BN resulting from the preferred texture and lateral growth of armchair (110) planes. It appears as an independent nanosheet or unit for h-BN platelets. The analysis is supported by simulation of thin AB films (2–20 layers), which explains the unique X-ray diffraction pattern of h-BN. With this analysis and the role of pressure in commercial high-pressure high-temperature sintering (driving nucleation and parallelizing the in-plane crystalline growth of the nuclei), a growth mechanism is proposed for 2D h-BN (on a substrate) as `substrate-induced 2D growth', where the substrate plays the role of pressure.

scholarly journals Получение гетерогенных наночастиц Al/BN в микроволновой плазме

2020 ◽  
Vol 46 (10) ◽  
pp. 25
Author(s):  
Ш. Корте ◽  
М.К. Кутжанов ◽  
А.М. Ковальский ◽  
А.С. Конопацкий ◽  
Д.Г. Квашнин ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Boron Nitride ◽  
Microwave Plasma ◽  
Hexagonal Boron Nitride ◽  
Shear Stresses ◽  
X Ray Diffraction ◽  
Short Term ◽  
X Ray ◽  
Transmission Electron

In this work, the interaction of a mixture of Al and BN nanopowder with hydrogen microwave plasma was studied. Using X-ray diffraction analysis, scanning and transmission electron microscopy, the formation of AlN and AlB2 nanocrystals as a result of short-term (~ 30 ms) interaction of Al vapor with h-BN was established. Obtained results also indicate the formation of hydrogenated hexagonal boron nitride h-BN-H. The critical shear stresses were calculated for the interfaces between BN and Al, AlB2, and AlN. Approaches for increasing the strength of the composite materials based on hexagonal boron nitride and aluminum are discussed.

scholarly journals High-Yield Synthesis of Zinc Oxide Nanoparticles from Bicontinuous Microemulsions

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
S. López-Cuenca ◽  
L. A. Pérez Carrillo ◽  
M. Rabelero Velasco ◽  
R. Díaz de León ◽  
H. Saade ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Zinc Oxide ◽  
Zno Nanoparticles ◽  
Zinc Oxide Nanoparticles ◽  
High Yield ◽  
Oxide Nanoparticles ◽  
X Ray Diffraction ◽  
Electronic Microscopy ◽  
X Ray ◽  
Hydrolysis Of

The high-yield synthesis of zinc oxide (ZnO) primary nanoparticles with high purity and with diameters between 6 and 22 nm using bicontinuous microemulsions is reported in this work. The ZnO nanoparticles were made by hydrolysis of Zn(NO3)2with NaOH aqueous solution and precipitation, followed by calcination of the precipitate. Higher yields and productivities of ZnO nanoparticles were obtained compared to values produced with w/o micremulsions reported in the literature. Particles were characterized by transmission electronic microscopy (TEM), X-ray diffraction, and atomic absorption spectroscopy.

Preparation of n-type polyaniline/hexagonal boron nitride composites with a large thermoelectric power factor

2021 ◽  
pp. 096739112110425
Author(s):  
Volkan Ugraskan ◽  
Ebubekir Ceran ◽  
Ozlem Yazici
Keyword(s):  
Boron Nitride ◽  
Power Factor ◽  
Hexagonal Boron Nitride ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
X Ray Diffraction ◽  
Thermoelectric Power Factor ◽  
X Ray ◽  
Seebeck Coefficients ◽  
Vis Spectroscopy

In the present study, it was aimed to investigate the thermoelectric (TE) properties of polyaniline/hexagonal boron nitride (PANI/h-BN) composites. First, h-BN was synthesized from boric acid and urea. Then, PANI-HCl was synthesized by oxidative chemical polymerization. Finally, the composites were prepared using different weight ratios of h-BN. The composites were characterized using attenuated total reflection accessory attached Fourier-transform infrared spectroscopy, UV-vis spectroscopy, X-ray diffraction, and scanning electron microscopy/energy dispersive X-ray analyzer. TE investigation of the composites showed that the addition of h-BN significantly contributes to the TE properties of PANI-HCl. The addition of h-BN increased the power factor of PANI-HCl from 0.07 μWm−1K−2 to 143.05 μWm−1K−2. Furthermore, all the composites showed negative Seebeck coefficients which are the characteristics of n-type semiconductors.

Microstructure and Chemical Composition of Boron Nitride Fibers

2013 ◽  
Vol 591 ◽  
pp. 16-19 ◽  
Author(s):  
Ru Li ◽  
Chuan Shan Li ◽  
Jie Tang ◽  
Jian Xin Tang ◽  
Xiao Yong Du ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Boron Nitride ◽  
Photoelectron Spectroscopy ◽  
Hexagonal Boron Nitride ◽  
Energy Dispersive Spectrum ◽  
Test Method ◽  
Ir Absorption ◽  
X Ray Diffraction ◽  
Modified Technique ◽  
X Ray

Boron nitride(BN) fibres were synthesized by modified technique of Economy’s method. The products were characterized by X-ray diffraction (XRD), fourier transform infrared (FT-IR) absorption spectroscopy, field-emission scanning electron microscopy (FE-SEM), X-ray energy dispersive spectrum (EDS) and X-ray photoelectron spectroscopy (XPS). The results showed that BN fibers were mainly hexagonal boron nitride (h-BN) with diameters of 5-8 μm and the major compositions of BN fibers are B and N with a very small amount of O and C. At last, the chemical composition of samples were determined by the chemical analysis test method like GB/T 16555-2008 and GJB 507-1998.

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