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Synthesis of Highly Crystalline Multilayered Boron Niride Microflakes.

Ahmad P, Khandaker MU, Amin YM, Muhammad N - Sci Rep (2016)

Bottom Line: Boron niride microflakes of 2-5 μm in diameter and greater than 40 μm in length with multilayer structure and highly crystalline nature are synthesized in two states of catalysts and dual role of nitrogen at 1100 °C.Raman shift at 1370 (cm(-1)) and sharp peaks in the XRD pattern further confirm the h-BN phase and crystalline nature of the synthesized microflakes.Microflakes of h-BN with the above characteristics are highly desirable for the development of a solid state neutron detector with higher detection efficiency.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, Faculty of Science University of Malaya 50603 Kuala Lumpur Malaysia.

ABSTRACT
Boron niride microflakes of 2-5 μm in diameter and greater than 40 μm in length with multilayer structure and highly crystalline nature are synthesized in two states of catalysts and dual role of nitrogen at 1100 °C. Most of the microflakes are flat, smooth and vertically aligned with a wall-like view from the top. Transmission electron microscopy shows overlapped layers of microflakes with an interlayer spacing of 0.34 nm. The h-BN components of the synthesized microflakes are verified from B 1s and N1 s peaks at 190. 7 and 397.9 eV. Raman shift at 1370 (cm(-1)) and sharp peaks in the XRD pattern further confirm the h-BN phase and crystalline nature of the synthesized microflakes. Microflakes of h-BN with the above characteristics are highly desirable for the development of a solid state neutron detector with higher detection efficiency.

No MeSH data available.


Illustration of the chemical reactions occurred during the synthesis of BNMFs.
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f6: Illustration of the chemical reactions occurred during the synthesis of BNMFs.

Mentions: Formation of B2O2 is one of the basic product forms when MgO and γ-Fe2O3 are used as precursors with B. The formation of B2O2 is the initial step in the synthesis of h-BN products. For this purpose, MgO and γ-Fe2O3 work as catalysts with B. Both MgO and γ-Fe2O3 are effective producers of B2O2 and catalysts12. Thus MgO and γ-Fe2O3 not only work as catalysts with B to produce B2O2 but also produces Mg and Fe particles3. These catalysts have effective roles in the dissociation of molecular nitrogen and formation of BNMFs. The overall chemical reactions thus happened can be described in the following two stages, as shown in Fig. 6. In the 1st stage the precursors are heated up to 1100 °C in the presence of N2 atmosphere. During this stage, N2 works as an inert atmosphere inside the reaction chamber. During this stage the precursors synthesize B2O2 vapors and the metalic catalysts. The as-formed catalysts are adsorbed at the substrate surface whereas B2O2 remains suspended in the vapor form. Once the metalic catalysts are formed it changes the role of N2 in the further experiment. The as-formed catalysts dissociates the molecular nitrogen21 and includes it as a precursors in the next stage. In the 2nd stage, the dissociated nitrogen reacts with B from B2O2 and forms BNMFs whereas, the liberated oxygen from B2O2 is captured by the metalic catalysts and retain back its original form as it was first used in the reactant at the 1st stage.


Synthesis of Highly Crystalline Multilayered Boron Niride Microflakes.

Ahmad P, Khandaker MU, Amin YM, Muhammad N - Sci Rep (2016)

Illustration of the chemical reactions occurred during the synthesis of BNMFs.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4759817&req=5

f6: Illustration of the chemical reactions occurred during the synthesis of BNMFs.
Mentions: Formation of B2O2 is one of the basic product forms when MgO and γ-Fe2O3 are used as precursors with B. The formation of B2O2 is the initial step in the synthesis of h-BN products. For this purpose, MgO and γ-Fe2O3 work as catalysts with B. Both MgO and γ-Fe2O3 are effective producers of B2O2 and catalysts12. Thus MgO and γ-Fe2O3 not only work as catalysts with B to produce B2O2 but also produces Mg and Fe particles3. These catalysts have effective roles in the dissociation of molecular nitrogen and formation of BNMFs. The overall chemical reactions thus happened can be described in the following two stages, as shown in Fig. 6. In the 1st stage the precursors are heated up to 1100 °C in the presence of N2 atmosphere. During this stage, N2 works as an inert atmosphere inside the reaction chamber. During this stage the precursors synthesize B2O2 vapors and the metalic catalysts. The as-formed catalysts are adsorbed at the substrate surface whereas B2O2 remains suspended in the vapor form. Once the metalic catalysts are formed it changes the role of N2 in the further experiment. The as-formed catalysts dissociates the molecular nitrogen21 and includes it as a precursors in the next stage. In the 2nd stage, the dissociated nitrogen reacts with B from B2O2 and forms BNMFs whereas, the liberated oxygen from B2O2 is captured by the metalic catalysts and retain back its original form as it was first used in the reactant at the 1st stage.

Bottom Line: Boron niride microflakes of 2-5 μm in diameter and greater than 40 μm in length with multilayer structure and highly crystalline nature are synthesized in two states of catalysts and dual role of nitrogen at 1100 °C.Raman shift at 1370 (cm(-1)) and sharp peaks in the XRD pattern further confirm the h-BN phase and crystalline nature of the synthesized microflakes.Microflakes of h-BN with the above characteristics are highly desirable for the development of a solid state neutron detector with higher detection efficiency.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, Faculty of Science University of Malaya 50603 Kuala Lumpur Malaysia.

ABSTRACT
Boron niride microflakes of 2-5 μm in diameter and greater than 40 μm in length with multilayer structure and highly crystalline nature are synthesized in two states of catalysts and dual role of nitrogen at 1100 °C. Most of the microflakes are flat, smooth and vertically aligned with a wall-like view from the top. Transmission electron microscopy shows overlapped layers of microflakes with an interlayer spacing of 0.34 nm. The h-BN components of the synthesized microflakes are verified from B 1s and N1 s peaks at 190. 7 and 397.9 eV. Raman shift at 1370 (cm(-1)) and sharp peaks in the XRD pattern further confirm the h-BN phase and crystalline nature of the synthesized microflakes. Microflakes of h-BN with the above characteristics are highly desirable for the development of a solid state neutron detector with higher detection efficiency.

No MeSH data available.