Document Details
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Document Type |
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Thesis |
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Document Title |
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Optimization of nanosized material production via synthesis of transition metal Cr, Ni and Co borides إنتاج المواد متناهية الصغر من بوريدات عناصر الكروم والكوبلت والنيكل |
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Subject |
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Faculty of Sciences |
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Document Language |
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Arabic |
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Abstract |
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For the first time, synthetic comparison between the solid and liquid phases of metal borides is subjected to empirical investigation. The magnesiothermic reaction of MxOy, B2O3 and Mg yielded only M2O3. Similarly, direct reaction of MO3 or MCl3 with elemental boron yielded metal oxides. On the other hand direct reaction of Cr pure metal with elemental boron in 1:1, 1:2 and 1:3 ratios produced metal oxides except 1:3 ratio produced a mixture of M2B, M2O3 and MO3 (minimal oxides). Going down to the second and third rows of the transition metals MxO3 reacted directly with elemental boron in a muffle furnace at 500, 700 and 1000 °C for two, two and 15 hours, respectively yielding black beautiful nano crystals of M2B4, MB, MB2, MB4, M2B3, M2B and M2B5. The liquid phase reaction of metal chlorides, MxCly, with sodium borohydride, NaBH4, (excess) produced black nanocrystals and nanorods of MB, MB2, M4B3 and MB4. It was proven that oxidation state plays a great role in type of metal boride production. Reacting chromium trichloride (Cr III, d3 configuration) with sodium borohydride, NaBH4, in solution produced pure black nanocrystals and nanorods of Cr2B, while the reaction of chromium dichloride (Cr II, d4 configuration) with sodium borohydride, NaBH4, in solution produced a mixture of Cr2B and Cr2O3.
In addition to those reactions exceptional cases were recorded. CoCl2 with NaBH4 (solution phase) produced CoB2O4, in the meantime reaction of CoCl2 with B and Na (solid phase) produced same product. Reaction of elemental Cu and B (solid phase) produced Cu(BO2)2, and reaction of CuCl2 with NaBH4 (solution phase) produced CuB24.
In summary solid phase works fine with second and third rows of transition metals, while liquid phase works fine with first, second and third rows of transition metals. |
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Supervisor |
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Prof. Omar Ali Al-Zain |
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Thesis Type |
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Master Thesis |
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Publishing Year |
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1438 AH
2017 AD |
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Added Date |
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Wednesday, August 2, 2017 |
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Researchers
| ريم سليمان المسعودي | Al-masoudi, Reem Soliyman | Researcher | Master | |
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