Jornal de Nanomedicina e Nanotecnologia

Abstrato

Different Synthetic Routes of Group Six (VIB) Nano-Metal Borides

Al-Zain OA and Al-Masoudi RS

For the first time, the synthetic comparison between the solid and liquid phases of metal borides was subjected to empirical investigation. The magnesiothermic reaction of CrO₃, B₂O₃, and Mg yielded the only C₂rO₃. Similarly, the direct reaction of CrO₃ or CrCl₃ with elemental boron yielded chromium oxides. On the other hand, direct reaction of pure Cr metal with elemental boron in 1:1, 1:2 and 1:3 ratios, showed that only 1:3 ratio, produced a mixture of Cr₂B, Cr₂O₃, and CrO₃ (minimal oxides). Going down group six, (VIB) MoO₃ and WO₃, reacted directly with elemental boron in a muffle furnace at 500, 700 and 1000°C for 2, 2 and 15 hours respectively, yielding black beautiful nanocrystals of Mo₂B₄, MoB, WB₄, and W₂B₅. The liquid phase reaction of molybdenum pentachloride, MoCl₅, with sodium borohydride, NaBH₄ (1:5 ratio), produced black nanocrystals and nanorods of MoB and MoB₄. Reacting chromium trichloride with sodium borohydride, NaBH4 (1:3 ratio), in solution, produced pure black nanocrystals and nanorods of Cr2B, while the reaction of chromium dichloride with sodium borohydride, NaBH₄ (1:2 ratio), in solution, produced a mixture of Cr₂B and Cr₂O₃.