Nanostructures of boron nitride (BN) including nanotubes, nanofibers and nanosheets having a large surface area are very useful in storing hydrogen and other gases. In the present paper we report the synthesis and characterization of these nanostructures of BN using mechanothermal process. Under this process elemental boron powder is first ball milled to about 50 h in an inert atmosphere and then annealed at 1100℃ - 1250℃ for 6 h in the presence of NH3 gas. By this treatment nanotubes and other nanostructures of BN were synthesized. The diameter of BN nanotubes varied from 20 to 50 nm and most of them exhibited spindle or bamboo like morphology. Because of the large surface area, these nanotubes may be explored for a better hydrogen gas storage device as compared to the crystallized nanotubes. The main advantage of this technique is that the nanotubes can be grown in large quantity. A possible growth mechanism towards the evolution of such fascinating nano-objects of boron nitride has been discussed employing high-resolution transmission electron microscopy and photoluminescence.
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