Surface modification to test “gaseous model” for BN nanotubes formation under the concentrated light and its application for graphene

•Heating of modified by acid and alkali initial powder results in formation of bubbles.•Alkali modification has displayed the appearance of open-cell-structured BN foam.•Modification of initial h-BN powder decreases probability of BN nanotubes formation.•Evolution of a bubble in “gaseous theory” explains nanotubes and graphene formation.

Based on the previous research results on formation of BN whiskers and nanotubes in process of initial h-BN powder transformation under the effect of concentrated light radiation in an optical furnace and nitrogen flow, surface modification of initial h-BN was made. KOH, HCl, H2SO4, acetone and alcohol were chosen for surface modification to obtain new structures. It was demonstrated that KOH, HCl, H2SO4 purify h-BN from oxygen contamination, acetone and alcohol do not effect at all. SEM and TEM investigations have shown preferential formation of two dimensional (2D) BN nanostructures and some of 1D nanostructures along with equiaxed or platelet nanostructures due to presence of H2O. The growth of the bubbles on the surface of BN sample has confirmed the “gaseous model” based on evolution of the bubble developed for nanotubes formation. Burst of these bubbles results in graphene-like structures formation. The stepwise transformation of bubbles of proper chemical composition leads to threads formation because of their pulling of heated gases upwards.

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