Growth of boron nitride nanotubes from magnesium-based catalysts

This study reports an efficient method for growing high-quality boron nitride nanotubes (BNNTs) via chemical vapor deposition of low-melting-point precursors—magnesium diboride (MgB₂), magnesium nitride (Mg₃N₂), and diboron trioxide (B₂O) at a growth temperature of 1000–1300 °C. The strong oxygen-capturing ability of Mg₃N₂ inhibits the formation of high-melting-point Mg₃B₂O₆, which helps MgB₂ to maintain an efficient and stable catalytic capacity, thereby enhancing its growth efficiency and utilization of the boron source. Moreover, polydimethylsiloxane (PDMS) composites formed from these BNNTs demonstrated much greater thermal conductivities than pure PDMS. Thus, this novel strategy for preparing BNNTs is efficient, and they have great potential for application as thermal interface materials.