Abstract: Structurally analogous to carbon nanotubes (CNTs), boron nitrogen nanotubes (BNNTs) exhibit high thermal conductivity while maintaining excellent electrical insulation. This dual functionality enables them to effectively address the key issues of efficient heat dissipation and electrical insulation in electronic devices. However, low production yields have hindered BNNTs’ research progress. In this work, we report a copper mesh-assisted laser ablation method for the high-yield synthesis of high-quality BNNTs. Small-diameter BNNTs (~8 nm) were produced at a record yield of nearly 336 mg/h-a 236 % improvement over conventional laser ablation. This yield enhancement is attributed to the catalytic effect of copper mesh, which facilitates the boron-nitrogen reaction efficiency without introducing metal impurities. As a demonstration for practical thermal management applications, poly(vinylidene fluoride)(PVDF)/BNNT(PBT) composite films were fabricated to further highlight the merits of the as-synthesized high-quality BNNTs. The PBT-50 film exhibits excellent flexibility, electrical insulation, and high thermal conductivity (3.22 W/(m K), an 18-fold increase over pure PVDF), which can effectively reduce the operating temperature of LEDs (15.49 and 3.68 °C lower than that of pure PVDF and PVDF/BN(PB)-50 film, respectively). These findings demonstrate BNNTs’ strong potential in advanced thermal management and insulation applications in flexible electronics and high-power systems, while their high-yield production will strongly facilitate their practical industrial applications.

Key words: Boron nitride nanotube, Laser ablation, Copper mesh, High yield, Thermal management