Synthesis of high-performance boron carbon nitride nanotube/Ni microwave absorber featuring in-situ formed heterostructure

By utilizing a molecular-scale precursor engineering strategy, Ni nanoparticle-embedded boron carbon nitride nanotube heterostructures (BCNNT/Ni) were successfully constructed through polyethylene glycol-mediated spatial confinement pyrolysis. The precisely controlled thermal delamination process enables atomic-level architectural precision in creating gradient dielectric-magnetic heterointerfaces with tunable impedance matching characteristics. The experimental results demonstrate that the fabricated BCNNT/Ni nanocomposites display outstanding electromagnetic wave (EMW) absorption capabilities, especially within the high-frequency range. Through modulating the Ni proportion, BCNNT/Ni exhibits a minimum reflection loss of −50.82 dB at a frequency of 16.3 GHz, a thickness of merely 2.0 mm, and an effective absorption bandwidth of 6.12 GHz. The BCNNT/Ni nanocomposite prepared by this facile and low-cost pyrolysis method shows a broad application prospect in the EMW absorption field through multi-scale interfacial polarization and synergistic dielectric-magnetic coupling mechanisms.