Facile fabrication of boron and nitrogen co-doped carbon@Fe₂O₃/Fe₃C/Fe nanoparticle decorated carbon nanotubes three-dimensional structure with excellent microwave absorption properties

Herein, we report a facile process to massively synthesize three-dimensional (3D) boron and nitrogen co-doped carbon@Fe₂O₃/Fe₃C/Fe nanoparticle decorated carbon nanotubes (B/N co-doped C@Fe₂O₃/Fe₃C/Fe-CNTs). The fabrication involved a simple one-step chemical vapor deposition process. These as-synthesized 3D B/N co-doped C@Fe₂O₃/Fe₃C/Fe-CNTs based absorbers exhibited excellent microwave absorption properties with tunable strong absorption wavebands in the frequency range of 2–18 GHz. A minimum reflection loss (RL) value of −42.6 dB was observed at 6.88 GHz with absorber thickness of 3.5 mm. Moreover, the absorption bandwidth for RL less than −10 dB was as large as 4.14 GHz when the absorber thickness dropped to 2.0 mm. A possible absorption mechanism was proposed in detail, which can be attributed to the synergy of the impedance matching and enhancement of multiple reflection among 3D B/N co-doped C@Fe₂O₃/Fe₃C/Fe nanoparticles.