A simple co-doping strategy to synthesis of Ni@B/N carbon nanotubes with broadband and low-frequency electromagnetic wave absorption

Development of magnetic composites with rational microstructural design to achieve excellent electromagnetic wave (EMW) absorption in the low-frequency range is necessary and still challenging. Herein, the B/N carbon nanotubes loaded with Ni nanoparticles were successfully synthesized through a homogeneous precursor pyrolysis route. The homogeneity of the micro-magnetic field in the composite architecture is improved by the co-doping of B and N in carbon nanotubes due to the polarization effect, which would enhance the impedance matching and EMW absorption. The Ni@B/N carbon nanotubes exhibit a minimum reflection loss (RLmin) of −56.9 dB at 8.24 GHz with a maximum bandwidth of 7.12 GHz ranging almost all S and C bands (from 3.44 to 10.56 GHz) suggesting that the composite architecture effectively enhances low-frequency EMW absorption properties. The combination of impedance matching and interfacial polarization resulting from the homogeneous Ni nanoparticles and co-doping of B and N in carbon lattice structure is responsible for the enhanced low-frequency EMW absorption properties. This simple co-doping synthesis strategy provides a new design strategy for the preparation of broadband and low-frequency EMW absorbers.