In situ construction of Co@nitrogen-doped carbon/Ni nanocomposite for broadband electromagnetic wave absorption

The tunable multicomponent synergistic loss mechanism and multiple heterogeneous interfaces of magnetic carbon-based composites have emerged as the efficient electromagnetic wave absorbing (EMWA) materials. Herein, the Ni(OH)2/ZIF-67 precursors were synthesized via the hydrothermal and liquid-phase deposition methods, and then carbonized at different temperature under N2 atmosphere to obtain Co@nitrogen-doped carbon/Ni (Co@NC/Ni) nanocomposites. The metallic components with good dispersion property provided magnetic loss and improved impedance matching. Meanwhile, they also acted as catalysts to induce the formation of graphitized carbon, enhancing the conductive loss. Furthermore, more heterogeneous interfaces and defects were generated inside the sample, which promotes dielectric loss. Therefore, the Co@NC/Ni nanocomposite (carbonized at 600 degrees C) exhibited excellent EMWA performance with a minimum reflection loss (RL) of -47.10 dB, and the effective absorption bandwidth (RL & LE; -10 dB) can reach 6.84 GHz at 2.5 mm with a filling ratio of 30%. This work provides a heterogeneous interface construction strategy for the future application of high-performance magnetic carbon based EMWA materials.

Automated summary

The Co@nitrogen-doped carbon/Ni (Co@NC/Ni) nanocomposites were synthesized by hydrothermal and liquid-phase deposition methods, and then carbonized at different temperatures under N2 atmosphere. The tunable multicomponent synergistic loss mechanism and multiple heterogeneous interfaces of these composites make them efficient electromagnetic wave absorbing materials. The metallic components provide magnetic loss and improved impedance matching, while also acting as catalysts to induce the formation of graphitized carbon and enhancing conductive loss. In addition, more heterogeneous interfaces and defects were generated inside the sample, promoting dielectric loss. The Co@NC/Ni nanocomposite carbonized at 600 degrees C exhibited excellent electromagnetic wave absorbing performance, with a minimum reflection loss of -47.10 dB and an effective absorption bandwidth of 6.84 GHz at 2.5 mm with a filling ratio of 30%. This study provides a strategy of heterogeneous interface construction for future application of high-performance magnetic carbon-based electromagnetic wave absorbing materials.