This work introduces a high-performance absorber based on a lightweight composite material of corn straw biochar and magnetic cobalt nickel zinc ferrite. A composite absorber of corn straw biochar with hierarchical pore structure and magnetic zinc cobalt nickel ferrite particles (Ni–Co–Zn ferrite/C) was prepared by a simple two-step approach of carbonization followed by in-situ growth method. The morphology, structure, function, and absorbing properties of the prepared samples were characterized, and RCS simulation was performed. The results show that the optimal reflection loss value of Ni–Co–Zn ferrite/C-2 reaches −38.04 dB when the layer thickness is 3.5 mm, and the effective absorption bandwidth is 4.32 GHz. The potential of Ni–Co–Zn ferrite/C-2 composite material in stealth applications is verified. It is mainly attributed to the excellent impedance matching performance caused by the multi-level pore structure and the strong polarization loss caused by the rich heterogeneous interface and active sites, which plays a key role in the attenuation of electromagnetic waves. This study provides a useful reference for the design of magnetic ferrite particles/metal oxides/biomass-derived carbon microwave absorbing materials with hierarchical porous structure characteristics.

In situ co-deposition-enabled hierarchical pores in Ni–Co–Zn ferritecarbon derived from biomass composites with adaptive electromagnetic wave absorption
    Abstract
    1 Introduction
    2 Materials and methods
        2.1 Materials
        2.2 Preparation of biomass-derived carbon from corn stalk
        2.3 Preparation of NCZFOCCS composite
        2.4 Characterization
    3 Results and discussion
    4 Conclusion
    Acknowledgements 
    References

• Guoliang Chen(College of Environmental and Chemical Engineering, Shenyang Ligong University, Shenyang 110159, People’s Republic of China) Corresponding author
• Dan Feng(College of Science, Shenyang Ligong University, Shenyang 110159, People’s Republic of China)
• Runqing Liu(College of Materials Science and Engineering, Shenyang Ligong University, Shenyang 110159, People’s Republic of China)