J. Mater. Sci. Technol. ›› 2026, Vol. 244: 196-207.DOI: 10.1016/j.jmst.2025.04.043

• Research Article • Previous Articles     Next Articles

Hierarchically pepper wood-like Co3Fe7@C nanotubes for broadband microwave absorption and efficient electromagnetic interference shielding

Baolei Wanga,*, Cui Nib, Meichun Dinga, Demin Zhaoa, Zhenying Duana, Xiubo Xieb,*, Chenwei Lia,*   

  1. aSchool of Chemistry and Pharmaceutical Engineering, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian 250102, China;
    bSchool of Environmental and Material Engineering, Yantai University, Yantai 264005, China
  • Received:2025-02-21 Revised:2025-03-31 Accepted:2025-04-01 Published:2026-02-10 Online:2025-06-03
  • Contact: *E-mail addresses: blwang@sdfmu.edu.cn (B. Wang), xiuboxie@ytu.edu.cn (X. Xie), lichenwei@iccas.ac.cn (C. Li)

Abstract: Nowadays, the increasingly serious electromagnetic wave (EMW) pollution and electromagnetic interference (EMI) problems urgently require the development of high-performance electromagnetic attenuation (EMA) materials with tunable green low-reflective EMI shielding and efficient EMW absorption properties. Herein, the pepper wood-like Co3Fe7@C nanotubes were constructed by a combined strategy of metal chelates derivatization, self-polymerization, and in-situ carbon reduction, composed of magnetic alloys Co3Fe7 nanoparticles (size of 7.5 nm) densely embedded in carbon nanotubes. The EMW absorption and EMI shielding capabilities of the samples with different filling ratios were investigated. Benefiting from the synergistic attenuation mechanism provided by the hollow tubular structure and strong magnetic/dielectric components, the Co3Fe7@C nanotubes with protrusions on the surface displayed superior EMW absorption performances at extremely low filling ratio (5 wt.%) with a minimum reflection loss (RLmin) of -107.4 dB and an effective absorption bandwidth (EAB) of 11.6 GHz. Notably, the EMI shielding effectiveness of the optimized sample reaches up to 44.94 dB, while the effective absorption efficiency of the samples with filler loading over 15 wt.% is over 90%. Furthermore, the composite with a coating thickness of 2.0 mm also exhibits an ideal radar cross-sectional (RCS) reduction of 21.2 dB m2 at 0°. This study provides unique insights into the design and synthesis of high-efficiency EMA materials, and the Co3Fe7@C nanotubes are expected to be practically applicable in complex environments.

Key words: Co3Fe7@C nanotubes, EMW absorption, Electromagnetic interference shielding, Radar cross-section