Fe/Fe3O4/biomass carbon derived from agaric to achieve high-performance microwave absorption

• Published in: Diamond and related materials 2022-11, Vol.129, p.109386, Article 109386
• Main Authors: Su, Jinbu, Yang, Rui, Zhang, Pengkui, Wang, Boli, Zhao, Heng, Zhang, Wenhe, Wang, Weike, Wang, Chengbing
• Format: Article
• Language: English
• Subjects: Biomass; Biomass agarics; Carbon; Carbonization; Composite materials; Dielectric loss; Dipoles; Electromagnetic radiation; Electromagnetic wave absorption; Fe/Fe3O4/BC composites; Ferric nitrate; Impedance matching; Iron oxides; Microwave absorbers; Microwave absorption; Nanoparticles; Polarization; Precursors; Superhigh frequencies; Synergistic effect
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/j.diamond.2022.109386

Recently, biomass carbon materials as electromagnetic wave-absorbing materials have received widespread attention due to their easy availability, low cost, and environmental friendliness. However, for the vast majority of microwave absorbing materials that possess only dielectric losses, it is difficult for them to achieve satisfactory microwave absorbing performance. This paper proposes a new strategy to prepare a magnetic biomass composite material with tunable high-performance microwave absorption using agaric as the biomass carbon precursor and ferric nitrate as the magnetic precursor. When the carbonization temperature is 800 °C, the Fe/Fe3O4/biomass carbon (Fe/Fe3O4/BC) composite exhibits excellent microwave absorption performance in the X-band. At a thickness of 2.06 mm and a frequency of 9.63 GHz, its minimum reflection loss reaches −30.41 dB, and the effective absorption bandwidth is 2.45 GHz. In the carbonization process, ferric nitrate is transformed into magnetic Fe3O4 and Fe nanoparticles. The magnetic losses generated by Fe/Fe3O4 and the dielectric losses of biomass carbon, interfacial polarization, dipole polarization and multiple reflection synergies improve the impedance matching characteristics of the composite and improve the microwave absorption performance. Therefore, the prepared Fe/Fe3O4/BC composite material has exhibits great potential as a high-efficiency microwave absorber. [Display omitted] •Fe/Fe3O4/BC composites were prepared by a simple direct carbonization method.•Biomass carbon source agaric has the characteristics of wide source, low price and good structural stability.•The preparation process of the Fe/Fe3O4/BC composites is simple and can be produced in large quantities.•The Fe/Fe3O4/BC composites exhibit excellent microwave absorption properties in the X-band.