Multi-interface engineering of hierarchical carbon foam decorated with bimetallic selenides for enhanced microwave absorption and thermal insulation

The proliferation of wireless technologies has rendered electromagnetic wave pollution a critical concern, driving the demand for lightweight absorbers with broad bandwidth and strong attenuation. However, achieving a balance between impedance matching and loss capacity remains challenging, especially at low filler loadings. Herein, a multi-interface engineering strategy is reported to construct an ultralight hierarchical carbon foam decorated with bimetallic selenides (CoSe 2 /MnSe/C@MC, denoted CMCM). This architecture is fabricated via in-situ growth of bimetallic CoMn-ZIFs on carboxymethyl cellulose-modified melamine foam, followed by carbonization and selenization. The three-dimensional porous framework provides excellent impedance matching and multiple scattering, while the synergistic effects of interfacial polarization, dipolar polarization, and conductive loss enhance microwave attenuation. The optimized foam achieves a minimum reflection loss of −63.91 dB at a thickness of 1.43 mm and an effective absorption bandwidth of 4.72 GHz at 1.41 mm. Additionally, the lightweight foam exhibits favorable thermal insulation capability. This work establishes a versatile multi-interface engineering paradigm for designing lightweight, broadband, and multifunctional electromagnetic wave absorbers. Download: Download high-res image (349KB) Download: Download full-size image