Multifunctional and magnetic MXene composite aerogels for electromagnetic interference shielding with low reflectivity

Lightweight and multifunctional compressible aerogels with low reflectivity are highly demanded to protect electronic devices from increasingly serious electromagnetic interference and radiation. Although simply incorporating magnetic particles can reduce the strong electromagnetic (EM) reflection caused by the high conductivity of MXene, high density, inhomogeneous dispersion and weak interfacial interactions may impede the potential applications. Here, we report the fabrication of three-dimensional magnetic MXene/Fe3O4@acidified-MWCNT (aMWCNT) composite aerogel by a directional freezing and subsequent freeze-drying process, and the shielding effectiveness of composite aerogel can be tuned from 32.5 to 51.6 dB in the X-band. At the same time, since the Fe3O4 nanoparticles are pre-decorated onto aMWCNTs, the heterogeneous interface polarization and magnetic loss are enhanced at low loadings. Therefore, the reflected power coefficient of the aerogel is as low as 0.31 with an ultra-light density of only 10 mg cm-3. Moreover, the good reversible compressibility, fatigue resistance, excellent heat insulation, and infrared stealth grant the aerogels great application prospects for antiinfrared detection and green shielding materials.