Engineering fragmented MXene-derived localized conductive networks in multifunctional cellulose composite aerogel absorbers

The advancement of modern science and technology has significantly facilitated daily life and societal operations, yet simultaneously contributes to increasing electromagnetic pollution. Cellulose aerogels have shown broad application prospects for electromagnetic wave absorption (EMWA) due to their low density, high porosity, and adjustable structure. In this work, we first obtained fragmented MXene by ultrasonic treatment of flake MXene, and combined it with carboxymethyl cellulose (CMC) to prepare a functional cellulose-based composite aerogel absorber via a straightforward freeze-drying technology. Thanks to the rich surface functional groups of MXene fragments, they could be efficiently attached to the surface of the aerogel skeleton, thus giving the composite aerogel excellent EMWA performance. At an ultrathin matching thickness of 1.52 mm, the absorber achieved highly efficient microwave attenuation with minimum reflection loss of −49.3 dB and effective absorption bandwidth of 4.89 GHz. In addition, the unique porous structure of the composite aerogel endowed it with exceptional thermal insulation and sound absorption capabilities. This work presents a simple and sustainable strategy to develop multifunctional cellulose composite materials for a variety of application scenarios.