Double-layered chitosan aerogel/MXene film composites with asymmetric structure for absorption-dominated electromagnetic interference shielding and solar-driven interfacial evaporation

Aerogel/film composites with asymmetric structures have outstanding potential for multifunctional applications of absorption-dominated electromagnetic interference (EMI) shielding and solar-driven interfacial evaporation. In this work, the double-layered aerogel/film composites are fabricated by stacking magnetic multi-walled carbon nanotubes/chitosan (mMWCNTs/CS) aerogel and MXene/carboxylated styrene-butadiene rubber (MXene/XSBR) film together under the electrostatic interaction and hydrogen bonds. Profiting from the integration of porous mMWCNTs/CS aerogel as an adsorption layer and dense MXene/XSBR film as a reflection layer, the resulting aerogel/film composites achieve a high absorption coefficient (A) of 0.76 and an optimum EMI shielding effectiveness (SE) of 86.32 dB via the absorption-reflection-reabsorption process. Furthermore, the resulting aerogel/film composites possessing high sunlight adsorption capability (>96.2%) exhibit an excellent solar-driven evaporation rate of up to 2.44 kg∙m^-2∙h^-1 with a notable photothermal conversation efficiency of 92.2% under 1 sun irradiation. The mMWCNTs/CS-MXene/XSBR aerogel/film composites with asymmetric structures not only provide an efficient strategy for developing absorption-dominated EMI shielding materials but also extend a novel path for the practical application of solar evaporation systems.