Transition metal carbides and nitrides (MXenes) have demonstrated high potential for developing thin, flexible, and high-performance electromagnetic interference (EMI) shields. These materials also present significant challenges, including susceptibility to oxidation, difficulty achieving strong interfacial interactions, and the complexity of fabricating ultrathin yet tough macrostructures. Here, aramid nanofibers (ANFs) are employed to enable both physical and chemical dual cross-linking of MXene nanosheets (C-ANF/C-MXene) with mussel byssus-inspired microstructure. The large-scale, flexible, and highly conductive C-ANF/C-MXene films are produced through the ambient pressure casting appraoch, underlined as an energy-efficient and scalable solution. Compared to ANF/MXene films created solely through the physical cross-linking, C-ANF/C-MXene films exhibit notable enhancements in mechanical strength, toughness, hydrophobicity, water resistance, and oxidation stability while maintaining their exceptional EMI shielding performance. The combination of MXene, ANF, and a layered microstructure synergistically boosts the EMI shielding performance alongside remarkable photo-/electro-thermal conversion. This work underscores the potential of a novel type of multifunctional MXene-based film for applications in flexible electronics, electromagnetic protection or compatibility, and thermal therapy.

A novel type of three-dimensional ultralight aerogel sphere, consisting of one-dimensional nanocellulose-derived carbon fibers and two-dimensional graphene layers, was prepared based on a developed drop-freeze-drying followed by carbonization approach. The nanofibrous carbon efficiently prevents the agglomeration of the graphene layers, which, in turn, reduces the shrinkage and maintains the structural stability of the hybrid carbon aerogel spheres. Consequently, the aerogel spheres showing an ultralow-density of 2.8 mg/cm³ and a porosity of 99.98% accomplish the tunable dielectric property and electromagnetic wave (EMW) absorption performance. The high-efficiency utilization of biomass-derived fibrous nanocarbon, graphene, and the porous structure of the hybrid aerogel spheres leads to the excellent EMW absorption performance. The aerogel spheres display an effective absorption bandwidth of 6.16 GHz and a minimum reflection loss of −70.44 dB even at a filler loading of merely 3 wt.%, significantly outperforming that of other biomass-derived carbon-based EMW absorbing materials. This work offers a feasible, facile, and scalable approach for fabricating high-performance and sustainable biomass-based aerogels, suggesting a tremendous application potential in EMW absorption and aerospace.