High-efficiency tunable microwave absorption in N–CNF@MXene@MoS2 aerogel with island-chain structured MXene and multiple heterogeneous interfaces

Research on developing highly efficient microwave absorption (MA) absorbers is crucial for addressing electromagnetic (EM) pollution and advancing stealth technology. MXene, a new class of MA materials, have been widely studied. Nevertheless, MXene often faces challenges such as high self-stacking and excessive electrical conductivity, which lead to poor impedance matching. To overcome these problems, the unique manufacturing produces an overall homogeneous and locally aggregated MXene in the form of island chains, enhancing electrical conductivity and polarization loss while alleviating the self-stacking problem of MXene nanosheets. Further improvement is achieved by modifying the N–CNF@MXene aerogel with MoS₂ through atomic layer deposition (ALD). This modification resulted in a layered core-sheath structure featuring the N–CNF@MXene@MoS₂ aerogel (NCMMA) absorber. Importantly, this process preserved the intrinsic structure of the material while significantly enhancing its MA performance. NCMMA has a minimum reflection loss RL_min of −78.32 dB (3.49 mm) with a fill factor of only 3.97 %. The effective absorption bandwidth (EAB) is 7.58 GHz (2.5 mm), covering the Ku band. The unique joint process design of hierarchical core-sheath in situ heterogeneous interfaces combined with the complex interpenetrating conductive network structure employed in this work is a strong candidate for MA materials for next-generation lightweight stealth coatings.