Self-Assembly-Magnetized MXene Avoid Dual-Agglomeration with Enhanced Interfaces for Strong Microwave Absorption through a Tunable Electromagnetic Property

Multilayered microwave absorbers which can provide massive interfaces are highly needed for electromagnetic-wave absorption property enhancement. Meanwhile, how to effectively avoid agglomeration and further widen the absorption band is still a challenge. Herein, accordion-like magnetized MXene/Ni composites were fabricated by the electrostatic self-assembly interaction between multilayer MXene and Ni­(OH)2 nanoplates and subsequent in situ reduction in the H2/Ar atmosphere. Ni nanoparticles were uniformly distributed without magnetic agglomeration between the multilayered gaps of the adjacent 2D (2 dimension) MXene (Ti3C2T x ) of MXene/Ni nanocomposites (magnetized MXene), which hold the distinct absorption performance that the reflection loss maximum measures up to −50.5 dB at 5.5 GHz. Moreover, dynamic magnetic response of the magnetized MXene absorber was first researched by the electron holography analysis. The related key mechanism includes the enhanced magnetic loss, less dual-agglomeration (multilayer MXene itself and magnetic agglomeration), and more interfaces and intrinsic defects for related polarization. A broadened absorption bandwidth can further be obtained by changing the mass ratio of MXene to Ni that possesses the widest absorption bandwidth of 5.28 GHz. This work provides a new route for the balance among strong absorption intensity, tunable electromagnetic properties, and wide absorption bandwidth of the MXene-based nanocomposites.