2D Ti3C2T MXene/MOFs composites derived CoNi bimetallic nanoparticles for enhanced microwave absorption

The emerging two-dimensional (2D) transition metal carbide (MXene) has been a hot topic due to its special structure and high dielectric loss. However, the inevitable stacking phenomenon and lack of magnetic loss of the related MXene materials seriously restrict their application in electromagnetic (EM) absorption. Herein, Ti3C2Tx (a typical material of MXene family) modified with metal–organic frameworks (MOFs) is prepared via simple electrostatic self-assembly and consequent heat treatment. The lamellar MXene provided the substrate for anchoring the MOFs, and the Ni nanoparticles catalytically derived carbon nanofibers (CNFs) served as bridges to construct the cross-linked network. Based on this network structure, the extensive heterogeneous interfaces effectively facilitate the dielectric loss ability, and the addition of magnetic CoNi nanoparticles can enhance the additional magnetic loss capacity. It is worth noting that when the matching thickness is only 1.76 mm, the minimum reflection loss (RLmin) value of the sample (Ti3C2Tx/CNFs/TiO2/CoNi) reaches –54.6 dB, and the corresponding effective absorption bandwidth (EAB, RL < –10 dB) is 4.0 GHz (11.9–15.9 GHz). These results show that magnetic-dielectric synergistic, interfacial polarization, and multilayer structure, were conducive to the improvement of microwave absorption (MA) properties. This study envisions a novel strategy for constructing efficient MXene-based microwave absorbers.