Facile synthesis of sandwich-like heterogeneous Ti3C2Tx/TiO2/Fe3O4/Fe for strong and broadband microwave absorption by magnetic-dielectric synergy

Developing a lightweight microwave absorbing materials with high absorption capacity and wide absorption bandwidth at low thickness is a perennial challenge in practical applications in the microwave absorption (MA) field. Herein, sandwich-like heterogeneous Ti3C2Tx/TiO2/Fe3O4/Fe are designed by synergistically incorporating dielectric-magnetic components with a simple solvothermal method and post-annealing. The sandwich-like heterogeneous interface produces sufficient conduction loss for Ti3C2Tx/TiO2/Fe3O4/Fe, with TiO2 crystals and amorphous carbon anchored on its surface to enhance interface polarization and Debye relaxation. Additionally, the presence of Fe nanoparticles induces magnetic loss, including natural resonance and eddy current loss. By bidirectionally regulating the ratio of Ti3C2Tx and Fe3O4, the minimum reflection loss (RLmin) value reaches - 64.6 dB at 17.49 GHz with a 1.48 mm thickness, and the corresponding effective absorption bandwidth (EAB, RL < -10 dB) is 4.59 GHz (13.41-18 GHz). The results suggest that the exceptional EMW absorption performance of composites can be attributed to the dielectric-magnetic synergistic effect and sandwich-like heterostructures. This study offers a rational approach for synthesizing ultrathin and lightweight Ti3C2Tx-based absorbers.