Ti3C2Tx MXene Nanosheet/Metal–Organic Framework Composites for Microwave Absorption

High-performance absorbers with laminated and three-dimensional structures for abundant interfaces can improve electromagnetic wave absorption property obviously. Meanwhile, the combination and dispersion of components have a positive effect on the microwave absorption (MA) property for excellent absorption bandwidth. Herein, accordion-like MXene/Co-ZIF and MXene/Ni-ZIF composites were synthesized by electrostatic self-assembly between MXene and metal–organic frameworks (Co-MOF and Ni-MOF) and then pyrolyzed in the H2/Ar mixed atmosphere (Co-MOF and Ni-MOF named as Co-ZIF and Ni-ZIF, respectively, after pyrolysis). The MXene/Co-CZIF 50% composites displayed good absorption performance with the optimal RL value of −60.09 dB at 7.36 GHz and the broadened absorption bandwidth 9.3 GHz (RL < −10 dB). MXene/Ni-CZIF 50% exhibited promising performance with the RL value measured up to −64.11 dB at 5.12 GHz, and possessed the ultrabroad effective response bandwidth of 4.56 GHz (RL < −10 dB). Furthermore, a unique accordion-like structure, magnetic–dielectric synergistic, multiple interface scatterings and reflections, and dipole polarization were said to improve MA properties. This study provided a method for the synthesis of absorbers with tunable electromagnetic properties and wide absorption bandwidth of MXene-based composites.