Constructing broadband microwave metastructure absorber based on 2D Ti3CNTx MXene magnetic composites

Microwave absorbing materials (MAMs) have been used to address electromagnetic pollution for both civil and military applications, and MAMs with broadband microwave absorption still remain a challenge. The microwave absorption performance of Ti3CNTx MXene is poor due to impedance mismatch. Modification of Ti3CNTx with magnetic materials is an effective way to improve the impedance matching and increase the effective absorption bandwidth (EAB). Here, 2D Ti3CNTx based magnetic composites were successfully prepared by an electrostatic self-assembly method. The microwave absorption properties of the composites were investigated by varying the loading of Ti3CNTx in the composites and the filling ratio of the composites in the absorber. The EAB can reach 4.75 GHz with an absorber thickness of only 1.32 mm. Integrated with a macroscale multilayer periodic gradient design, the FCM (Fe@NC/Ti3CNTx) composites based metastructure exhibits broadband microwave absorption with an EAB of 12.5 GHz ranging from 5.5 GHz to 18 GHz at a total thickness of 4.5 mm. The microwave attenuation mechanisms were studied by dielectric loss, magnetic loss and impedance matching. The multi-scale development of MXene-based magnetic composites makes them possible to applied to broadband microwave absorption.