In situ modification of MXene nanosheets with polyaniline nanorods for lightweight and broadband electromagnetic wave absorption

MXene exhibits excellent electromagnetic (EM) wave attenuation ability, but its high dielectric constant is prone to impedance mismatch. Usually, the introduction of other components can adjust EM parameters and improve the impedance matching of MXene. In this paper, MXene/polyaniline (PANI) composites with lots of heterogeneous interfaces were designed and prepared by electrostatic self-assembly process, and PANI was used as impedance matching modifier of MXene to adjust the impedance matching of the composites and achieve greater reflection loss. The effect of the content of PANI nanorods loaded on MXene nanosheets on the EM properties of the material was discussed in this work. The maximum reflection loss (RL_max) of −60.6 dB corresponds to an effective absorption bandwidth (EAB) of 6.0 GHz for the composite with only 10% PANI loading, while the EAB reaches 8.64 GHz when the sample thickness is 2.3 mm. Moreover, the introduction of PANI balances the impedance matching of MXene while bridging individual MXene nanosheets to form a three-dimensional structure that increases the EM wave propagation path. The rich loss mechanisms such as interfacial polarization and dipole polarization provide effective attenuation of EM waves. This work provides a simple way to develop lightweight and broadband EM wave absorption materials.