Synthetic strategy of biomimetic sea urchin-like Co-NC@PANI modified MXene-based magnetic aerogels with enhanced electromagnetic wave absorption properties

The rational and effective combination of multicomponent materials and ingenious microstructure design for efficient electromagnetic wave (EMW) absorption are still challenging. In this paper, MXene was used as the aerogel matrix, modified with sea urchin-like magnetic Co/N-doped carbon@polyaniline (Co-NC@PANI), gelatin was introduced as the reinforcement phase of the aerogel backbone, and a microwave absorber with high efficiency and excellent performance was successfully prepared. The sea urchin-like Co-NC@PANI not only adjusted the impedance matching of the MXene but also introduced a magnetic loss mode into the composite. The multicomponent interfacial polarization, heterostructure, three-dimensional (3D) lightweight porous structure, and electromagnetic synergy strategy enabled the MXene-based aerogel modified by Co-NC@PANI (MCoP) to exhibit surprising EMW absorption properties. The maximum reflection loss (RL_max) of the aerogel composite reached -62.4 dB, and the effective absorption bandwidth (EAB) reached 6.56 GHz when the loading was only 12%. In addition, through electromagnetic simulation experiments, the change in the electromagnetic field before and after EMW passed through the materials and the distribution of the volume loss density of EMW by the coaxial ring were observed. The coordinated electromagnetic balance strategy in the 3D network provides inspiration for the construction of materials and expands the research direction of lightweight and outstanding microwave absorbers.