Hierarchically flower-like structure assembled with porous nanosheet-supported MXene for ultrathin electromagnetic wave absorption

[Display omitted] •Co/ZnO@CMWCNTs/Ti3C2Tx composite exhibited hierarchically porous flower-like assembled with MXene nanosheet were prepared.•The minimum reflection loss of the composite is up to −46 dB at 1.5 mm.•The modulation of electromagnetic parameters was achieved by controlling the load of MXene.•Excellent performance comes from the effect of dielectric loss and magnetic loss. The design of a hierarchical three-dimensional (3D) structure is beneficial to suppressing the accumulation of MXene flakes and obtaining satisfactory lightweight, efficient, and broadband-absorbing materials. Undoubtedly, the exploration of electromagnetic wave (EMW) absorbing materials with stronger absorption and thinner thickness of multi-component and multi-mechanism synergy is in great demand, but it is still a challenge. In this paper, we report for the first time a well-designed and optimized electrostatic self-assembly anchored Ti3C2Tx nanosheet to prepare porous flower-like Co/ZnO@CMWCNTs/Ti3C2Tx (CZCT) composites. The electromagnetic parameters and EMW absorption properties of carboxylated multi-walled carbon nanotubes (CMWCNTs) and Ti3C2Tx nanosheets can be controlled by adjusting the load of CMWCNTs and Ti3C2Tx nanosheets. Based on the multi-dimensional material collaboration and electromagnetic synergistic strategy, the flower-like CZCT composite achieves a significant minimum reflection loss (RLmin) of −46 dB at a thickness of 1.5 mm. The maximum effective absorption bandwidth (EABmax) of 4 GHz is 1.9 mm. This work provides a simple strategy for building MXene-based composites to achieve efficient EMW absorption materials with lightweight and adjustable EAB.