The positively charged MoO3/PDA microspheres are obtained by stacking and assembly of the sheet structure, and the negatively charged MXene nanosheets are wrapped on the surface through the principle of electrostatic self-assembly. After annealing, a nitrogen-doped carbon composite and a MXene-coated Mo2C wave absorber are obtained. The formation of the wrinkled surface provides a complex pore structure, and the multiple interface reflections between the nanosheets enhance the absorption performance. The existence of heterogeneous interfaces and the uneven distribution of space charges accumulated between the interfaces effectively reduce the minimum reflection loss (RLmin). This work explores the effects of the ratio between MoO3/PDA and MXene nanosheets and loading amount on the microwave absorption properties. Mo2C/NC@MXene-2 obtained when the ratio of the two is 3:1 has the best absorption performance under 25% loading. The RLmin is -59.36 dB, and the corresponding effective absorption bandwidth (EAB) is 4.6 GHz at 2.5 mm. This work expands the new applications of MXene-based and Mo2C-based materials and has a guiding significance for the design of electrostatic self-assembly materials.
Keywords: MXene nanosheets; Mo2C; electrostatic self-assembly; microwave absorber.