Architecture-inspired N-doped carbon nanotube bridging well-arranged MXene nanosheets toward efficient electromagnetic wave absorption

Multilayered Ti3C2Tx MXene, due to its tunable dielectric constants and structural designability, has been identified as rising star for exploring high-efficiency electromagnetic wave absorbers. However, it is still a huge challenge to address insufficient external contact of multilayered MXene at lower filler loading. Herein, inspired by the layer-pillar-layer architecture, a controllable catalytic-assisted nitrogen-doped carbon nanotubes bridging strategy is rationally proposed on the interlaminations of multilayered MXene units (MXene/TiO2/NCNTs, denoted as MTNC) to enhance dielectric dissipation ability. Through chemical vapor deposition, the NCNTs bridges as pillars not only break the confinement effect of multilayered MXene architecture like the process of seed germination but also effectively optimize impedance matching and increase dielectric constants. Simultaneously, the unique NCNTs-encapsulated magnetic components successfully prevents the agglomerations of CoNi nanoparticles and local mismatching problems, which facilitates the construction of three-dimensional magnetic coupling network. Specifically, the N heteroatoms and formed TiO2 species induce dielectric polarization and corresponding relaxation processes. Driven by unique layer-pillar-layer architecture, optimized impedance matching, and synergistic dielectric-magnetic dissipation capabilities, the resultant absorber delivers outstanding reflection loss value of −55.8 dB and broad absorption bandwidth of 5.88 GHz. This work provides a novel structural design strategy and enlightenment for developing high-performance multilayered MXene-based absorbers.