Construction of 0D/1D/2D MXene nanoribbons-NiCo@NC hierarchical network and their coupling effect on electromagnetic wave absorption

The construction of MXene-based composites with rational hierarchical structures and networks has emerged as a promising candidate for high-performance electromagnetic wave (EMW) absorption, stemming from the unpredictable formation of multiple components and multiple interfaces. Herein, a stable and porous 0D/1D/2D MXene nanoribbons (NRs)-NiCo@NC hierarchical network consisting of 0D NiCo alloy embedded in nitrogen (N)-doped carbon (NiCo@NC), 1D Ti3C2Tx MXene nanoribbons, and 2D N-doped carbon nanosheets is rationally constructed for EMW absorption. The shearing effect of alkaline KOH can induce the formation of 1D MXene nanoribbons with staggered-connected nanoribbon network and macroporosity, which greatly increases the attenuation of multiple reflections of EMW. Meanwhile, MXene nanoribbons can serve as a structural network for the subsequent growth of 2D NiCo layered double hydroxide (LDH) ultrathin nanosheets as well as a conductive network for conduction loss. The 0D NiCo@NC derived from NiCo LDH nanosheets inherit excellent eddy current losses that contribute to magnetic loss and abundant N heteroatoms that contribute to dipole polarization. Furthermore, thanks to the coupling effect, 0D/1D/2D hierarchical network provides numerous interfaces that contribute to interfacial polarization and considerable exchange resonances that contribute to magnetic loss. As a result, 0D/1D/2D MXene nanoribbons-NiCo@NC hierarchical network exhibits robust EMW absorption performance with a reflection loss (R-L) value of -57.1 dB at a thickness of 4.82 mm and a R-L value of -33.19 dB at a thickness of only 1.4 mm. This study provides new inspiration for the future construction of EMW absorbers with hierarchical networks.