Coupling between the 2D Ligand and 2D Host and Their Assembled Hierarchical Heterostructures for Electromagnetic Wave Absorption

Constructing the strong interaction between the matrix and the active centers dominates the design of highperformance electromagnetic wave (EMW) absorption materials. However, the interaction-relevant absorption mechanism is still unclear, and the design of ultrahigh reflection loss (R-L < -80 dB) absorbers remains a great challenge. Herein, CoFe-based Prussian blue (PB) nanocubes are coprecipitated on the surface of ultrathin CoAl-LDH nanoplates with the assistance of unsaturated coordination sites. During the subsequent pyrolysis process, CoAl-LDH serves as a ligand providing a Co source and reacts with Fe or C in the CoFe-PB host to form stable CoFe alloys or CoCx species. As a result, strong reactions emerged between the CoAl-LDH matrix and the active CoFe-CoCx@NC centers. Based on the experimental results, the CoAl/CoFe-CoCx@NC hierarchical heterostructure delivers good dielectric losses (dipolar polarization, interface polarization, and conductive loss), magnetic losses (eddy current loss, natural resonance, and exchange resonance), and impedance matching, resulting in a remarkable EMW absorption performance with a reflection loss (R-L) value of -82.1 dB at a matching thickness of 3.8 mm. Theoretical results (commercial CST) identify that the strong interaction between the 2D CoAl-LDH ligand and 2D CoFe-CoCx host promotes a robust heterointerface among the nanoparticles, nanosheets, and nanoplates, which extremely contribute to the dielectric loss. Meanwhile, the coupling effect of nanosheets and nanoplates greatly contributes to the matching performance. This work provides an aggressive strategy for the effect of ligands and hosts on high-performance EMW absorption.

Automated summary

The strong interaction between the matrix and the active centers plays a crucial role in the design of high-performance electromagnetic wave absorption materials. This study successfully designed a material with excellent electromagnetic wave absorption performance by constructing a strong interaction between CoAl-LDH matrix and CoFe-CoCx@NC centers. The experimental and theoretical results demonstrate the importance of material combination and structure in achieving high reflection loss and good matching performance.