Kirkendall Effect‐Induced Ternary Heterointerfaces Engineering for High Polarization Loss MOF‐LDH‐MXene Absorbers

Abstract

Heterogeneous interfacial engineering has garnered widespread attention for optimizing polarization loss and enhancing the performance of electromagnetic wave absorption. A novel Kirkendall effect‐assisted electrostatic self‐assembly method is employed to construct a metal–organic framework (MOF, MIL‐88A) decorated with Ni‐Fe layered double hydroxide (LDH), forming a multilayer nano‐cage coated with Ti₃C₂T_x. By modulating the surface adsorption of Ti₃C₂T_x on LDH, the heterointerfaces in MOF‐LDH‐MXene ternary composites exhibit excellent interfacial polarization loss. Additionally, the Ni‐Fe LDH@Ti₃C₂T_x nano‐cage exhibits a large specific surface area, abundant defects, and a large number of heterojunction structures, resulting in excellent electromagnetic wave absorption performance. The MIL‐88A@Ni‐Fe LDH@Ti₃C₂T_x‐1.0 nano‐cage achieves a reflection loss value of −46.7 dB at a thickness of 1.4 mm and an effective absorption bandwidth of 5.12 GHz at a thickness of 1.8 mm. The heterojunction interface composed of Ni‐Fe LDH and Ti₃C₂T_x helps to enhance polarization loss. Additionally, Ti₃C₂T_x forms a conductive network on the surface, while the cavity between the MIL‐88A core and the Ni‐Fe LDH shell facilitates multiple attenuations by increasing the transmission path of internal incident waves. This work may reveal a new structural design of multi‐component composites by heterointerfaces engineering for electromagnetic wave absorption.