Tailoring Built‐In Electric Field in a Self‐Assembled Zeolitic Imidazolate Framework/MXene Nanocomposites for Microwave Absorption

Abstract

The use of heterointerface engineering, which can play a pivotal role in producing advanced microwave‐absorbing materials, to prepare a zeolitic imidazolate framework (ZIF)–MXene nanocomposite is reported herein. The ZIF–MXene composites can be prepared by electrostatic self‐assembly of negatively charged titanium carbide MXene flakes and positively charged Co‐containing ZIF nanomaterials. This approach effectively creates abundant Mott–Schottky heterointerfaces exhibiting a robust built‐in electric field (BIEF) effect, as evidenced by experimental and theoretical analyses, leading to a notable attenuation of electromagnetic energy. Systematic manipulation of the BIEF‐exhibiting heterointerface, achieved through topological modulation of the ZIF, proficiently alters charge separation, facilitates electron migration, and ultimately enhances polarization relaxation loss, resulting in exceptional electromagnetic wave absorption performance (reflection loss RLmin = −47.35 dB and effective absorption bandwidth fE = 6.32 GHz). The present study demonstrates an innovative model system for elucidating the interfacial polarization mechanisms and pioneers a novel approach to developing functional materials with electromagnetic characteristics through spatial charge engineering.This article is protected by copyright. All rights reserved

Constructing Built-In Electric Fields with Semiconductor Junctions and Schottky Junctions Based on Mo–MXene/Mo–Metal Sulfides for Electromagnetic Response

“…From Figs. 4 e and S25, it can be found that Mo–MXene/Mo–Sn sulfides exhibit excellent polarization loss [ 58 , 59 ]. Moreover, the presence of MoS 2 can provide additional conduction loss for the Mo–MXene/Mo–Sn sulfide heterostructures and enhance the attenuation ability [ 60 , 61 ].…”

“…When semiconductor junctions and Mott–Schottky junctions are built in Mo–MXene, MoS 2 , and Sn 2 S 3 , the electron density of the total density of orbital states (TDOS) of Mo–MXene/Mo–Sn sulfides changes (Fig. S45) [ 59 ]. This indicates that the construction of BIEF helps to modulate the electron migration ability of Mo–MXene/Mo–Sn sulfides.…”

“…7 h), which enhances interfacial polarization. The BIEF constructed in the Mo–MXene/Mo–metal sulfide heterostructure exhibits changes in energy band structure, which enhances the oscillatory polarization relaxation of space charges in an alternating electric field environment [ 59 ]. Specifically, the discrepancy in Fermi energy levels between the semiconductor MoS 2 and the semiconductor metal sulfides leads to the bending of semiconductor energy bands at the interface.…”

V-Based MXene/MAX Heterostructure Composites with Enhancing Dielectric Loss for Broadband Microwave Absorption

“…Furthermore, the larger the radius of the semicircle, the more pronounced the indication of polarization becomes. This could be attributed to the capacitance-like behavior exhibited by heterogeneous interfaces when subjected to electromagnetic waves, leading to charge redistribution at said interface. − Notably, the straight line at the end of the Cole–Cole curve progressively became longer with an increase in the MXene content. This implied that the conduction loss of the materials enhanced, which was attributed to the presence of heterogeneous interfaces, modified the rate or the mode of electron transfer, thus modulating the conduction loss.…”

Ultralight Hierarchical Fe3O4/MoS2/rGO/Ti3C2Tx MXene Composite Aerogels for High-Efficiency Electromagnetic Wave Absorption

“…This contributes to the optimization of the impedance-matching characteristics of the composite aerogel. To elucidate the magnetic storage and dissipation capabilities of composite aerogels, we further analyzed their complex permeability ( μ′ and μ″ ). , Figure S8a,b shows that the μ′ and μ″ values of Fe 3 O 4 /MoS 2 composite range from 0.95 to 1.05 and from 0 to 0.05, respectively, and fluctuate to varying degrees across the tested frequency range, implying a strong responsiveness to EM wave and notable magnetic storage/loss capacities. As illustrated in Figure d,e, the μ′ and μ″ values of GM and FMGM-1 are close to constants 1 and 0, respectively, indicating their weak magnetic nature, attributed to the low content of magnetic component.…”