Variety of ZIF-8/MXene-Based Lightweight Microwave-Absorbing Materials: Preparation and Performances of ZnO/MXene Nanocomposites

Abstract

Microwave-absorbing materials that are used for stealth weapons and equipment should have excellent characteristics of strong absorption, a wide absorption bandwidth, low thickness, and light weight. Ti 3 C 2 T x , as a twodimensional (2D) MXene material, shows great potential in the field of microwave absorption. However, MXene has problems of impedance mismatch, a narrow absorption bandwidth, and poor absorption performances. In this study, we designed a series of ZIF-8/MXene-based microwave-absorbing materials known as porous ZnO/MXene nanocomposites, which were synthesized by an in situ composite method before being annealed under vacuum. Then, the structure and performances of porous ZnO/MXene were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) and using a vector network analyzer (VNA). We investigated the influences of the mass ratio, microstructure, morphology, and microwave absorption performances of the samples on raw materials. As a result, ZnO/MXene nanocomposites with a mass ratio of Zn 2+ / MXene = 2:1 showed the optimum microwave absorption performance. The minimum reflection loss was −34.31 dB at 8.8 GHz (thickness 1.0 mm), and the effective absorption bandwidth was 3.47 GHz from 13.49 to 16.96 GHz.

Regulated electron migration in sandwich-like m-Ti3C2/Fe3O4 composites derived from electrostatic assembly boosted electromagnetic wave absorption

“…Such a phenomenon is common in MXenebased absorber design, especially when modifying materials with low-conductive llers. [66][67][68][69] Besides, Fe 3 O 4 exhibits a much larger area where the impedance matching value is far higher than 1 and accordingly shows a at 3D RL image, and the calculated matching thickness reaches an unacceptable value higher than 15 mm (Fig. S11 †).…”

Fabrication of the Fe-Doped Corona Schiff Base for Enhanced Microwave Absorption Performance

“…Dielectric polarization of six kinds of Schiff base materials is mainly caused by molecular polarization and molecular relaxation . Under the action of an alternating electromagnetic field, the molecular orientation rotation occurs, and polar molecules are disoriented by thermal motion, which forms a molecular relaxation process and results in energy loss in friction and collision. − From the electron micrograph of 6A, it can be seen that C3 mainly has a large number of spherical particles, which are more easily poled in an alternating electric field than the sheet Schiff base; therefore, C3 has a higher dielectric poling ability.…”

Snake Scale-Inspired Poly(vinylidene fluoride)/Ti3CNTx@Polypyrrole Coatings for Ultrawide-Bandwidth Microwave and Visible Light Absorption

“…Huang et al fabricated ZnO/MXene nanocomposites with heterogeneous nanostructures, which exhibited an EAB of 3.5 GHz and an RL min of −34.3 dB over Ku-band at a matching thickness of 1.0 mm. 24 Similarly, Wen et al employed a spheroidization strategy to assemble doubleshell MXene@Ni microspheres, achieving an RL min of −59.6 dB and an EAB of 4.4 GHz at a thickness of 1.5 mm. 25 However, the addition of metal or metal oxide results in high density and quality of the composite, which does not align with the ideal absorber goals.…”

“…To address this limitation, researchers have developed dielectric or magnetic/MXene-based composites to construct multiple heterogeneous interfaces and obtain EMA materials with good impedance matching and multiple loss mechanisms. Huang et al fabricated ZnO/MXene nanocomposites with heterogeneous nanostructures, which exhibited an EAB of 3.5 GHz and an RL min of −34.3 dB over Ku-band at a matching thickness of 1.0 mm . Similarly, Wen et al employed a spheroidization strategy to assemble double-shell MXene@Ni microspheres, achieving an RL min of −59.6 dB and an EAB of 4.4 GHz at a thickness of 1.5 mm .…”