A Facile Synthesis of NiFe-Layered Double Hydroxide and Mixed Metal Oxide with Excellent Microwave Absorption Properties

Abstract

Microwave-absorbing materials have attracted increased research interest in recent years because of their core roles in the fields of electromagnetic (EM) pollution precaution and information security. In this paper, microwave-absorbing material NiFe-layered double hydroxide (NiFe-LDH) was synthesized by a simple co-precipitation method and calcined for the fabrication of NiFe-mixed metal oxide (NiFe-MMO). The phase structure and micromorphology of the NiFe-LDH and NiFe-MMO were analyzed, and their microwave-absorbing properties were investigated with a vector network analyzer in 2–18 GHz. Both NiFe-LDH and NiFe-MMO possessed abundant interfaces and a low dielectric constant, which were beneficial to electromagnetic wave absorption, owing to the synergistic effect of multi-relaxation and impedance matching. The optimum reflection loss (RL) of NiFe-LDH and NiFe-MMO was −58.8 dB and −64.4 dB, respectively, with the thickness of 4.0 mm in the C band. This work demonstrates that LDH-based materials have a potential application in electromagnetic wave absorption.

Facile synthesis of a 2D multilayer core–shell MnO2@LDH@MMT composite with a nanoflower shape for electromagnetic wave absorption

“…42 Significant fluctuations can be seen at high frequencies (14–18 GHz) because the polarization is largely influenced by the frequency, and the electron exchange between Fe 3+ and Ni 2+ ions in MNFM and the special heterogeneous structure induced by the alternating electric field lead to a large amount of space and polarization charges, resulting in small fluctuations at high frequencies. 43 From Fig. 5(a and b), the permittivity of MNFM is higher than that of NFM, and the ε ′ value of MNFM is greater than that of NFM, which can be explained by the incorporation of MnO 2 , which gives MNFM a better impedance match and provides MNFM with a multilayer structure and nano-sheet layers that provide more incidence and storage channels for electromagnetic waves.…”

“…It was demonstrated that the domain wall resonance occurs within a very small band of frequencies, so the domain wall displacement loss is not considered. 43 Its eddy current loss is described as follows: C o = μ ′′( μ ′) −2 f −1 = 2π μ o d 2 δ . 45 Fig.…”

“…It was demonstrated that the domain wall resonance occurs within a very small band of frequencies, so the domain wall displacement loss is not considered. 43 Its eddy current loss is described as follows: 45 Fig. 7c shows that the C o values and μ″ remain in the same range, and at 9-18 GHz, the C o values of the composite remain essentially constant, with small fluctuations present, which are mainly caused by eddy current losses and exchange resonances (10)(11)(12)(13)(14)(15)(16)(17)(18).…”

Recent Progress in Iron-Based Microwave Absorbing Composites: A Review and Prospective

“…Resistive absorbing materials such as carbon materials have the advantages of high conductivity loss, low density and abundant dipoles, but they have poor impedance matching characteristics and high reflectivity; thus, it is difficult for electromagnetic waves to incident into the material, and a large number of electromagnetic waves are reflected into space, resulting in secondary pollution [9,10]. Magnetic metal wave-absorbing materials have excellent properties, such as high dielectric constant and permeability, high magnetic loss, high cut-off frequency, high saturation magnetization strength, and good temperature stability, which are a class of wave-absorbing materials with great development potential and application prospects [11][12][13]. Among them, Fe magnetic metal has the best performance, the most research, and the most extensive application.…”

FeNi LDH/Loofah Sponge-Derived Magnetic FeNi Alloy Nanosheet Array/Porous Carbon Hybrids with Efficient Electromagnetic Wave Absorption

“…7,8 Although singlecomponent EMW absorption materials with satisfactory EMW absorption performance to some degrees have been reported, their disadvantages such as large filler content, high density, and narrow effective absorption bandwidth extremely limit their practical applications. 8,9 Consequently, recent studies focused on the rational incorporation of the dielectric component and magnetic component with an ingenious structure to realize high-performance EMW absorption. 10 Many typical biomass-derived carbon-based porous materials, such as wheat straw, pomelo peel, and wood, have attracted tremendous attention to fabricate efficient EMW absorption materials with a low filler content, low density, and broad effective absorption bandwidth because they can provide abundant inherent microscale pores for scattering and multiple reflections of electromagnetic waves.…”