Self-assembly magnetized 3D hierarchical graphite carbon-based heterogeneous yolk–shell nanoboxes with enhanced microwave absorption

Abstract

Graphite carbon is transformed from thin layers into a 3D hierarchical structure via self-assembly during a specific hydrothermal process. Nano-scale magnetic coupling networks and various forms of losses play active roles in microwave absorption.

A water-induced self-assembly approach to 3D hierarchical magnetic MXene networks for enhanced microwave absorption

“…In general, the real part of complex permittivity (3 ′ ) and complex permeability (m ′ ) reects the ability of absorbers to store electromagnetic energy, while the imaginary part of complex permittivity (3 ′′ ) and complex permeability (m ′′ ) represents the loss capability of energy. 46 As shown in Fig. 5a and b, due to the introduction of MXene networks, both the 3 ′ and 3 ′′′ of ZFCM series are signicantly elevated.…”

“…5g and S19 †), which may arise from interfacial polarization and dipolar polarization. 23,46 The continuous interfaces between the three phases of MXene, carbon matrixes, and magnetic nanocrystals can signicantly trigger the interfacial polarization. 50 The residual end groups, the intrinsic defects, and the oxidation-generated defects of MXene as well as the defects in carbon matrixes can lead to the asymmetry of electron spatial distribution and the formation of dipole moment, resulting in dipolar polarization under microwave irradiation.…”

Morphology-Controlled Fabrication Strategy of Hollow Mesoporous Carbon Spheres@f-Fe2O3 for Microwave Absorption and Infrared Stealth

“…Furthermore, in the range of 1200–1800 cm –1 , HMCS and all HMCS@f-Fe 2 O 3 - x samples demonstrated two distinguishable peaks, that is, one broad peak centered at ∼1340 cm –1 (D-band) and the other relatively sharp peak at ∼1590 cm –1 (G-band) in Figure c. It has been well documented that the intensity ratio of D-band to G-band ( I D / I G ) is usually utilized to estimate the graphitization degree. , However, it could be found that all samples displayed similar I D / I G values, indicating that the carbon components in these composites have a similar graphitization degree. Moreover, TG curves were carried out to determine the weight fractions of f-Fe 2 O 3 in HMCS@f-Fe 2 O 3 - x composites (Figure d).…”

“…It has been well documented that the intensity ratio of D-band to G-band (I D /I G ) is usually utilized to estimate the graphitization degree. 26,27 However, it could be found that all samples displayed similar I D /I G values, indicating that the carbon components in these composites have a similar graphitization degree. Moreover, TG curves were carried out to determine the weight fractions of f-Fe 2 O 3 in HMCS@f-Fe 2 O 3 -x composites (Figure 3d).…”

Review and Perspective of Tailorable Metal‐Organic Framework for Enhancing Microwave Absorption

“…[ 200 ] The yolk‐shell structures could also be obtained through coating–coating‐carbonization‐etching process (Figure 15). [ 203 ] The content and concentration of the etching agent determine the size of the yolk core. It is worth noting that the synthesis strategy of CoSnO 3 ‐MOF precursor has been switched from hydrothermal to solvent‐free synthesis, and the obtained CoSn/NC composites maintained the morphologies of nanocubes, which display an RL min of –48.2 dB and an EAB value of 5.84 GHz at 2.2 mm.…”