Lotus Leaf-Derived Gradient Hierarchical Porous C/MoS2 Morphology Genetic Composites with Wideband and Tunable Electromagnetic Absorption Performance

Abstract

Inspired by the nature, lotus leaf-derived gradient hierarchical porous C/MoS2 morphology genetic composites (GHPCM) were successfully fabricated through an in situ strategy. The biological microstructure of lotus leaf was well preserved after treatment. Different pores with gradient pore sizes ranging from 300 to 5 μm were hierarchically distributed in the composites. In addition, the surface states of lotus leaf resulted in the Janus-like morphologies of MoS2. The GHPCM exhibit excellent electromagnetic wave absorption performance, with the minimum reflection loss of − 50.1 dB at a thickness of 2.4 mm and the maximum effective bandwidth of 6.0 GHz at a thickness of 2.2 mm. The outstanding performance could be attributed to the synergy of conductive loss, polarization loss, and impedance matching. In particularly, we provided a brand-new dielectric sum-quotient model to analyze the electromagnetic performance of the non-magnetic material system. It suggests that the specific sum and quotient of permittivity are the key to keep reflection loss below − 10 dB within a certain frequency range. Furthermore, based on the concept of material genetic engineering, the dielectric constant could be taken into account to seek for suitable materials with designable electromagnetic absorption performance.

Flexible and Waterproof 2D/1D/0D Construction of MXene-Based Nanocomposites for Electromagnetic Wave Absorption, EMI Shielding, and Photothermal Conversion

“…When matching thickness (t m ) and matching frequency (f m ) satisfied this model, the reflected electromagnetic wave at the absorber-air interface was canceled out via destructive interference, thereby achieving the attenuation of the electromagnetic wave energy, which was due to the 180° phase difference between the incident and reflected electromagnetic wave in the absorbent [72][73][74]. Apparently, the Ti 3 C 2 T x /CNTs/Co nanocomposite conformed to this model, as shown in Fig.…”

Construction of 1D Heterostructure NiCo@C/ZnO Nanorod with Enhanced Microwave Absorption

“…7 b-c that the sample has multiple fluctuations at high-frequency bands, which implies that there is a significant polarization loss during the attenuation of the incident EMW, which could be due to the interfacial polarization caused by charge accumulation on heterogeneous junction surfaces and the dipole polarization occurring on defects or functional groups of materials. Both polarizations increase the dielectric loss capacity of the absorber [ 57 , 58 ]. The curves of μ ′ and μ ″ versus frequency of all samples (Fig.…”

Lightweight, Fire‐Retardant, and Anti‐Compressed Honeycombed‐Like Carbon Aerogels for Thermal Management and High‐Efficiency Electromagnetic Absorbing Properties

“…The attenuation constants (α) are estimated to evaluate the EM wave attenuation ability of CG and Co@C/CGs. [ 63 ] α values of the Co@C/CG‐800 and Co@C/CG‐900 are higher than those of CG, Co@C/CG‐600 and Co@C/CG‐700 (Figure S19, Supporting Information). Hence, the Co@C/CG‐800 and Co@C/CG‐900 also have better attenuation ability towards EM wave.…”