Integrating Multi‐Heterointerfaces in a 1D@2D@1D Hierarchical Structure via Autocatalytic Pyrolysis for Ultra‐Efficient Microwave Absorption Performance

Abstract

Developing microwave absorption (MA) materials with ultrahigh efficiency and facile preparation method remains a challenge. Herein, a superior 1D@2D@1D hierarchical structure integrated with multi‐heterointerfaces via self‐assembly and an autocatalytic pyrolysis is designed to fully unlock the microwave attenuation potential of materials, realizing ultra‐efficient MA performance. By precisely regulating the morphology of the metal organic framework precursor toward improved impedance matching and intelligently integrating multi‐heterointerfaces to boosted dielectric polarization, the specific return loss value of composites can be effectively tuned and optimized to −1002 dB at a very thin thickness of 1.8 mm. These encouraging achievements shed fresh insights into the precise design of ultra‐efficient MA materials.

Metal/N-Doped Carbon Nanoparticles Derived from Metal–Organic Frameworks for Electromagnetic Wave Absorption

“…Therefore, an impedance matching ( Z = | Z in / Z 0 |) close to 1 indicates that most of the EMW enters the absorber and is attenuated. ,, The Z value of Co-NC is closest to 1 compared to all other samples, further confirming their strongest EMW absorption performance (Figure b). The abundant void space, the presence of doped heteroatoms, and the formation of metallic Co particles in Co-NC NPs contribute their good impedance matching. − Due to these features above, Co-NC exhibits robust EMW absorption performance, as demonstrated in Figure d and Table S1.…”

A Lightweight, Elastic, and Thermally Insulating Stealth Foam With High Infrared‐Radar Compatibility

“…Compared with PPM80/paraffin, the higher conductivity of PPM100/paraffin is not in favor of the impedance matching and results in more reflection at the surface of the absorber. [ 55 ] Due to the role of electrical conductivity in regulating impedance matching (too high or too low are not conducive to impedance matching), it becomes clear that the calculated Δ values are consistent with this property, showing an optimal point for PPM80/paraffin at an average Δ value of 0.53. Besides that, the engineered interfaces between PEDOT:PSS, 3D porous melamine foam and paraffin may provide long electromagnetic wave transmission paths and sufficient internal reflection space, which facilitates good input impedance.…”

Architecture inspired structure engineering toward carbon nanotube hybrid for microwave absorption promotion

“…The booming wireless communication technology, represented by the fifth generation (5G), as well as the proliferation of electronic devices brings society with great convenience in multiple fields; unfortunately, the consequent artificial electromagnetic (EM) pollution poses an increasing threat to both the physical health and living environment of human being ( Iqbal et al., 2020 ; Wu et al., 2019 , 2022 ; Wang et al., 2020a , 2020b ). To address these issues, carbon nanotubes (CNTs) known by their remarkable electrical conduction ability have been extensively employed to develop state-of-the-art microwave absorbing (MA) materials ( Huan et al., 2022 ; Xu et al., 2019 ; Wen et al., 2011 ; Che et al., 2006 ), by which a high conversion efficiency of transforming EM energy into Joule heat is expected. However, this peculiarity of CNTs also invites huge challenges in upgrading their MA performance toward a promising practical application owing to the intense skin effect and the ensuing easily evoked impedance mismatch.…”