Multifunctional MXene/C Aerogels for Enhanced Microwave Absorption and Thermal Insulation

Nano-Micro Letters, Год журнала: 2023, Номер 15(1)

Опубликована: Авг. 9, 2023

Two-dimensional transition metal carbides and nitrides (MXene) have emerged as promising candidates for microwave absorption (MA) materials. However, they also some drawbacks, such poor impedance matching, high self-stacking tendency, density. To tackle these challenges, MXene nanosheets were incorporated into polyacrylonitrile (PAN) nanofibers subsequently assembled a three-dimensional (3D) network structure through PAN carbonization, yielding MXene/C aerogels. The 3D effectively extends the path of microcurrent transmission, leading to enhanced conductive loss electromagnetic (EM) waves. Moreover, aerogel's rich pore significantly improves matching while reducing density MXene-based absorbers. EM parameter analysis shows that aerogels exhibit minimum reflection (RLmin) value - 53.02 dB (f = 4.44 GHz, t 3.8 mm), an effective bandwidth (EAB) 5.3 GHz (t 2.4 mm, 7.44-12.72 GHz). Radar cross-sectional (RCS) simulations employed assess radar stealth effect aerogels, revealing maximum RCS reduction perfect electric conductor covered by aerogel reaches 12.02 m2. In addition MA performance, demonstrates good thermal insulation 5-mm-thick can generate temperature gradient over 30 °C at 82 °C. This study provides feasible design approach creating lightweight, efficient, multifunctional

Язык: Английский

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Excellent microwave absorption performance of LaFeO3/Fe3O4/C perovskite composites with optimized structure and impedance matching

Carbon, Год журнала: 2023, Номер 213, С. 118200 - 118200

Опубликована: Июнь 7, 2023

Язык: Английский

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Advancements in Microwave Absorption Motivated by Interdisciplinary Research

Advanced Materials, Год журнала: 2023, Номер 36(4)

Опубликована: Окт. 23, 2023

Abstract Microwave absorption materials (MAMs) are originally developed for military purposes, but have since evolved into versatile with promising applications in modern technologies, including household use. Despite significant progress bench‐side research over the past decade, MAMs remain limited their scope and yet to be widely adopted. This review explores history of from first‐generation coatings second‐generation functional absorbers, identifies bottlenecks hindering maturation. It also presents potential solutions such as exploring broader spatial scales, advanced characterization, introducing liquid media, utilizing novel toolbox (machine learning, ML), proximity lab end‐user. Additionally, it meticulously compelling medicine, mechanics, energy, optics, sensing, which go beyond efficiency, along current development status prospects. interdisciplinary direction differs previous primarily focused on meeting traditional requirements (i.e., thin, lightweight, wide, strong), can defined next generation smart absorbers. Ultimately, effective utilization ubiquitous electromagnetic (EM) waves, aided by third‐generation MAMs, should better aligned future expectations.

Язык: Английский

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"Three-in-One" Multi-Scale Structural Design of Carbon Fiber-Based Composites for Personal Electromagnetic Protection and Thermal Management

Nano-Micro Letters, Год журнала: 2023, Номер 15(1)

Опубликована: Июль 10, 2023

Wearable devices with efficient thermal management and electromagnetic interference (EMI) shielding are highly desirable for improving human comfort safety. Herein, a multifunctional wearable carbon fibers (CF) @ polyaniline (PANI) / silver nanowires (Ag NWs) composites "branch-trunk" interlocked micro/nanostructure were achieved through "three-in-one" multi-scale design. The reasonable assembly of the three kinds one-dimensional (1D) materials can fully exert their excellent properties i.e., superior flexibility CF, robustness PANI, splendid conductivity AgNWs. Consequently, constructed flexible composite demonstrates enhanced mechanical tensile stress 1.2 MPa, which was almost 6 times that original material. This is mainly attributed to fact PNAI (branch) firmly attached CF (trunk) polydopamine (PDA), forming robust structure. Meanwhile, possesses insulation heat preservation capacity owing synergistically low emissivity. More importantly, conductive path established by 1D greatly improved its EMI property Joule heating performance at applied voltage. work paves way rational utilization intrinsic materials, as well provides promising strategy designing protection energy devices.

Язык: Английский

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The Elaborate Design of Multi‐Polarization Effect by Non‐Edge Defect Strategy for Ultra‐Broad Microwave Absorption

Advanced Functional Materials, Год журнала: 2024, Номер 34(44)

Опубликована: Май 21, 2024

Abstract Anion defect engineering is proven to be an efficient approach reconstruct the electronic configuration of carbon‐based magnetoelectric materials for targeted modulation electromagnetic (EM) performance. However, traditional mono‐anionic doping suffers from low concentration and lacks diverse polarization mechanisms. In this work, multi‐anions (N/S/F) stepwise‐doped carbon/Fe 3 C composites are elaborately constructed, wherein predesigned N defects serve as activated sites anomalously adopting S anions (Step I) subsequent F II) in non‐marginal areas carbon layer. It found that prefers replace pyrrolic while tends form dangling bonds with site adjacent pyridinic N. Intriguingly, besides inherent polarized resonance at ≈15 GHz, customized induce new resonances ≈10 GHz ≈15+ respectively. Under a typical multi‐polarization effect synergetic magnetic response, N/S/F harvest broadest bandwidth 8.28 (9.72–18 GHz) 2.55 mm, covering wide frequency range almost X Ku bands. This work demonstrates positive impact localized multi‐defects customization on expanding microwave absorption bandwidth, providing valuable insights advanced design ultra‐broadband absorbers.

Язык: Английский

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Interface-induced dual-pinning mechanism enhances low-frequency electromagnetic wave loss

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Апрель 17, 2024

Abstract Improving the absorption of electromagnetic waves at low-frequency bands (2-8 GHz) is crucial for increasing (EM) pollution brought about by innovation fifth generation (5G) communication technology. However, poor impedance matching and intrinsic attenuation material in hinders development wave absorbing (EMWA) materials. Here we propose an interface-induced dual-pinning mechanism establish a magnetoelectric bias interface constructing bilayer core-shell structures NiFe 2 O 4 (NFO)@BiFeO 3 (BFO)@polypyrrole (PPy). Such heterogeneous could induce distinct magnetic pinning moment ferromagnetic NFO dielectric dipole rotation PPy. The establishment effect resulted optimized enhanced bands, leading to better EMWA performance. minimum reflection loss (RL min ) thickness 4.43 mm reaches -65.30 dB (the optimal efficiency 99.99997%), effective bandwidth (EAB) can almost cover C-band (4.72 ~ 7.04 with low filling 15.0 wt.%. This work proposes optimize (EMW) pave avenue research high-performance absorbers.

Язык: Английский

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Interface Engineering of Heterogeneous NiSe₂‐CoSe₂@C@MoSe₂ for High‐Efficient Electromagnetic Wave Absorption

Advanced Functional Materials, Год журнала: 2023, Номер 34(9)

Опубликована: Ноя. 14, 2023

Abstract Optimization of components and micromorphology regulation are shown to be effective in boosting electromagnetic wave absorption (EMWA). One approach achieve this enhancement is by utilizing the polarization effects heterogeneous interfaces. Herein, NiSe 2 ‐CoSe @C@MoSe composites derived from NiCo‐MOF‐74 fabricated via a facile selenization reaction subsequent hydrothermal method. By varying mass ratios @C MoSe , series with hierarchical flower‐like core–shell structures obtained. The EMWA properties display trend initially increasing then decreasing content . Interestingly, when ratio 3:2, minimum reflection loss (RL) value −50.10 dB an bandwidth (RL< −10 dB) can reach 4.80 GHz (13.20–18.00 GHz). remarkable capability ascribed synergy conductive loss, suitable impedance matching. This work establishes new pathway for synthesis transition metal dichalcogenides‐based composites, which hold great promise as high‐performance materials applications.

Язык: Английский

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Ultrasonic Field Induces Better Crystallinity and Abundant Defects at Grain Boundaries to Develop CuS Electromagnetic Wave Absorber

Advanced Materials, Год журнала: 2023, Номер 35(49)

Опубликована: Авг. 11, 2023

Ultrasonic field (USF) is widely used to regulate the intrinsic properties of materials that are not applied in electromagnetic wave (EMW) absorption. One reason lack a response mechanism for USF hinders expansion their EMW absorption performance. Therefore, address this issue, series CuS nanoparticles with diverse anions constructed presence or absence USF. The ultrasonic-induced cavitation effect can significantly promote crystallization and lead accumulation S defects at grain boundaries (GBs). Furthermore, GBs easily oriented arranged, allowing polarization relaxation retention be maintained 10 wt%. Consequently, nitrate precursor under shows an optimum effective bandwidth (EAB) 10.24 GHz thickness 3.5 mm, which 228.6% more than without chloride also achieves EAB 3.92 GHz, even considerably low filler ratio. Thus, study demonstrates first time provides novel technique optimize performance semiconductors.

Язык: Английский

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Hierarchical Fe-Co@TiO₂ with Incoherent Heterointerfaces and Gradient Magnetic Domains for Electromagnetic Wave Absorption

ACS Nano, Год журнала: 2023, Номер 18(1), С. 560 - 570

Опубликована: Дек. 18, 2023

Induced polarization response and integrated magnetic resonance show prosperous advantages in boosting electromagnetic wave absorption but still face huge challenges revealing the intrinsic mechanism. In this work, we propose a self-confined strategy to construct hierarchical Fe-Co@TiO2 microrods with numerous incoherent heterointerfaces gradient domains. The results demonstrate that use of polyvinylpyrrolidone (PVP) coating is crucial for subsequent deposition Co-zeolitic imidazolate frameworks (ZIF-67), distance ordered arranged metal ions manipulates size domains, pyrolysis PVP layers restricts eutectic process Fe-Co alloys some extent. As result, these introduced lattice defects, oxygen vacancies, inevitably generate strong response, regulated domains realize resonance, including macroscopic coupling, long-range diffraction, nanoscale bridge connection, both mechanisms dissipating energy are quantitatively clarified by Lorentz off-axis electron holography. Owing cooperative merits, absorbents exhibit enhanced intensity bandwidth. This study inspires us develop generalized manipulating theory provides versatile methodology clarifying loss

Язык: Английский

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Porous magnetic carbon spheres with adjustable magnetic-composition and synergistic effect for lightweight microwave absorption

Carbon, Год журнала: 2023, Номер 213, С. 118290 - 118290

Опубликована: Июль 11, 2023

Язык: Английский

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