Conductive Metal–Organic Frameworks with Tunable Dielectric Properties for Boosting Electromagnetic Wave Absorption

ACS Nano, Journal Year: 2023, Volume and Issue: 17(13), P. 12510 - 12518

Published: June 23, 2023

Metal-organic frameworks (MOFs) manifest enormous potential in promoting electromagnetic wave (EMW) absorption thanks to the tailored components, topological structure, and high porosity. Herein, rodlike conductive MOFs (cMOFs) composed of adjustable metal ions Zn, Cu, Co, or Ni ligands hexahydroxytriphenylene (HHTP) are prepared attain tunable dielectric properties for a EMW absorption. Specifically, influences cMOFs' composition, charge transport characteristic, crystalline anisotropy microstructure on performance ascertained, advancing understanding attenuation mechanisms MOFs. The boosted polarization losses derived from conjugation effects terminal groups, as well shape anisotropy, lead prominent cMOFs. Cu-HHTP confers minimum reflection loss (RLmin) -63.55 dB at thickness 2.9 mm maximum effective bandwidth 5.2 GHz. Moreover, Zn-HHTP showcases superiority S-band (2-4 GHz) with an RLmin -62.8 1.9 mm. This work not only hoists mechanistic structure-function relationships cMOFs but also offers guidelines preparing functional MOF materials.

Language: Английский

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Multifunctional Organic–Inorganic Hybrid Perovskite Microcrystalline Engineering and Electromagnetic Response Switching Multi‐Band Devices

Advanced Materials, Journal Year: 2023, Volume and Issue: 35(25)

Published: March 19, 2023

High-efficiency electromagnetic (EM) functional materials are the core building block of high-performance EM absorbers and devices, they indispensable in various fields ranging from industrial manufacture to daily life, or even national defense security space exploration. Searching for high-efficiency realizing devices remain great challenges. Herein, a simple solution-process is developed rapidly grow gram-scale organic-inorganic (MAPbX3 , X = Cl, Br, I) perovskite microcrystals. They exhibit excellent response multi bands covering microwaves, visible light, X-rays. Among them, outstanding microwave absorption performance with multiple can be achieved, their intrinsic properties tuned by adjusting polar group. An ultra-wideband bandpass filter high suppression level -71.8 dB stopband GHz band, self-powered photodetectors tunable broadband narrowband photoresponse visible-light X-ray detector sensitivity 3560 µC Gyair-1 cm-2 band designed realized precisely regulating physical features designing novel planar device structure. These findings open door toward developing devices.

Language: Английский

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Liquid‐Metal‐Assisted Programmed Galvanic Engineering of Core–shell Nanohybrids for Microwave Absorption

Advanced Functional Materials, Journal Year: 2023, Volume and Issue: 33(34)

Published: May 17, 2023

Abstract Core–shell nanostructures have received widespread attention because of their potential usage in various technological and scientific fields. However, they still face significant challenges terms fabrication core–shell nanostructure libraries on a controlled, even programmed scale. This study proposes general approach to systematically fabricate nanohybrids using liquid‐metal Ga alloys as reconfigurable templates, the initiation local galvanic replacement reaction is demonstrated utilizing an ultrasonic system. Under agitation, hydrated gallium oxides generated liquid metal droplets, simultaneously delaminated themselves from interfaces. Subsequently, single‐metal or bimetallic components are deposited fresh smooth Ga‐based via reactions form unique metal/metal nanohybrids. Controlled quantitative regulation diversity non‐homogeneous nanoparticle shell layer composition achieved. The obtained used efficient microwave absorbers dissipate unwanted electromagnetic wave pollution. effective absorption bands (90% absorption) GaNi GaCoNi 3.92 3.8 GHz at thickness 1.4 mm, respectively. advanced strategy enables growth other sulfides by spontaneous interfacial redox for functional materials future.

Language: Английский

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Advancements in Microwave Absorption Motivated by Interdisciplinary Research

Advanced Materials, Journal Year: 2023, Volume and Issue: 36(4)

Published: Oct. 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.

Language: Английский

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Metal-organic frameworks with fine-tuned interlayer spacing for microwave absorption

Science Advances, Journal Year: 2024, Volume and Issue: 10(11)

Published: March 13, 2024

Designing a functional, conductive metal-organic framework (cMOF) is highly desired. Substantial efforts have been dedicated to increasing the intralayer conjugation of cMOFs, while less dedication has made tuning interlayer charge transport nanosheets for controllable dielectric property. Here, we construct series bimetallic organic frameworks (Zn x Cu 3-x ) (hexahydroxytriphenylene) 2 (ZnCu-HHTP) allow fine-tuned spacing two-dimensional frameworks, by adjusting ratios Zn and metal ions. This approach atomistic design allows finely control transport, band structure, properties cMOF. As result, Zn3Cu1-HHTP, with an optimal property, exhibits high-efficiency absorption in gigahertz microwave range, achieving ultra-strong reflection loss −81.62 decibels. study not only advances understanding microstructure-function relationships cMOFs but also offers generic nanotechnology–based MOFs targeted applications.

Language: Английский

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A perspective on impedance matching and resonance absorption mechanism for electromagnetic wave absorbing

Carbon, Journal Year: 2024, Volume and Issue: 222, P. 118935 - 118935

Published: Feb. 13, 2024

Language: Английский

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Recent progress in carbon-based materials and loss mechanisms for electromagnetic wave absorption

Carbon, Journal Year: 2024, Volume and Issue: 219, P. 118834 - 118834

Published: Jan. 18, 2024

Language: Английский

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Perspectives of nitrogen-doped carbons for electromagnetic wave absorption

Carbon, Journal Year: 2024, Volume and Issue: 221, P. 118925 - 118925

Published: Feb. 10, 2024

Language: Английский

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Regulation of Impedance Matching and Dielectric Loss Properties of N‐Doped Carbon Hollow Nanospheres Modified With Atomically Dispersed Cobalt Sites for Microwave Energy Attenuation

Small, Journal Year: 2023, Volume and Issue: 19(28)

Published: March 28, 2023

The rational design of lightweight, broad-band, and high-performance microwave absorbers is urgently required for addressing electromagnetic pollution issue. Metal single atoms (M-SAs) receive considerable interest in the field absorption due to unique electronic structures M-SAs. However, simultaneous engineering morphology structure M-SAs based remains challenging. Herein, a template-assisted method utilized fabricate isolated Co-SAs on N-doped hollow carbon spheres (NHCS@Co-SAs) absorption. combination atomically dispersed Co sites supports endows NHCS@Co-SAs with excellent properties. Typically, at an ultralow filler content 8 wt%, minimum reflection loss effective bandwidth are up -44.96 dB 5.25 GHz, respectively, while absorbing thickness only 2 mm. Theoretical calculations experimental results indicate that impedance matching characteristic dielectric NHCSs can be tuned via introduction M-SAs, which responsible properties NHCS@Co-SAs. This work provides atomic-level insight into relationship between states their developing advanced absorbers.

Language: Английский

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Self‐Assembled 3D N/P/S‐Tridoped Carbon Nanoflower with Highly Branched Carbon Nanotubes as Efficient Bifunctional Oxygen Electrocatalyst Toward High‐Performance Rechargeable Zn‐Air Batteries

Advanced Functional Materials, Journal Year: 2023, Volume and Issue: 34(16)

Published: Dec. 28, 2023

Abstract Heteroatom doping and 3D nanostructures with large specific surface area hierarchical porous structure can synergically improve oxygen reduction reaction (ORR) evolution (OER). In this study, the N/P/S‐tridoped nanoflower highly branched carbon nanotubes bifunctional catalyst (Co/SP‐NC) is prepared by a simple self‐assembly pyrolysis method. The powerful driving force of coordination interaction ammonium ion promote 2D ZnCo‐ZIF nanosheets into ZnCo/S‐ZIF nanoflowers at room temperature stirring. driven sodium hypophosphite to form during process. Moreover, Density functional theory (DFT) calculations also confirm that simultaneous introduction N/P/S redistribution electron density interface. proper P‐doping not only enhances electronic conductivity substrate, but facilitates charge transfer in OER/ORR Therefore, Co/SP‐NC cathode assembled zinc‐air batteries (ZABs) have higher power (187 mW cm −2 ), larger capacity (801 mAh g Zn −1 ) excellent cycle stability compared Pt/C‐RuO 2 ZABs. This work will pave way regulate components interactions designing structures.

Language: Английский

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