Tunable Electromagnetic Wave Absorption of Supramolecular Isomer‐Derived Nanocomposites with Different Morphology

Abstract

Design and fabrication of highly efficient electromagnetic wave absorbing materials are yet challenging tasks, mainly caused by the lack of the in‐depth understanding of structure–property relationship. Herein, significant morphology effect on electromagnetic wave absorption is uncovered by pyrolyzing two isomeric metal–organic frameworks (MOFs: MIL‐101‐Fe and MIL‐88B‐Fe). The resultant pyrolyzed nanocomposites from these two MOFs with different topology under same pyrolysis condition have almost identical chemical composition (i.e., element type, element content, and valence state) and microstructure (i.e., particle size, pore size, and volume). As far as it is known, this work represents the first study on morphology control for superior electromagnetic wave absorption in carbon‐included composite system. Notably, an excellent performance of minimum reflection loss of −59.2 dB with a thickness of 4.32 mm and effective absorption bandwidth of 6.5 GHz with a thickness of 2 mm are achieved by Fe/C‐700@101 (700 represent the pyrolysis temperature; 101 stands for MIL‐101 precursor) and Fe/Fe3C/C‐800@101, respectively. This contribution will shed the light on design of advanced electromagnetic wave absorbers in future, especially from the perspective of fine morphology control.

Carbon-Based MOF Derivatives: Emerging Efficient Electromagnetic Wave Absorption Agents

“…The RL value reached − 52.9 dB at 3.07 mm, corresponding to an EAB of 4.64 GHz. Miao et al reported two isomeric MOFs (MIL-101-Fe with octahedral shape and MIL-88B-Fe with rod shape) derived Fe/C by pyrolysis at Ar atmosphere and studied the effect of morphology on EMW absorption [ 127 ]. Attributed to more abundant graphite flakes in MIL-101-Fe-derived Fe/C, the minimum RL value could reach − 59.2 dB with a thickness of 4.32 mm, and the EAB could achieve 5 GHz with a thickness of 1.8 mm.…”

A Review on Metal–Organic Framework-Derived Porous Carbon-Based Novel Microwave Absorption Materials

“…The morphology usually had significant effect on the MA performance. Kong pyrolyzed two MOFs with different topologies (MOFs: MIL-101-Fe and MIL-88B-Fe) under same pyrolysis condition, identical chemical composition and microstructure [ 155 ]. The RL max is − 59.2 dB with a thickness of 4.32 mm, and the EAB is 6.5 GHz with a thickness of 2 mm which are achieved by Fe/C-700@101 (700: pyrolysis temperature; 101: MIL-101 precursor) and Fe/Fe 3 C/C-800@101, respectively.…”

The development of a magnetic iron/nitrogen-doped graphitized carbon composite with boosted microwave attenuation ability as the wideband microwave absorber

“…[7][8][9][10] To be a high performing EM absorbing material, the absorption intensity, termed as reection loss value (RL), needs to be as low as possible. 11,12 In general, an RL value of À10 dB has been the qualied value, corresponding to 90% of the absorption coefficient. [13][14][15] The frequency band with RL < À10 dB is a crucial factor to estimate the EM absorption performance.…”