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

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.