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Large Microsphere Structure of a Co/C Composite Derived from Co-MOF with Excellent Wideband Electromagnetic Microwave Absorption Performance
journal contributionposted on 2023-12-13, 03:43 authored by Mengyi Zhang, Xiaohui Sun, Xudong Cai, Xiaolu Zhan, Yufei Wu, Xuyang Zhang, Guohua Wu, Xiangwei Wang
In the field of electromagnetic wave (EMW) absorption, carbon matrix materials based on metal–organic frameworks (MOFs) have drawn more interest as a result of their outstanding advantages, such as porous structure, lightweight, controlled morphology, etc. However, how to broaden the effective absorption bandwidth [EAB; reflection loss (RL) ≤ −10 dB] is still a challenge. In this paper, large microsphere structures of a Co/C composite composed of small particle clusters were successfully prepared by the solvothermal method and annealing treatment. At a filling ratio of 40 wt %, the Co/C composite shows attractive microwave absorption (MA) performance after being annealed at 600 °C in an atmosphere of argon. With an EAB of 6.32 GHz (9.92–16.24 GHz) and a thickness of just 2.57 mm, the minimum RL can be attained at −54.55 dB. Most importantly, the EAB can attain 7.12 GHz (10.88–18.0 GHz) when the thickness is 2.38 mm, which is larger than that of the majority of MOF-derived composites. The superior MA performance is strongly related to excellent impedance matching and a higher attenuation constant. This study provides a simple strategy for synthesizing a MOF-derived Co/C composite with a wide EAB.
small particle clusterslarge microsphere structureshigher attenuation constantexcellent impedance matching92 – 1688 – 1840 wt %,600 ° clarge microsphere structurec composite composedeffective absorption bandwidthc composite derivedc compositeporous structurederived composites− 54successfully preparedstudy providesstrongly relatedsolvothermal methodsimple strategyreflection lossoutstanding advantagesfilling ratioelectromagnetic wavecontrolled morphologyattain 7annealing treatment57 mm55 db38 mm32 ghz24 ghz12 ghz0 ghz