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    碳化温度对Mo2C/C纳米复合材料电磁波吸收性能的影响

    Effect of Carbonization Temperature on Electromagnetic Wave Absorption Properties of Mo2C/C Nanocomposites

    • 摘要: 采用室温搅拌法制备CuMo-金属有机骨架(MOFs)前驱体,经过不同温度(900,1 000,1 100 ℃)碳化处理,得到Mo2C/C复合材料,通过分析微观形貌、物相组成和电磁参数,研究了碳化温度对复合材料电磁波吸收性能的影响。结果表明:不同碳化温度下均制备得到了片状结构Mo2C/C复合材料,纳米级Mo2C颗粒镶嵌在碳骨架中;900℃碳化温度下复合材料中存在MoP杂质相,温度升至1 000℃时MoP相消失,复合材料发生进一步黏连形成多面体片层结构,当碳化温度升至1 100℃时,片层结构表面析出Mo2C纳米颗粒。随着碳化温度升高,复合材料的电磁波吸收和损耗能力先增强后减弱。当碳化温度为1 000 ℃时,复合材料在2.5 mm厚度下的有效吸收带宽达3.1 GHz,最小反射损耗为−20.8 dB,电磁波吸收性能最佳。

       

      Abstract: The CuMo-metal-organic frameworks (MOFs) precursor was prepared by room-temperature stirring method, and then was subjected to carbonization at different temperatures (900, 1 000, and 1 100 ℃) to prepare Mo2C/C composites. The effects of carbonization temperature on the electromagnetic wave absorption properties of the composites were studied by analyzing the microstructure, phase composition, and electromagnetic parameters. The results show that the flake-structured Mo2C/C composites were successfully synthesized at different carbonization temperatures, and nano-sized Mo2C particles embedded within the carbon skeleton. At the carbonization temperature of 900 ℃, an impurity phase of MoP appeared in the composites. When the temperature increased to 1 000 ℃, the MoP phase disappeared, the composites were further coalesced into a polyhedral lammellar structure. When the carbonization temperature increased to 1 100 ℃, Mo2C nanoparticles were precipitated on the surface of the lammellar structure. With the increase of carbonization temperature, the electromagnetic wave absorption and loss properties were first enhanced and then weakened. When the carbonization temperature was 1 000 ℃, the composite exhibited an effective absorption bandwidth of 3.1 GHz at a thickness of 2.5 mm and a minimum reflection loss of −20.8 dB, demonstrating a optimal electromagnetic wave absorption performance.

       

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