Abstract In this work, graphite nanosheets (GNs)/Co composites with excellent electromagnetic (EM) absorption performance was designed by a one-step hydrothermal method, and the surface of Co particles were coated with Co3O4 shell layer by a second hydrothermal method to obtain the expected core-shell GNs/Co@Co3O4 structure, and the microtopography, structure and magnetic properties of core-shell GNs/Co@Co3O4 structure were characterized in detail. EM analysis revealed that core-shell GNs/Co@Co3O4 structure has an excellent EM wave absorption performance. For GNs/Co@Co3O4, the excellent reflection loss (RL) is −55.16 dB with an ultra-thin matching thickness of 1.6 mm, and the effective absorption bandwidth (EAB) is 3.84 GHz (from 14.16 GHz to 18.00 GHz) with the ultra-thin matching thickness of only 1.2 mm. In this work, the two hydrothermal methods replaced the conventional core-shell structure method and obtained EM wave absorption core-shell Co@Co3O4/GNs with ultra-thin thickness, strong EM wave absorption capability, and broad absorption bandwidth.

中文翻译：

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在石墨纳米片表面生长的球形Co@Co3O4核壳复合材料具有超薄和优异的电磁吸收性能

摘要 本工作通过一步水热法设计了具有优异电磁（EM）吸收性能的石墨纳米片（GNs）/Co复合材料，并通过二次水热法在Co颗粒表面包覆了Co3O4壳层，获得了具有优异电磁（EM）吸收性能的石墨纳米片（GNs）/Co复合材料。对预期的核壳 GNs/Co@Co3O4 结构以及核壳 GNs/Co@Co3O4 结构的微观形貌、结构和磁性能进行了详细表征。EM分析表明核壳GNs/Co@Co3O4结构具有优异的EM波吸收性能。对于 GNs/Co@Co3O4，优异的反射损耗 (RL) 为 -55.16 dB，超薄匹配厚度为 1.6 mm，有效吸收带宽 (EAB) 为 3.84 GHz（从 14.16 GHz 到 18.00 GHz），具有超薄匹配厚度仅为1.2毫米。在这项工作中，