Recently, Prussian blue analogs (PBAs) have attracted much attention due to their transformation into dielectric/magnetic coupled composites after pyrolysis at high temperatures and their ability to maintain their basic morphology. However, designing efficient microwave-absorbing materials using PBAs is still a challenge. In this work, Co–Fe PBA was prepared by wet chemical method and graphene aerogel-encapsulated double carbon-shell CoFe@C@C nanocubes (CFCCG) were prepared by stirred self-polymerization and hydrothermal method, and heat-treated at different temperatures to obtain composites consisting of core-shell-structured PBA-derived particles encapsulated in a double layer of graphene and polydopamine (PDA). The addition of graphene not only reduces the density of the derived material but also effectively disperses the CoFe@C@C nanocubes to prevent the generated highly conductive carbon layer from adhering to improve the impedance matching, as well as introduces a large number of heterogeneous interfaces to improve the loss capability. Thanks to which the CFCCG7 composites have a reflection loss of −66.33 dB and an effective microwave absorption frequency covering the entire Ku-band. This work provides a new approach for rational design of multilayer carbon structure-coated PBA-based microwave absorbing materials.

中文翻译：

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石墨烯气凝胶封装双碳壳CoFe@C@C纳米立方体用于构建高性能微波吸收材料

近年来，普鲁士蓝类似物（PBA）因其在高温热解后转变为介电/磁耦合复合材料并能够保持其基本形态而备受关注。然而，使用 PBA 设计高效的微波吸收材料仍然是一个挑战。本工作采用湿化学法制备了Co-Fe PBA，并通过搅拌自聚合和水热法制备了石墨烯气凝胶包裹的双碳壳CoFe@C@C纳米立方体（CFCCG），并在不同温度下进行热处理获得由封装在石墨烯和聚多巴胺（PDA）双层中的核壳结构 PBA 衍生颗粒组成的复合材料。石墨烯的添加不仅降低了衍生材料的密度，还可以有效分散CoFe@C@C纳米立方体，防止生成的高导电碳层粘附，提高阻抗匹配，同时引入大量异质界面以提高抗损能力。因此，CFCCG7复合材料的反射损耗为-66.33 dB，有效微波吸收频率覆盖整个Ku波段。该工作为合理设计多层碳结构涂层PBA基吸波材料提供了一种新方法。