A novel three-dimensional composite of reduced graphene oxide sheets and porous LiFe₅O₈ microspheres was fabricated via a facile, green, and highly tunable strategy, and the microstructure, composition, and microwave-absorbing performances of the rGO/porous LiFe₅O₈ composite were characterized and investigated. The experimental results indicate that the porous LiFe₅O₈ microspheres are dispersed on the thin rGO sheets uniformly. Compared with the pure LiFe₅O₈ particles and porous LiFe₅O₈ microspheres, the as-prepared rGO/porous LiFe₅O₈ composites exhibit outstanding microwave-absorbing performances including efficient bandwidth and reflection loss. The rGO/porous LiFe₅O₈ composite (S-50) displays a maximum reflection loss of −53.4 dB at 12.2 GHz with a coating layer thickness of 2.2 mm and a broad effective bandwidth of 3.5 GHz (from 10.4 to 13.9 GHz). The outstanding microwave-absorbing performances are assigned to employing magnetic microflowers with multi-interfaces to improve impedance matching, which is ascribed to strong relaxation loss, electrical loss, and magnetic loss. This further confirms that the rGO/porous LiFe₅O₈ composites could be potential candidates for lightweight microwave-absorbing materials.

中文翻译：

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多孔LiFe ₅ O ₈微球复合还原氧化石墨烯的合成，表征及电磁波吸收性能

通过一种简便，绿色和高度可调的策略，制备了还原的氧化石墨烯片和多孔LiFe ₅ O ₈微球的新型三维复合材料，以及rGO /多孔LiFe ₅ O的微观结构，组成和微波吸收性能_对8种复合材料进行了表征和研究。实验结果表明，多孔LiFe ₅ O ₈微球均匀地分散在rGO薄板上。与纯LiFe ₅ O ₈颗粒和多孔LiFe ₅ O ₈微球相比，制备的rGO /多孔LiFe ₅ O ₈复合材料具有出色的微波吸收性能，包括有效的带宽和反射损耗。rGO /多孔LiFe ₅ O ₈复合材料（S-50）在12.2 GHz时具有-53.4 dB的最大反射损耗，涂层厚度为2.2 mm，有效带宽为3.5 GHz（从10.4至13.9 GHz）。出色的微波吸收性能被指定为使用具有多个界面的磁性微花来改善阻抗匹配，这归因于强大的弛豫损耗，电损耗和磁损耗。这进一步证实rGO /多孔LiFe ₅ O ₈复合材料可能是轻质微波吸收材料的潜在候选者。