Composite materials that combine magnetic and dielectric losses offer a potential solution to enhance impedance match and significantly improve microwave absorption. In this study, Co₃O₄/ZnCo₂O₄ and ZnCo₂O₄/ZnO with varying metal oxide compositions are successfully synthesized, which are achieved by modifying the ratios of Co²⁺ and Zn²⁺ ions in the CoZn bimetallic metal–organic framework (MOF) precursor, followed by a high-temperature oxidative calcination process. Subsequently, a layer of polypyrrole (PPy) is coated onto the composite surfaces, resulting in the formation of core–shell structures known as Co₃O₄/ZnCo₂O₄@PPy (CZCP) and ZnCo₂O₄/ZnO@PPy (ZCZP) composites. The proposed method allows for rapid adjustments to the metal oxide composition within the inner shell, enabling the creation of composites with varying degrees of magnetic losses. The inclusion of PPy in the outer shell serves to enhance the bonding strength of the entire composite structure while contributing to conductive and dielectric losses. In specific experimental conditions, when the loading is set at 50 wt%, the CZCP composite exhibits an effective absorption bandwidth (EAB) of 5.58 GHz (12.42 GHz-18 GHz) at a thickness of 1.53 mm. Meanwhile, the ZCZP composite demonstrates an impressive minimum reflection loss (RL_min) of −71.2 dB at 13.04 GHz, with a thickness of 1.84 mm. This study offers a synthesis strategy for designing absorbent composites that possess light weight and excellent absorptive properties, thereby contributing to the advancement of electromagnetic wave absorbing materials.

结合了磁损耗和介电损耗的复合材料为增强阻抗匹配和显着提高微波吸收提供了潜在的解决方案。本研究成功合成了不同金属氧化物组成的Co ₃ O ₄ /ZnCo ₂ O ₄和ZnCo ₂ O ₄ /ZnO，这是通过改变CoZn双金属中Co ²⁺和Zn ²⁺离子的比例来实现的。–有机骨架（MOF）前体，然后进行高温氧化煅烧过程。随后，将一层聚吡咯（PPy）涂覆到复合材料表面，形成核壳结构，称为Co ₃ O ₄ /ZnCo ₂ O ₄ @PPy（CZCP）和ZnCo ₂ O ₄ /ZnO@PPy （ZCZP）复合材料。所提出的方法允许快速调整内壳内的金属氧化物成分，从而能够创建具有不同程度磁损耗的复合材料。外壳中包含 PPy 可增强整个复合结构的粘合强度，同时有助于降低导电和介电损耗。在特定的实验条件下，当负载量设置为50 wt%时，CZCP复合材料在1.53 mm的厚度下表现出5.58 GHz（12.42 GHz-18 GHz）的有效吸收带宽（EAB）。同时，ZCZP 复合材料在 13.04 GHz 下表现出令人印象深刻的最小反射损耗 (RL _min ) -71.2 dB，厚度为 1.84 mm。这项研究为设计具有轻质和优异吸收性能的吸收复合材料提供了一种合成策略，从而有助于电磁波吸收材料的进步。