The ZnO-doped magnetic graphene composite materials were prepared by a two-step hydrothermal method. The microstructures and compositions were characterized by scanning electron microscope, transmission electron microscope, X-ray diffractometer, and X-ray photoelectron spectroscopy. The electromagnetic properties were determined by vector network analyzer and vibrating sample magnetometer. The strengthening mechanism of absorbing properties was analyzed in combination with first-principles calculations. The results show that the ZnO sheets and Fe₃O₄ balls closely overlap under the ball-sheet and ball-ball interactions and form abundant micro-interfaces and cavity structures, enhancing the microwave absorbing property. The composite absorbing material reaches the minimum reflection loss of − 53.96 dB at 8.96 GHz with a thickness of 1.81 mm, and the effective absorbing band could be tun-able flexibly within the range of 5.2 ∼ 18 GHz by adjusting the matching thickness within the range of 0.84 ∼ 3.03 mm. First-principles calculations further demonstrate that the modification of ZnO greatly changes the electronic state and structure, reduces the energy barrier of electrons transferring, forms special charge transferring channels, increases the concentration of carriers, and improves the absorbing capacity of the material.

ZnO掺杂磁性石墨烯复合材料采用两步水热法制备。通过扫描电子显微镜、透射电子显微镜、X射线衍射仪和X射线光电子能谱仪对微观结构和成分进行了表征。电磁特性由矢量网络分析仪和振动样品磁力计测定。结合第一性原理计算分析了吸波性能的强化机理。结果表明，ZnO片材和Fe ₃ O ₄球片和球-球相互作用下紧密重叠，形成丰富的微界面和空腔结构，增强了微波吸收性能。复合吸波材料在8.96 GHz时达到-53.96 dB的最小反射损耗，厚度为1.81 mm，有效吸波带可在5.2 ∼ 18 GHz范围内灵活可调，通过在该范围内调整匹配厚度0.84 ∼ 3.03 毫米。第一性原理计算进一步表明，ZnO的改性极大地改变了电子状态和结构，降低了电子转移的能垒，形成了特殊的电荷转移通道，提高了载流子浓度，提高了材料的吸收能力。