Wang Xiangyu, Liao Jun, Du Rongxiao, Wang Guohui, Tsidaeva Natalia, Wang Wei
Department of Physics and Electronics, School of Mathematics and Physics, Beijing University of Chemical Technology, Beijing 100029, China.
Natural Sciences Research and Education Center, North-Ossetian State University, Vladikavkaz 363517, Russia.
J Colloid Interface Sci. 2021 May 15;590:186-198. doi: 10.1016/j.jcis.2021.01.069. Epub 2021 Jan 27.
A unique three-dimension (3D) porous network structure where N-doped reduced graphene oxide aerogels (N-rGA) are decorated by raspberry-like CoFeO (CFO) clusters. Super-broad effective microwave absorption bandwidth (7.28 GHz) of the CFO/N-rGA composite is obtained at 2.53 mm by changing N contents. Here, the dipolar relaxation loss and conduction loss are highly sensitive to the presence of pyridinic, pyrrolic and graphitic N in the CFO/N-rGA composites. A minimum reflection loss of the CFO/N-rGA composites reaches up to -55.43 dB at 15.36 GHz with a matching thickness (2.3 mm) and low filler loading (10 wt%). Its effective absorption bandwidth completely covers X-band from 7.76 to 12.72 GHz at 3.3 mm. The high-efficiency microwave absorption of the composites mainly results from the enhanced polarization relaxation, the specific design of conductive network and the superior impedance matching. This study offers a promising technical route to explore new N-doped magnetic/dielectric composites as ideal microwave absorbers.
一种独特的三维（3D）多孔网络结构，其中氮掺杂还原氧化石墨烯气凝胶（N-rGA）被覆盆子状的CoFeO（CFO）簇修饰。通过改变氮含量，CFO/N-rGA复合材料在2.53毫米处获得了超宽的有效微波吸收带宽（7.28吉赫兹）。在此，偶极弛豫损耗和传导损耗对CFO/N-rGA复合材料中吡啶型氮、吡咯型氮和石墨型氮的存在高度敏感。CFO/N-rGA复合材料的最小反射损耗在15.36吉赫兹时达到-55.43分贝，匹配厚度为2.3毫米，填料负载量低（10重量%）。其有效吸收带宽在3.3毫米时完全覆盖7.76至12.72吉赫兹的X波段。复合材料的高效微波吸收主要源于增强的极化弛豫、导电网络的特殊设计以及优异的阻抗匹配。本研究为探索新型氮掺杂磁性/介电复合材料作为理想微波吸收剂提供了一条有前景的技术路线。
