锌钴双金属普鲁士蓝类似物/还原氧化石墨烯复合材料的制备与吸波性能的研究

Preparation and Electromagnetic Wave-Absorbing Properties of Zinc-Cobalt Bimetallic Prussian Blue Analogue/Reduced Graphene Oxide Composites

摘要:

随着无线通信技术进入5G阶段，人们的生活变得更加便利。然而，无线通信带来的电磁波污染对电子产品的干扰及对人们身体健康的危害不容忽视。为了解决这一问题，科学家致力于研发质量轻、厚度薄、吸收电磁波频率范围宽和吸波能力强的电磁波吸收材料。普鲁士蓝类似物(PBA)作为金属有机框架(MOF)之一，有着成分可调、容易制备等特点，目前在微波吸收领域已经成为了研究热点。由于单一MOF无法构建导电网络，限制了其在吸波领域中应用，将MOF与低维材料复合是解决该问题的有效策略。基于此，采用共沉淀法初步合成锌钴双金属PBA，再以该类似物和氧化石墨烯(GO)作为前驱体，通过简单的水热反应、冷冻干燥及热处理工艺，成功合成了锌钴双金属普鲁士蓝类似物/还原氧化石墨烯（ZnO/CoO/Co@rGO）气凝胶复合材料。ZnO/CoO/Co@rGO气凝胶复合材料以三维还原氧化石墨烯(rGO)气凝胶为骨架，锌钴双金属PBA衍生的ZnO/CoO/Co复合物负载骨架之上，克服了单一MOF无法产生导电网络的问题，同时还降低了材料的密度，提升了阻抗匹配。ZnO/CoO/Co@rGO气凝胶复合材料的电磁参数，可以通过改变锌钴双金属PBA和GO的质量比进行调控。在锌钴双金属PBA与GO的质量比为3∶1，且ZnO/CoO/Co@rGO气凝胶复合材料与石蜡质量比仅为1∶9的情况下，该复合材料在频率2—18 GHz下展示了良好的微波吸收性能，最小反射损耗达到-54.5 dB，而最大有效吸收带宽为6.38 GHz。证明，ZnO/CoO/Co@rGO是一种具有潜力的微波吸收材料，进一步拓宽了MOF基吸波材料的研究范围。（专精特新·电磁波吸收与屏蔽用新型材料的研究进展专辑十二之十二）

Abstract:

As wireless communication technology enters the 5G stage， human life has become more convenient. However， the interference of electromagnetic wave pollution caused by wireless communication to electronic products and the harm to human health cannot be ignored. To solve this problem， scientists are committed to research and development of electromagnetic wave absorbing materials that are light in mass， thin in thickness， absorb a wide range of electromagnetic wave frequencies and have a strong electromagnetic wave absorbing ability. Prussian blue analogue （PBA）， as one of the metal-organic frameworks （MOF）， has the characteristics of adjustable composition and facile preparation， and has become a hot spot in the field of microwave absorption. However， the inability of a single MOF to construct a conductive network limits the application of MOFs in the field of microwave absorption， and combining MOFs with low-dimensional materials is an effective strategy to cope with this problem. Based on the strategy， in this paper， ZnCo-bimetallic PBA was first synthesized by co-precipitation， and then ZnO/CoO/Co@rGO aerogel composites were successfully synthesized by a simple hydrothermal reaction， freeze-drying， and heat treatment using the analogue and graphene oxide （GO） as precursors. Experimental results show that the ZnO/CoO/Co@rGO aerogel composites take three-dimensional reduced graphene oxide （rGO） aerogel as the skeleton， on which the ZnO/CoO/Co composites derived from ZnCo-bimetallic PBA are loaded. It overcomes the problem that a single MOF is unable to generate a conductive network， which improves the impedance matching and reduces the material density. The electromagnetic parameters of the ZnO/CoO/Co@rGO aerogel composites can be adjusted by changing the mass ratio of the ZnCo-bimetallic PBA and GO. When the mass ratio of the ZnCo-bimetallic PBA to the GO is 3∶1 and the mass ratio of the ZnO/CoO/Co@rGO aerogel composite to paraffin is only 1∶9， the ZnO/CoO/Co@rGO aerogel composite exhibits good microwave absorption properties in the frequency range of 2—18 GHz with a minimum reflection loss of -54.5 dB， while the maximum effective absorption bandwidth is 6.38 GHz， which proves it to be a promising microwave absorbing material and further expands the research on MOF-based microwave absorbing materials.