Construction And Microwave Absorption Properties Of Fe₃O₄/FeS_x-GO Aerogel

The rapid development of radio communication and electronic products not only brings a lot of convenience to our lives,but also causes electromagnetic interference and pollution problems.Therefore,in order to solve the current electromagnetic interference and pollution problems,the development of high absorption,low thickness,wide band and light weight absorbing materials has become one of the current research hotspots.Materials such as transition metal oxides or sulfides can be used to absorb electromagnetic waves,and they are cheap,stable and simple to manufacture.However,they are easy to agglomerate in the process of preparation and have poor electrical conductivity,which limits their application in the field of electromagnetic wave absorption.Graphene aerogel has the characteristics of unique three-dimensional network shape,abundant pores,good electrical and thermal conductivity and high mechanical strength,which makes it have potential application value in various fields.However,when graphene aerogel is used as a wave absorbing material,it has some disadvantages such as poor impedance matching and single loss mechanism.For nanomaterials,structure has a crucial effect on their properties.Among them,the hollow nanostructure usually has a large specific surface area and a low mass density,so that it has a broad application prospect in lithium batteries,catalysis,biomedics,electromagnetic absorption and other fields.Therefore,aerogels with hollow structure ferrioxide/Ferrisulfide graphene oxide（Fe₃O₄/Fe S_x-GO）were synthesized by template method,hydrothermal method and high temperature heat treatment,and the wave absorption properties and mechanism of these materials as electromagnetic wave absorbers were studied in detail.The main research contents are as follows:Firstly,the sample was characterized by scanning,transmission and X-ray diffraction（XRD）,which proved that the hollow structure and aerogel structure were successfully synthesized.The results of electromagnetic wave absorption test show that the aerogel obtained by mixing with graphene oxide at 400℃has the best performance.When the addition amount is 30 wt%and the thickness is 2.0 mm,the minimum reflection loss value reaches-43.03 d B,and the maximum effective absorption bandwidth reaches 4.24 GHz when the thickness is 1.6 mm.The excellent electromagnetic wave absorption performance of Fe₃O₄/Fe S_x-GO aerogel is the result of the joint action of the hollow structure,three-dimensional network structure and heterogeneous interface of the composite material.In summary,this paper successfully prepared a new wave absorbing material with the characteristics of"thin,light,wide and strong"through the multiple regulation of composition,crystallization degree and structure.The composite material has a good application prospect in the field of electromagnetic wave absorption,and can also provide a reference for the preparation of other new electromagnetic wave absorbing materials.