Preparation And Microwave Absorption Properties Of The ZnFe₂O₄@C/RGO Composites With Core-shell Structure

The purpose of this paper is to prepare the absorbing materials with“thin thickness,light weight,wide absorption band and strong absorption capacity”.Through the construction of a special structure,the absorbing properties of the material are improved.Hollow ZnFe₂O₄ and resorcinol were carbonized and reduced to form hollow ZnFe₂O₄@C composite with core shell structure,and the changes of absorbing properties before and after coating were studied.Hollow ZnFe₂O₄@C composite material with excellent absorbing properties were selected to be compounded with graphene with good dielectric loss to construct a three-dimensional conductive network structure and study its absorbing properties.The main conclusions are as follows:?1?Using polyethylene glycol as a soft template,ZnFe₂O₄ nanoparticles with hollow structure were successfully synthesized by hydrothermal method.Hollow ZnFe₂O₄ was formed because polyethylene glycol was used as a soft template,so that fine ZnFe₂O₄ particles were self-assembled into ZnFe₂O₄ with a hollow structure in an orderly manner.The results show that:The diameter of the prepared hollow ZnFe₂O₄ is about 100 nm,and the dispersion is good.The hollow ZnFe₂O₄ exhibits excellent absorption performance.When the matching thickness is 2.7 mm,the minimum reflection loss value reach-42.18 dB at 12.38 GHz.When the matching thickness is 3.0 mm,the frequency band with the reflection loss value less than-10 dB?absorption rate is 90%?is the widest,2.60 GHz?10.60 GHz¹3.20 GHz?.?2?Hollow ZnFe₂O₄ was carbon-coated with resorcinol as a carbon source,and a hollow ZnFe₂O₄@C composite material with a core-shell structure?hollow ZnFe₂O₄ as the core and C as the shell?.was successfully prepared and synthesized.The results show that:compared with hollow ZnFe₂O₄,hollow ZnFe₂O₄@C has better absorbing properties.Hollow ZnFe₂O₄@C achieves the minimum reflection loss value?-51.4 dB?at a thickness of 2.0 mm and a frequency of 15.4 GHz;and when the matching thickness is 2.2 mm,the absorption bandwidth with the reflection loss value below-10 dB is 4.10 GHz?12.6¹6.7 GHz?.?3?The hollow ZnFe₂O₄@C/RGO composite was successfully prepared by hydrothermal method,and the mass ratio of hollow ZnFe₂O₄@C and RGO was investigated to some extent.The results show that:when the mass ratio of hollow ZnFe₂O₄@C and RGO is 10:1,the composite composite has the best comprehensive absorption performance.When the thickness is 1.9 mm,the minimum reflection loss is-44.4 dB at a frequency of 10.7 GHz,the frequency band whose reflection loss value is lower than-10 dB is 2.9 GHz?9.5¹2.4 GHz?.