Preparation And Microwave Absorbing Properties Of Two-dimensional MXene And RGO Hollow Structures

With the rapid development of modern technology,fifth generation（5G）wireless systems with optical transmission speed are driving the rapid development of electronic communication equipment,Global Positioning System and portable wearable technology,bring great convenience to people.However,the inevitable electromagnetic wave pollution caused by these devices will seriously affect human health,the normal work of electronic equipment and military security,etc..The new application environment requires the next generation of electromagnetic wave absorbing materials with thin thickness,light weight,wide frequency band and strong absorption performance,as well as the high temperature resistance,corrosion resistance,oxidation resistance and other special applications in the field of design and preparation of a huge challenge.In this study,the microstructure of two-dimensional material Ti₃C₂T_XMxene was controlled,MXene was prepared by wet chemical etching,and the lamellar structure of MXene was transformed into hollow structure by sacrificing polystyrene（PS）microsphere template method,the two-dimensional MXene nanoplates were transformed into a three-dimensional hollow structure with adjustable layer thickness.The invention not only improves the electromagnetic wave absorption ability,but also has the advantages of light weight,low density and the like.The influence of PS content on the microstructure and microwave absorbing properties of hollow MXene microsphere is studied.The optimum reflection loss is-53.8 d B when the load is 5%and the thickness of microwave absorbing layer is 1.8 mm,the effective absorption bandwidth is 2.2 GHz.In order to verify whether the above-mentioned micro-structure control method is also suitable for other two-dimensional materials,graphene oxide（GO）was prepared by Hummer’s method,the microstructure of reduced graphene oxide（rGO）was controlled by the same preparation method,and the related researches were carried out.The results show that the hollow structure rGO also has the best reflection loss of-33.4 d B and the effective absorption bandwidth of 4.3 GHz when the load is 5%and the thickness of absorbing layer is 1.2mm,it is proved that this method can be applied not only to the preparation of two-dimensional MXene hollow structure,but also to the preparation of two-dimensional rGO hollow structure.Two-dimensional materials MXene and rGO have great electromagnetic wave absorption potential,but their absorption ability is hindered by high dielectric constant and impedance mismatch.The loss mechanism of the hollow structure is analyzed by changing its loss capacity and impedance matching characteristics,and many factors affecting the absorbing performance of the hollow structure are determined.The hollow structure MXene and hollow structure rGO prepared by this method not only have the requirements of new wave absorbing materials,but also have the characteristics of low cost and simple preparation process,it provides a new idea and method for the research and exploration of new wave-absorbing materials.