Study On Preparation And Electromagnetic Properties Of Ti₃C₂T_X/rGO/Fe₃O₄ Composite Materials

Facing the complex electromagnetic environment,designing and preparing new microwave absorption materials（MAMs）is one of the most feasible ways to achieve civil electromagnetic protection and military radar stealth.Two-dimensional nanomaterials such as graphene and MXene have significant advantages in the development of high-efficiency MAMs due to their inherent high conductivity,unique layered structure,and easy-to-modify chemically active surface.In this thesis,graphene oxide and Ti₃C₂T_xMXene are the main research objects.Firstly,a binary composite aerogel with a three-dimensional porous structure was constructed under solvothermal conditions,and then magnetic Fe₃O₄nanoparticles were introduced into the pores to prepare ternary composite aerogels,the absorbing properties and mechanism of binary or ternary composite aerogels are systematically analyzed.The main research contents and conclusions are as follows:（1）Mono or few-layered Ti₃C₂T_xMXene nanosheets was obtained by selectively etching the Al atomic layer in the Ti₃Al C₂precursor with a HCl-LiF reaction system.When the sample filling amount is 30 wt%,the minimum reflection loss value can reach-11.7 d B at 8.7GHz with a matching thickness of 3.0 mm,and the effective absorption bandwidth reaches1.2 GHz（8.2-9.4 GHz）.The conductivity loss caused by the conductive properties after etching,and the dielectric polarization relaxation loss caused by surface functional groups and defects are the keys to the improvement of its microwave absorption properties.（2）Taking advantage of the strong gelation ability of graphene oxide,Ti₃C₂T_x/r GO composite aerogels were formed by spontaneously constructing the interaction between graphene oxide and Ti₃C₂T_xMXene under solvothermal conditions.In order to obtain better absorbing performance,the electromagnetic parameter such as the amount of Ti₃C₂T_xis optimized.When the mass ratio of GO and Ti₃C₂T_xis 3:2 and the sample filling amount is 8wt%,the minimum reflection loss value can reach-39.6 d B at 10.4 GHz with a matching thickness of 2.0 mm,The effective absorption bandwidth reaches 3.2 GHz（12.5-15.7 GHz）with a matching thickness of 1.5 mm.The enhanced microwave absorbing performance are closely related to extended propagation path,highly conductive network,interface polarization and dipole polarization.（3）In order to improve the impedance matching performance and broaden the effective absorption bandwidth,Fe₃O₄nanoparticles were introduced when constructing Ti₃C₂T_x/r GO composite aerogels.When the mass ratio of GO,Ti₃C₂T_xand Fe₃O₄is 3:2:4,and the sample filling amount is 10 wt%,the minimum reflection loss value can reach-44.2 d B at 14.8 GHz with a matching thickness of 2.0 mm,the effective absorption bandwidth reaches 5.6 GHz（12.4-18.0 GHz）.The synergistic effect of dielectric loss（Ti₃C₂T_x,r GO）and magnetic loss（Fe₃O₄）further strengthen the microwave absorption performance of the composite aerogel.