Synthesis Of MXene Complex And Its Application In Microwave Absorption

Electromagnetic interference and radiation have caused serious environmental pollution,which is extremely harmful to electromagnetic compatibility,human health and daily communication.For many years,researchers have utilized a variety of two-dimensional materials to prepare broadband,efficient,and lightweight absorbing materials to solve the above problem.Among them,Ti₃C₂T_x MXene is a kind of material with great potential in the application of microwave absorption?MA?due to its two-dimensional characteristics,high dielectric loss,and rich surface functional groups.Limited by the shortcomings such as insufficient magnetic loss and narrow absorption band,there is a long way to go for Ti₃C₂T_x to be applied in the microwave absorption market.In this thesis,the related structural design and absorbing mechanism research are carried out in response to the above problems.CoFe@Ti₃C₂T_x composite with sandwich structure was designed for MA to improve the magnetic loss and expand absorption band.After DMF intercalation,magnetic CoFe flakes could be in-situ reduced using hydrazine hydrate,etc.The obtained CoFe@Ti₃C₂T_x composite exhibited a minimum reflection loss?RL?value of-34.93 dB at the frequency of10.96 GHz,while the thickness was only 1.7 mm,the effective absorption band width covered from 10.32 GHz to 12.96 GHz.Compared with the pure Ti₃C₂T_x,CoFe@Ti₃C₂T_x had greatly improved the absorption intensity and frequency bandwidth.The enhanced MA ability of CoFe@Ti₃C₂T_x should be attributed to the unique sandwich-like structure,good impedance matching characteristics and enhanced interfacial polarization.In addition,when the CoFe@Ti₃C₂T_x coating is applied on aluminum plate and fabric substrate,it showed good heat dissipation property from thermal infrared image analysis.Based on the fact that Ti₃C₂T_x surface is susceptible to be oxidized to TiO₂,this work proposed to utilize Ti₃C₂T_x as precursor to rapidly and directly generate bipyramid TiO₂ by microwave digestion method.The growing mechanism and influencing factors of different morphologies were discussed,and the Ni/TiO₂/C with heterostructure was successfully prepared.Due to the synergistic effect of dielectric loss,magnetic loss,and unique heterogeneous nanostructure,Ni/TiO₂/C achieved a minimum RL of-39.91 dB at 16.93GHz,while the thickness was only 1.4 mm.Besides,the oxidation method through microwave digestion could also be promoted in other precursor MXenes to prepare their corresponding 2D transitional metal oxides?TMO-MX?.