Synthesis And Electromagnetic Wave Absorption Performance Of WSe₂-based Nanocomposites

With the development of various electronic devices,electromagnetic wave radiation has an increasingly serious impact on human health and the normal operation of precision instruments.Electromagnetic（EM）wave absorbers can fundamentally eliminate the problems of electromagnetic radiation and electromagnetic interference.However,electromagnetic wave absorbers usually can only absorb electromagnetic waves in a single frequency band,which limit their application.Therefore,it is still a challenge to develop electromagnetic wave absorbing materials with strong absorption and multi-band EM wave absorption.In this paper,the electromagnetic wave absorption properties of WSe₂-based nanomaterials were reported.WSe₂@CNTs nanocomposites were synthesized by using one-step solvothermal method,which overcomes the disadvantages of poor conductivity and impedance mismatch of WSe₂itself.The electromagnetic properties and electromagnetic wave absorption properties of the nanocomposites can be effectively tuned by changing the mixing ratio of WSe₂and CNTs,and the electromagnetic wave absorption frequency band can be up to three bands.The reflection loss（RL）of WSe₂@CNTs can reach-60.1 d B,and the effective absorption bandwidth can reach4.24 GHz.The excellent electromagnetic wave absorption performance is mainly attributed to the conductance loss and multiple relaxations,as well as their synergistic effect.This result indicates that WSe₂@CNTs nanocomposites are potential candidates for high-efficiency electromagnetic wave absorbing materials and provides a valuable route for designing high-performance electromagnetic wave absorbing materials in the future.The ideal microwave absorption material requires the characteristics of high efficiency,lightweight,broadband absorption,and multi-band absorption.According to previous studies,introducing Co₃O₄nanoparticles to certain materials has been proved to be an effective method leading to good EM wave absorption properties.In this work,the obtained WSe₂@CNTs/Co₃O₄nanocomposites exhibit multi-band EM absorption capability.The maximum reflection loss of-51.35 d B occurs at 13.52 GHz and effective bandwidth below-10 d B can reach 4.64 GHz.Meanwhile,by optimizing the content of Co₃O₄and the thickness of the absorber,the absorption bandwidth can be effectively adjusted to achieve multi-band absorption.