Preparation And Microwave Absorption Properties Of CoS/MnSO₄ Micro-nano Heterostructures

With the rapid development of electronic information technology,these electromagnetic applications not only bring great convenience to human life,but also bring electromagnetic radiation,electromagnetic interference and other issues.In addition to the military demand for radar stealth technology,electromagnetic wave absorbing materials have become a research hotspot in today’s society.Semiconductor metal sulfide is a kind of high-quality microwave absorbing material,which has excellent photoelectric performance,good stability and environmental friendliness,and has a broad application prospect in the field of absorbing materials.At present,researchers focus on the research of single metal sulfide absorbing materials,and there are few reports on the multi metal composite sulfide.For nano materials,morphology and structure have a great influence on their performance.Hollow structure has a great research value in catalysis,energy,electromagnetic wave absorption and other fields because of its large specific surface area and low density.In the absorbing materials,the heterojunction structure composed of different materials can have more material interfaces,which can make the materials have more interface polarization,so as to improve the absorbing properties of the materials.Therefore,the microwave absorbing materials of CoS/MnSO4 micro-nano heterostructures with hollow flower-like microsphere structure were prepared.The microwave absorbing properties of the materials were compared with those of the monometallic sulfide in detail,and the microwave absorbing mechanism was discussed.These,CoS/MnSO4 micro-nano heterostructures(Co-Mn-S),cobalt sulfide(Co-S)and MnSO4(Mn-S)were prepared by solvothermal method.The materials were characterized by XRD,XPS,SEM and TEM.The results show that the CoS/MnSO4 micro-nano heterostructures is a hollow flower-like microsphere composed of CoS and MnSO4·5H2O nanoparticles,and the morphology of cobalt sulfide is similar,while the Mn-S is composed of irregular particles,and the main component is MnSO4·5H2O.Compared with the three sulfides,the Co-Mn-S have the best microwave absorption performance,the largest real part and imaginary part of complex permittivity,good impedance matching and the highest attenuation coefficient.At the thickness of 2.0 mm and 30 wt%,the minimum reflection loss of Co-Mn-S is-48.0 dB,and the effective absorption bandwidth is 3.8 GHz.At the thickness of 1.7 mm,the maximum effective absorption bandwidth is 4.3 GHz.In contrast,the absorption performance of Co-S and Mn-S is poor.At the thickness of 1.5 mm-4.5 mm,the minimum reflection loss of Co-S is greater than-10 dB,while that of Mn-S is only-2.3 dB.The excellent microwave absorbing properties of Co-Mn-S are related to its hollow structure and heterostructures composition.The hollow structure can reduce the density of the material and have more edge active sites.These active sites can be used as the polarization center,which is conducive to the dielectric loss of the material.Heterostructures composition can increase the conductivity of the material,improve the conduction loss,and different material interfaces can form interface polarization,enhance the electromagnetic wave loss ability of the materialThe CoS/MnSO4 micro-nano heterostructures was prepared by a simple method.It has the characteristics of strong absorption,wide frequency band,thin thickness and small density and has a great application prospect in the field of microwave absorption.The heterostructure composition and hollow structure of the materials also provide new ideas for the study of metal sulfide absorbing materials.