Preparation And Investigation Of Electromagnetic Wave Absorption Performance Of MoS₂-based Composites

The electronic technology with rapid development has brought great convenience to people’s production and life,such as mobile phones,computers and other communication tools.Meanwhile,electromagnetic waves endangered our health.In the military field,radar is widely used as a reliable technology to detect targets.Radar stealth has become an urgent problem to be solved for thesurvival of weapons.Electromagnetic wave absorbing materials have been widely used in humman’s life and military fields,because it can absorb electromagnetic waves by transforming them into thermal energy or other energy.There is desperate demand to investigate new-type absorbing materials with thin thickness,light weight,broad effective absorption bandwidth and strong absorption.In this paper,we have prepared MoS2 nanoparticles with different morphologies,MoS2/RGO nanocomposite and Co doped MoS2/RGO nanocomposite,and investigated the performance of electromagnetic wave absorption.It can be summed as follow:(1)The flake-shaped MoS2 and flower-shaped MoS2 nanoparticles were prepared by one-step hydrothermal method,and investigated the electromagnetic wave absorption properties of the two samples.Flower-shaped MoS2 nanoparticles have large specific surface area and complex structure,leading to enhance multiple scattering of electromagnetic wave,thus flower-shaped MoS2 nanoparticles have a better wave absorption performance than that of flake-shaped MoS2 nanoparticles.It was found that the samples consisting of 30 wt%flower-shaped MoS2 nanoparticles in the wax matrix based composites exhibited an effective electromagnetic wave absorption bandwidth of 7.6 GHz(10.32-17.92 GHz)with the thickness of 3.0 mm.The minimum RL value of-39.20 dB was observed at 17.60 GHz for the sample with a thickness of 2.4 mm.(2)The MoS2/RGO nanocomposites were compounded in order to increase the conductivity and the dielectric loss of MoS2.There is a higher conductivity for reduced graphene oxide to increase the conduction loss of the composite material,and enhanced the interface polarization.The electromagnetic wave absorption properties has been investigated for MoS2/RGO nanocomposites by adjusting the mass ratio of RGO and MoS2.The data indicate that the MoS2/RGO-I nanocomposites(the atomic ratio of Mo:C=1:4)has the best electromagnetic wave absorption properties in the four samples.The MoS2/RGO-1 exhibited a minimum RL value of-49.28 dB with the thickness of 2.7 mm,the effective electromagnetic wave absorption bandwidth of 6.57 GHz,and the thickness of 2.7 mm.(3)Co elements was successfully doped into MoS2/RGO nanocomposites by hydrothermal method.Because the doping of Co atoms regulates the electronic structure of MoS2,leading to an enhanced conductivity of MoS2,we synthesized.Co-MoS2/RGO nanocomposites by adjusting the amounts of Co element,and investigated the electromagnetic wave absorption properties.It can be found that the Co-MoS2/RGO-3 nanocomposites(the atomic ratio of Mo:Co=23:1)had the strongest absorbing performance.The sample had the minimum RL value of-54.48 dB observed at 10.4 GHz with a thickness of 3.9 mm and an effective electromagnetic wave absorption bandwidth of 4.8 GHz.The Co-MoS2/RGO-3 nanocomposites has the broadest effective electromagnetic wave absorption bandwidth of 7.42 GHz with the thickness of 3.0 mm.