Rational design of flower-like core–shell Fe3O4@SiO2@MoSe2 composites for high performance electromagnetic wave absorption

Transition metal dichalcogenides (TMDCs) are considered to have remarkable electromagnetic (EM) wave attenuation due to their perfect dielectric property and graphene-like structure, but they still often fail to function due to impedance mismatch problems. Here, using a multilayer coating strategy, we prepared flower-like Fe3O4@SiO2@MoSe2 absorbers with core–shell structure. SiO2 can form the Fe3O4-SiO2 and SiO2-MoSe2 heterogeneous interfaces when it is applied to the Fe3O4 surface as an impedance matching layer in the Fe3O4@SiO2@MoSe2 composite, increasing the interfacial polarization loss to the absorber. In addition, Fe3O4@SiO2 as a magnetic core also reduces the relative density of the substance compared to Fe3O4. Products with the absorption performance of various electromagnetic waves were produced by varying the amount of magnetic components (Fe3O4@SiO2) in the absorber. With a minimal reflect loss (RL) of − 51.86 dB and an effective absorption bandwidth (EAB, RL < -10 dB) of 4.96 GHz at a matching thickness of 1.8 mm, the Fe3O4@SiO2@MoSe2 (sample S3) demonstrated exceptional properties in EM wave absorption. In addition, we synthesized Fe3O4@MoSe2 and determined its RL value and maximum EAB (EABmax) in order to highlight the significance of the impedance matching layer SiO2. Fe3O4@MoSe2 appears to perform less well than Fe3O4@SiO2@MoSe2 in terms of EM wave absorption, with a minimal RL value of -50.20 dB and an EABmax of only 2.00 GHz at the matching thickness of 4.8 mm. The remarkable properties in EM wave absorption of Fe3O4@SiO2@MoSe2 is the result of the combined effect from impedance match and loss mechanisms of various compositions, so the component SiO2 has a non-negligible function as an impedance matching layer. This study has blazed the trail for developing the lightweight and excellent performance of absorbers.