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 Fe 3 O 4 @SiO 2 @MoSe 2 absorbers with core–shell structure. SiO 2 can form the Fe 3 O 4 -SiO 2 and SiO 2 -MoSe 2 heterogeneous interfaces when it is applied to the Fe 3 O 4 surface as an impedance matching layer in the Fe 3 O 4 @SiO 2 @MoSe 2 composite, increasing the interfacial polarization loss to the absorber. In addition, Fe 3 O 4 @SiO 2 as a magnetic core also reduces the relative density of the substance compared to Fe 3 O 4 . Products with the absorption performance of various electromagnetic waves were produced by varying the amount of magnetic components (Fe 3 O 4 @SiO 2 ) 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 Fe 3 O 4 @SiO 2 @MoSe 2 (sample S3) demonstrated exceptional properties in EM wave absorption. In addition, we synthesized Fe 3 O 4 @MoSe 2 and determined its RL value and maximum EAB (EAB max ) in order to highlight the significance of the impedance matching layer SiO 2 . Fe 3 O 4 @MoSe 2 appears to perform less well than Fe 3 O4@SiO 2 @MoSe 2 in terms of EM wave absorption, with a minimal RL value of -50.20 dB and an EAB max of only 2.00 GHz at the matching thickness of 4.8 mm. The remarkable properties in EM wave absorption of Fe 3 O 4 @SiO 2 @MoSe 2 is the result of the combined effect from impedance match and loss mechanisms of various compositions, so the component SiO 2 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.