Outstanding comprehensive performance versus facile synthesis: Constructing core and shell-interchangeable nanocomposites as microwave absorber.

It is still a great challenge to develop high-performance microwave absorption materials (MAMs). Herein, we first proved the excellent synergistic effect of Fe3O4/MoS2 heterostructure based on the theoretical calculations. To effectively utilize the synergistic effect and morphology, core and shell-interchangeable Fe3O4@MoS2 and MoS2@Fe3O4 nanocomposites (NCs) were elaborately constructed. By controlling the hydrothermal temperature, different MoS2 morphologies and contents of Fe3O4@MoS2 NCs were produced, which simultaneously displayed the optimal reflection loss (RL) values (~-50 dB), broad absorption bandwidth (⩾5.0GHz) and high chemical stabilities. With the synthesis temperature increasing from 170 °C to 200 °C, their outstanding microwave absorption (MA) capabilities moved towards the high frequency region and thin matching thickness. Impressively, the Fe3O4@MoS2 obtained at 200 °C presented a minimum RL value of -50.75 dB with the thickness of 2.90 mm and an absorption bandwidth of 5.0 GHz with the thickness of 1.71 mm, and the excellent MA capabilities (RL values <-30 dB) with the low matching thicknesses (<2 mm) could be observed in the frequency range of X and Ku bands. Moreover, compared to the reverse structure MoS2@Fe3O4, the core@shell structure Fe3O4@MoS2 exhibited evidently superior MA comprehensive properties in terms of low optimal RL value, broad absorption bandwidth and high chemical stability, which could be ascribed to the improved impedance matching and microwave attenuation characteristics. Generally, the proposed flower-like core@shell structure Fe3O4@MoS2 NCs presented very extraordinary MA comprehensive properties, which were very attractive candidates for high-performance MAMs.