Positive and Reverse Core/Shell Structure Co_<i>x</i>Fe_3–<i>x</i>O₄/MoS₂ and MoS₂/Co_<i>x</i>Fe_3–<i>x</i>O₄ Nanocomposites: Selective Production and Outstanding Electromagnetic Absorption Comprehensive Performance

Abstract

Lots of research have focused on the core/shell structure nanocomposites owing to their synergistic effect that were considered as the most promising high-performance microwave absorbers (MAs). However, the excellent comprehensive properties of MAs are still in urgent need. Herein, positive and reverse core/shell structure CoxFe3–xO4/MoS2 (x = 1.5, 0.75 and 0.5) and MoS2/CoxFe3–xO4 (x = 0.5) nanocomposites were elaborately produced through an inexpensive two-step hydrothermal process. It was found that the CoxFe3–xO4/MoS2 samples exhibited a much smaller optimal reflection loss (RLopt) value and a broader frequency bandwidth (fb) with the lower value of matching thickness (dm) when the CoxFe3–xO4/MoS2 loadings were raised to 60 from 30 wt %. With the x value decreasing from 1.5 to 0.5, the obtained CoxFe3–xO4/MoS2 samples displayed a much smaller RLopt value with a thinner dm and a much larger fb value with the thin dm (∼2 mm). The sample consisting of 60 wt % CoxFe3–xO4/MoS2 (x = 0.5) exhibited an RLopt value of −66.83 dB with the dm of merely 1.57 mm, and its corresponding fb value could reach 6.64 GHz with the dm of 2.02 mm. Moreover, compared with the MoS2/CoxFe3–xO4 (x = 0.5) sample, the CoxFe3–xO4/MoS2 (x = 0.5) sample displayed evidently better microwave absorbing comprehensive performances in terms of low RLopt value, large fb value, and high chemical stability. Generally, the obtained results demonstrated that the designed CoxFe3–xO4/MoS2 nanocomposites could act as MAs with outstanding comprehensive properties.