Positive and Reverse Core/Shell Structure CoxFe3–xO4/MoS2 and MoS2/CoxFe3–xO4 Nanocomposites: Selective Production and Outstanding Electromagnetic Absorption Comprehensive Performance

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 Co x Fe 3– x O 4 /MoS 2 ( x = 1.5, 0.75 and 0.5) and MoS 2 /Co x Fe 3– x O 4 ( x = 0.5) nanocomposites were elaborately produced through an inexpensive two-step hydrothermal process. It was found that the Co x Fe 3– x O 4 /MoS 2 samples exhibited a much smaller optimal reflection loss (RL opt ) value and a broader frequency bandwidth ( f b ) with the lower value of matching thickness ( d m ) when the Co x Fe 3– x O 4 /MoS 2 loadings were raised to 60 from 30 wt %. With the x value decreasing from 1.5 to 0.5, the obtained Co x Fe 3– x O 4 /MoS 2 samples displayed a much smaller RL opt value with a thinner d m and a much larger f b value with the thin d m (∼2 mm). The sample consisting of 60 wt % Co x Fe 3– x O 4 /MoS 2 ( x = 0.5) exhibited an RL opt value of −66.83 dB with the d m of merely 1.57 mm, and its corresponding f b value could reach 6.64 GHz with the d m of 2.02 mm. Moreover, compared with the MoS 2 /Co x Fe 3– x O 4 ( x = 0.5) sample, the Co x Fe 3– x O 4 /MoS 2 ( x = 0.5) sample displayed evidently better microwave absorbing comprehensive performances in terms of low RL opt value, large f b value, and high chemical stability. Generally, the obtained results demonstrated that the designed Co x Fe 3– x O 4 /MoS 2 nanocomposites could act as MAs with outstanding comprehensive properties.