Tunable and improved microwave absorption of flower-like core@shell MFe2O4@MoS2 (M = Mn, Ni and Zn) nanocomposites by defect and interface engineering

Previous results revealed that the defect and/or interface had a great impact on the electromagnetic parameters of materials. In order to understand the main physical mechanisms and effectively utilize these strategies, in this study, MFe2O4 and flower-like [email protected] MFe2O4@MoS2 (M = Mn, Ni, and Zn) samples with different categories were elaborately designed and selectively produced in large scale through a simple two-step hydrothermal reaction. We conducted the systematical investigation on their microstructures, electromagnetic parameters and microwave absorption performances (MAPs). The obtained results revealed that the large radius of M2+ cation could effectively boost the concentration of oxygen vacancy in the MFe2O4 and MFe2O4@MoS2 samples, which resulted in the improvement of dielectric loss capabilities and MAPs. Furthermore, the introduction of MoS2 nanosheets greatly improved the interfacial effect and enhanced the polarization loss capabilities, which also boosted the MAPs. By taking full advantage of the defect and interface, the designed MFe2O4@MoS2 samples displayed tunable and excellent comprehensive MAPs including strong absorption capability, wide absorption bandwidth and thin matching thicknesses. Therefore, the clear understanding of defect and interface engineering made these strategies well elaborately designed and applicable to improving MAPs.