Hollow engineering of HCNs@CoFe 2 Se 4 -QDs with quantum dots toward ultra-broadband electromagnetic wave absorption

Hollow engineering is considered to be an essential subfield in promoting electromagnetic (EM) wave absorption intensity and realizing the lightweight characteristics. However, the enhancement of effective absorption bandwidth (EAB) still faces huge challenges. Herein, HCNs@CoFe2Se4-QDs with superior EM wave absorption intensity and ultra-broadband EAB are produced by using tightly arranged SiO2 spheres as the hard-templates. Specifically, the removal of SiO2 templates inevitably results in the formation of hollow cavity, which is favorable to optimize the impedance matching and increase the absorption intensity. Besides, the incorporation of selenium powder effectively increases the numbers of heterogeneous…