Interfacial and defect polarization in MXene-like laminated spinel for electromagnetic wave absorption application

Manufacturing advanced absorbers is an effective way to deal with the greater electromagnetic pollution challenges associated with the application of 5G technology. While reasonable morphology design is an efficacious method to improve the absorption performance of the absorber. Herein, a series of Co-based spinel Co₃O₄/ACo₂O₄ (A = Ni, Cu, Zn) were successfully synthesized via a facile PVP-assisted hydrothermal method. It is worth mentioning that the Co₃O₄/ZnCo₂O₄ with MXene-like laminated structure was synthesized successfully for the first time (to our knowledge) by changing the type of elements in A position. The EAB of MXene-like laminated Co₃O₄/ZnCo₂O₄ absorber can reach 6.24 GHz (from 11.6 to 17.84 GHz) with a matching thickness of 2.62 mm. This excellent performance can be attributed to the multiple scattering, interfacial polarization, and polarization induced by lattice defects and oxygen vacancies (the dominant). This work offers a novel pattern for improving the EMW absorption ability of pure spinel by manufacturing MXene-like laminated Co-based spinel and adjusting annealing temperature reasonably.