Hierarchical MnO₂ nanosheets decorated on hollow co/N-doped carbon toward superior electromagnetic wave absorption

Hierarchical construction and hetero-interfaces design are considered as the promising strategies in improving electromagnetic (EM) wave absorption intensity and broadening absorption bandwidth for metal-organic-frameworks (MOFs) derivatives, but still face challenges in regulating the profitable morphologies. Herein, a self-assembly strategy coupling with a subsequent hydrothermal process have been employed to fabricate hollow Co/N-doped carbon@MnO₂ (H-Co/NC@MnO₂) composites with hierarchical microstructures and abundant hetero-interfaces. The results indicated that H-Co/NC is constructed by the accumulation of abundant MOFs derivatives without interactions, and the amount of KMnO₄ plays an important role in manipulating hierarchical MnO₂ nanosheets and optimizing EM wave absorption. Benefiting from the cooperative merits of hierarchical microstructures, multiple hetero-interfaces and the EM synergy, the maximum reflection loss of H-Co/NC@MnO₂ is as high as −60.2 dB at 3.7 mm and the absorption bandwidth achieves 8.6 GHz with a thickness of 4 mm. This study inspires us a new avenue to regulate the EM wave absorption of MOFs derivatives by hierarchical construction and hetero-interfaces design.