Multiple heteroatom doped carbon nanocages with an open structure enabling superior electromagnetic wave absorption

In comparison with pure carbon materials, the introduction of heteroatoms and the construction of hollow nanostructures can significantly enhance electromagnetic wave absorption properties. Herein, a multiple heteroatom-doped open nanocages with an amorphous structure was successfully designed and prepared. The introduction of heteroatoms, including Zn, Co, and N, results in charge redistribution and the formation of localized polarization centers within the carbon matrix, consequently enhancing dielectric loss. Meanwhile, the synergistic interplay between heteroatoms and defects in the carbon layer further intensifies space charge accumulation and local electric field formation, leading to enhanced dielectric loss. Furthermore, the open-structured nanocage dramatically improves electromagnetic wave penetration depth and energy dissipation efficiency by lowering material density, promoting impedance matching, and providing multiple scattering pathways. Experimental findings indicate that optimized sample achieves a minimum reflection loss of -48.59 dB at a thickness of only 1.82 mm, and an effective absorption bandwidth of 5.92 GHz. This approach thus represents a promising structural design strategy for advancing the performance of lightweight carbon-based microwave absorbing materials.