One-dimensional MnO@N-doped carbon nanotubes as robust dielectric loss electromagnetic wave absorbers

Dielectric loss materials exhibit appealing ability for electromagnetic wave attenuation due to their tunable permittivity, favorable stability and light weight. Herein, MnO@N-doped carbon nanotubes with adjustable carbon layer are synthesized by thermal decomposition of pyrrole on the surface of MnO2 nanotubes for electromagnetic absorption application. The morphology, composition, internal defects, conductivity and electromagnetic parameters of the composites are fully investigated. By using ANSYS software to simulate the electric field distribution in the material under the excitation of alternating electromagnetic field, the polarization behavior is analyzed in depth. The combination of MnO and carbon endows the composites with enhanced dielectric loss capacity and better impedance matching. The MnO@N-doped carbon composites achieve an optimal absorption intensity of -62.8 dB at 2.4 mm and a broad effective absorption bandwidth of 5.4 GHz with the thickness of 2.5 mm. The facile synthesis method and the superb EMW absorptivity make the tubular core-shell MnO@N-doped carbon composites a promising EMW absorber, and we believe this study will provide new strategies for designing novel dielectric EMW absorbers in the future.