Regulation of impedance matching feature and electronic structure of nitrogen-doped carbon nanotubes for high-performance electromagnetic wave absorption

Abstract

In this study, we developed a facile method to fabricate three-dimensional (3D) structures composed of FeNi alloy nanoparticles encapsulated in N-doped carbon nanotubes that grafted on the SiO2 spheres (FexNiy@[email protected]2) for electromagnetic wave (EMW) absorption. The experimental results suggest that the impedance matching characteristic can be tuned by the introduction of SiO2 spheres in the 3D structure. Density functional theory (DFT) calculations showed that the introduction of Ni improved the polarization and conductive losses of the FexNiy@[email protected]2. As a result, the optimal 3D structure exhibits excellent EMW absorption property with a reflection loss and effective absorption bandwidth are -49.39 dB and 4.32 GHz, respectively, even though the matching thickness is only 1.6 mm, superior to most magnetic carbon-based composites. Thus, our current approach opens up an effective way to the development of low-cost, high-performance EMW absorbers.