Self-Assembled ZnO/Co Hybrid Nanotubes Prepared by Electrospinning for Lightweight and High-Performance Electromagnetic Wave Absorption

In this work, hollow ZnO/Co hybrid nanotubes are prepared by electrospinning followed by calcination and hydrogen reduction process for electromagnetic wave absorption. The texture and electromagnetic wave absorption performance of ZnO/Co hybrid nanotubes with different Co contents are thoroughly investigated. Among the studied hybrid nanotubes, ZnO/Co hybrid nanotubes with the same molar concentrations exhibit superb electromagnetic wave absorbing property. The maximum reflection loss reaches -68.4 dB at 11.4 GHz with a matching thickness of 3.0 mm and the maximum effective absorption (reflection loss <= -10 dB) bandwidth is up to 5.9 GHz (9.5-15.4 GHz) with a matching thickness of 2.6 mm. The superior property could be attributed to the favored impedance matching performance and various loss pathways including natural resonance, interfacial polarizations, dipole polarization, and conductive loss. The unique three-dimensional network structure formed by nanotubes further contributes to the loss performance. The hollow ZnO/Co hybrid nanotubes can be utilized as an ideal candidate for lightweight and high-efficiency electromagnetic wave absorption materials.