Fabrication of core–multishell MWCNT/Fe3O4/PANI/Au hybrid nanotubes with high-performance electromagnetic absorption

Abstract

Core–multishell MWCNT/Fe₃O₄/polyaniline (PANI)/Au hybrid nanotubes are synthetized by a facile layer-by-layer technique which well integrates the dielectric components (MWCNT and PANI) and the magnetic absorber (Fe₃O₄) as well as the electromagnetic (EM) wave reflector (Au) into one unit. The hybrid nanotubes are characterized by transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy and vector network analysis. Microstructure analysis indicates that the coverage of the gold nanoparticles could be adjusted simply by varying the weight ratio of the precursors. When gold is introduced into the hybrid nanotubes, the EM absorption is sharply enhanced. The lowest reflection loss value reduces from −22 dB to −60 dB. This may be ascribed to the fact that the introduction of gold nanoparticles is beneficial for the multi-reflection of EM waves within the absorbers, balances the impedance matching between the absorbers and free space, and induces charge redistribution within the hybrid nanotubes generating significant interfacial polarization.