Enhanced microwave absorption properties of N-doped graphene@PANI nanorod arrays hierarchical structures modified by Fe₃O₄ nanoclusters

The hierarchical structures of N-doped graphene (NG)@PANI nanorod arrays modified with Fe₃O₄ nanocluster have been fabricated by a hydrothermal reaction. The as-prepared (NG@PANI@Fe₃O₄) composites were characterized by XRD, Raman and FTIR spectra, VSM, XPS spectroscopy, TEM and FESEM. The results reveal that the surfaces of NG@PANI nanorod arrays are randomly covered by Fe₃O₄ nanocluster with an average size of about 40 nm. With Fe₃O₄ nanoclusters coated on the surfaces of NG@PANI nanorod arrays, the composites exhibit superparamagnetic characteristics at room temperature. Moreover, the microwave absorption properties of both NG@PANI nanorod arrays and NG@PANI@Fe₃O₄ nanocluster were investigated between 2 and 18 GHz microwave frequency bands. The electromagnetic data demonstrates that NG@PANI@Fe₃O₄ nanocluster composites exhibit significantly enhanced microwave absorption properties compared with graphene@Fe₃O₄, which probably originates from improved level of impedance matching and interfacial polarization.