▎ 摘　　要

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. (C) 2014 Elsevier B.V. All rights reserved.