▎ 摘　　要

A superparamagnetic quaternary nanocomposite of FeCo@SnO2@graphene@PANI was prepared via a three-step method. The obtained quaternary nanocomposite was characterized by XRD, TEM, XPS, FTIR, VSM and VNA analysis. The electromagnetic parameters indicate that FeCo@SnO2@graphene@PANI exhibits enhanced electromagnetic absorption properties compared to FeCo and FeCo@SnO2, which can be mainly attributed to the improved impedance matching. The possible absorption mechanism for the quaternary nanocomposite was also discussed in detail. The maximum reflection loss of FeCo@SnO2@graphene@PANI can reach 39.8 dB at 6.4 GHz and the absorption bandwidth with the reflection loss exceeding -10 dB is 3.1 GHz (from 4.6 to 7.7 GHz) with the thickness of 3 mm. Our results demonstrate that the FeCo@SnO2@graphene@PANI nanocomposite can serve as an excellent microwave absorber. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.