A three-dimensional absorber hybrid with polar oxygen functional groups of MWNTs/graphene with enhanced microwave absorbing properties

Abstract

Abstract A three-dimensional absorber hybrid with polar oxygen-containing functional groups was fabricated by the incorporation of two-dimensional reduced graphene oxide (rGO) with one-dimensional multi-walled carbon nanotubes (MWNTs) via ultrasonication filtration method. The aim of the work is to investigate the effectiveness of three-dimensional absorber hybrid with polar oxygen-containing functional groups on the enhanced microwave absorbing properties. As a contrast, the three-dimensional absorber hybrid of Graphene nanoplatelets (GNPs) and MWNTs were also fabricated by the same method. The structure and morphology of the GNPs(rGO)/MWNTs hybrids were characterized by scanning electron microscopy (SEM), trans-mission electron microscopy (TEM), X-ray diffraction (XRD) and Raman spectroscopy. SEM and TEM results indicated that the three-dimensional architecture of GNPs(rGO)/MWNTs was fabricated, and the dispersion of GNPs(and/or rGO) was promoted due to the bridge construct of MWNTs between GNPs. The polarization differences between GNPs/MWNTs and rGO/MWNTs were investigated by the Cole-Cole semicircle model. The microwave absorbing results revealed that the rGO/MWNTs hybrids exhibited a −41 dB reflection loss in the frequency at 9.6 GHz with a bandwidth of 0.8 GHz (9.2 GHz–10 GHz) below −20 dB, which was higher than that of the GNPs/MWNTs hybrids (−23 dB at 8.4 GHz, 0.2 GHz bandwidth below −20 dB). This investigation indicated that the three-dimensional with polar oxygen-containing functional groups was beneficial to enhancing microwave absorbing properties.