Layer by layer 2D MoS2/rGO hybrids: An optimized microwave absorber for high-efficient microwave absorption

Abstract

Constructing heterostructured microwave absorbers out of low dimensional nanomaterials has been proved an effective method for enhancing the attenuation ability and boarding the effective attenuation bandwidth in electromagnetic wave (EMW) absorbing area. By using a simple intermediate reduction mixing process, 2D layer by layer hierarchical architectures of few-layered MoS2 nanosheets (NMS) and reduced graphene oxide (rGO) are prepared under different volume ratios, which achieve enhanced EMW absorption performance with respect to the pure NMS or rGO. The minimum reflection loss (RL) value of NMS/rGO-5:1 with 20 wt% loading is −55 dB under 2.2 mm compared to −38.42 dB of pure NMS with 60% loading under 2.4 mm or −37.2 dB of pure rGO with 30% loading under 3.5 mm. The effective attenuation bandwidth (EAB, <−10 dB) of NMS/rGO-2:1 with 25% loading is up to ∼6.96 GHz. The enhanced performance of NMS/rGO is attributed to the strong interfacial polarization loss resulting from the NMS/rGO heterojunctions, as well as the defect dipole polarization loss, conduction loss and scattering loss. Furthermore, this work demonstrates the easy fabrication of layer by layer NMS/rGO heterojunctions, paving a way for harvesting unique physicochemical properties of 2D transition metal dichalcogenides/graphene composites. Considering the enhanced EMW absorption performance and greatly reduced filler loading, the resulting 2D layer by layer NMS/rGO show promising prospect in the area of microwave absorption.