Design of molybdenum disulfide@polypyrrole compsite decorated with Fe₃O₄ and superior electromagnetic wave absorption performance

Highlights

• A novel MoS₂@polypyrrole@Fe₃O₄ composite was skillfully synthesized.

• There was no any separation procedure during the synthesis process.

• The Fe²⁺ was successively utilized to prepare the Ppy and Fe₃O₄.

• The composite performs excellent EM wave absorbing performance.

Abstract

The MoS₂@polypyrrole@Fe₃O₄ composite was skillfully synthesized via a novel one pot method. No any separation step during the synthesis process, and the Fe²⁺ was successively utilized to prepare the Ppy and Fe₃O₄, which can achieve a high utilization of raw materials. The characterization about microstructure, crystal form, elemental composition and surface functional groups verify the structure of MoS₂@polypyrrole@Fe₃O₄. Its hysteresis loop indicates that the composite performs typical soft magnetism behavior, with a magnetic saturation value of 20.3 emu.g⁻¹, which is helpful to improve the magnetic loss for EM wave absorbing. The reflection loss curve suggested that the composite exhibits superior EM wave absorption performance, with a minimum reflection loss value of –32 dB at the specimen thickness of just 2.0 mm due to the fair electromagnetic matching, interface polarization and interface relaxation. In addition, the one pot method used in this work can promisingly be applied to prepare other similar composites such as carbon fiber@polypyrrole@Fe₃O₄, graphene@polypyrrole@Fe₃O₄.

Introduction

The rapid development of electronic technology in the 21st century has provided many conveniences and changes for human, and the electronic equipment has been widely applied in our daily life, military, aerospace and many other fields [1], [2], [3], [4], [5]. However, the emerged electromagnetic (EM) pollution has also become increasingly serious, which has already been a major impact on current society. Electromagnetic radiation is damaging the human body, causing functional disorders of various organs, inducing the occurrence of various diseases, and even threatening the safety of human life in severe cases. Thus, the research of high performance EM wave absorber has received much attention in recent years [6], [7], [8], [9], [10].

Since the electromagnetic characters of materials involve dielectric loss and magnetic loss, it is quite necessary to make much account of these two aspects on EM wave absorber design. Besides, those single component EM wave absorbers such as Fe₃O₄, ultrafine metal powder, graphite and various carbon materials, great efforts have been made in developing new materials with composite or composite structure which can show the electromagnetic property of optimization due to cooperative affect [11], [12], [13]. For instance, a polyaniline nanoneedles/MoS₂ composite has been reported, and exhibits predominant EM wave absorbing effect with a R_Lmin up to −44.8 dB at 14.5 GHz when the specimen thickness is just 1.6 mm [14]. Many other conductive polymers or MoS₂ such as MoS₂/Fe₃O₄/graphene [15], PANI/C/NiFe₂O₄ [16] and Ppy/PANI [17] were also reported, and they all performed perfect EM wave absorption performances.

In view of material design, simple and accurate preparation method is also an important part [18], [19], [20], [21]. The synthesis process of one pot method is from crude materials directly to target products without any intermediate separation steps, thus having such advantages as simple operation, high raw material utilization rate, environmental friendliness and so on [22], [23], [24]. Through the implementation of one pot method, many functional composite such as graphene@CNTs [25], graphene oxide/PtAg alloy [26], Au@AuPd [27], NFs/rGO [28] etc. have been developed.

In this study, we prepared successfully a novel MoS₂@polypyrrole@Fe₃O₄ composite by using one pot method. The structure and relevant properties of the as-prepared material were characterized and the corresponding absorbing mechanism of the composite for EM wave was discussed.