Insitu assembly of Fe3O4@FeNi3 spherical mesoporous nanoparticles embedded on 2D reduced graphene oxide (RGO) layers as protective barrier for EMI pollution

Abstract

Electromagnetic interference (EMI) is a major issue due to the increased use of electronic devices operating in the gigahertz frequency range. Consequently, to reduce electromagnetic pollution, materials with considerable magnetic and dielectric loss can be used for the attenuation of electromagnetic waves. In this paper, Fe₃O₄ FeNi₃ spherical mesoporous nanoparticles embedded on reduced graphene oxide (RGO) layers have been synthesized using the hydrothermal reduction method. The specific surface area of Fe₃O₄@FeNi₃/RGO nanocomposite was 67.4 m²/g with a pore size diameter of 3.4 nm (i.e., mesoporous range). Fe₃O₄@FeNi₃/RGO nanocomposites show an enhanced absorption dominant shielding effectiveness (SE) value of 46.49 dB as compared to its binary counterpart Fe₃O₄@FeNi₃, having SE value of 25.21 dB. The synthesized Fe₃O₄@FeNi₃/RGO nanocomposite of thickness 1.42 mm has SE_R of ∼10.32 dB and SE_A of ∼36.15 dB at 15 GHz. Furthermore, it is observed that shielding efficiency increases with increasing reduced graphene oxide (RGO) content in Fe₃O₄@FeNi₃, which is owing to an excellent interconnected network between RGO and Fe₃O₄@FeNi₃. The RGO sheets can create a comprehensive conductive network for the distribution of charges and can enhance dielectric loss because of the layered structure, greater specific surface area and large aspect ratio. Additionally, the mesoporous Fe₃O₄@FeNi₃ hybrid embellished on the surface of RGO may be employed as a multi-pole polarisation centre, enhancing the electronic and space charge polarization of the composites, which is helpful for strong EM wave absorption. It was believed that these nanocomposites would pave the way for the development of RGO-based mesoporous nanocomposites as broadband, lightweight and effective shielding material for practical applications.