Novel rGO/α-Fe2O3 composite hydrogel: synthesis, characterization and high performance of electromagnetic wave absorption

Abstract

A novel 3D composite hydrogel composed of reduced graphene oxide nanosheets and a-Fe 2 O 3 nanoparticles (rGO/a-Fe 2 O 3 ) was synthesized via a two-step process in a solution phase technique. The experimental results show the composite has an interconnected 3D porous network with micrometer pores, and the a-Fe 2 O 3 nanoparticles with the size of about 50-100 nm are uniformly dispersed onto the thin graphene nanosheets. The rGO/a-Fe 2 O 3 composite hydrogel exhibits excellent microwave absorbability. Compared to a pristine reduced graphene oxide (rGO) hydrogel, the reported composite hydrogel has both wider and stronger wave absorption achieved in the frequency range of 1-18 GHz.The composite with a coating layer thickness of 5.0 mm exhibits a maximum absorption of À33.5 dB at 7.12 GHz and in particular, the product with a coating layer thickness of only 3.0 mm shows a bandwidth of 6.4 GHz (from a frequency of 10.8-17.2 GHz) corresponding to reflection loss at À10 dB.The excellent microwave absorption properties are ascribed to the improved impedance matching. Our findings pave a way to design and prepare lightweight and high performance electromagnetic wave absorption materials based on 3D graphene and other nanomaterials.

In situ preparation of ultralight three-dimensional polypyrrole/nano SiO 2 composite aerogels with enhanced electromagnetic absorption

“…A C C E P T E D ACCEPTED MANUSCRIPT 2 increasing role in the protection of electronic devices as well as human beings from the damage of electromagnetic radiation [1]. To effectively absorb electromagnetic wave, several materials with specific structures have been used for EMA, such as inorganic nanoparticles including Bi 2 S 3 [2], CuS [3,4], α-MnO 2 [5], and ZnO nanorods [6], conducting polymers (CPs) including poly (3,4-…”

Influence of different materials on the microstructure and optical band gap of α-Fe2O3 nanoparticles

“…Enhanced photocatalytic activity has been observed for α-Fe 2 O 3 /graphene oxide composite [7,8]. McDonald et al [9] composite has also been shown to exhibit excellent microwave absorbability, appropriate to use it as a high performance electromagnetic wave absorption material [11]. Xiao et al [12] have synthesized Fe 2 O 3 /graphene composites with different contents of graphene.…”

One Pot Synthesis of Nickel Nanoparticles Stabilized on rGO/Polyethyleneimine Aerogel for the Catalytic Hydrogen Generation

“…The SEM image of NiNPs@rGO-bPEI aerogel (bPEI/ GO = 4) shows a plastic-like form (Fig. 4e, f) [59][60][61]. The TEM images of NiNPs@rGO-bPEI aerogel indicates the successful dispersion of Ni nanoparticles with the size of 18-20 nm on the surface of the rGO-based aerogel (Fig.…”