Synthesis of hierarchical core-shell NiFe2O4@MnO2 composite microspheres decorated graphene nanosheet for enhanced microwave absorption performance

doi:10.1016/j.ceramint.2017.05.344

Ceramics International

Volume 43, Issue 14, 1 October 2017, Pages 11367-11375

https://doi.org/10.1016/j.ceramint.2017.05.344 Get rights and content

Abstract

A ternary functional composite NiFe₂O₄@MnO₂@graphene was synthesized successfully via a facile method. The phase constitution, microstructures, morphologies and chemical compositions of the samples were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) and X-ray photoelectron spectroscopy (XPS). It was observed that the NiFe₂O₄ nanoparticles were coated by hierarchically MnO₂ shells and distributed on the surface of graphene. Investigations of EM wave absorption indicated that NiFe₂O₄@MnO₂@ graphene composite has the strongest reflection loss of −47.4 dB at 7.4 GHz at the matching thickness of 3 mm, compared to NiFe₂O₄ and NiFe₂O₄@MnO₂, and its maximum absorption bandwidth (<−10 dB) is 4.3 GHz (from 5.1 to 9.4 GHz). The enhanced microwave absorption performance can be attributed to the hierarchical structure of MnO₂, void space between MnO₂ and graphene, and better impedance matching of ternary composite. The above results indicate that the novel hierarchical NiFe₂O₄@MnO₂@graphene composite, with intense absorption and wide absorption bandwidth, would be a promising absorber with less EM wave interference.

Introduction

With the rapid development of radar detection techniques, electromagnetic (EM) wave absorption materials with strong EM wave absorption and wide-absorbing frequency, have drawn much attention from scientists in the civil and military fields [1], [2], [3]. EM wave absorption materials can convert the EM wave into thermal energy for consumption [4]. According to EM wave absorption principle, the radar absorbers can be divided into dielectric materials, such as graphene [5], [6], [7], conducting polymers [8], [9], [10], and carbon nanotubes [11], [12], and magnetic materials such as Fe₃O₄ [13], [14], [15], NiFe₂O₄ [16] and CoFe₂O₄ [17]. As an outstanding carbon material, graphene is used in various kinds of fields owing to its unique chemical and physical properties [18], [19]. Due to its low density, high permittivity and ease of functionalization, it has been investigated thoroughly as an EM wave absorption material. However, the impedance mismatching of materials with high electrical conductivity may hinder the EM waves from entering into the materials and result in weak absorption and strong reflection [20], which is not beneficial for the attenuation of EM energy. Generally, several types of magnetic materials have been introduced into graphene to decrease the complex permittivity [21]. For instance, Zong et al. synthesized a reduced graphene oxide-CoFe₂O₄ composite and it can reach −44.1 dB at 15.6 GHz, which is ascribed to proper impedance matching and electromagnetic wave attenuation [22]. A minimal reflection loss of −30 dB could be achieved by coupling hollow Fe₃O₄-Fe with graphene composite, at the thickness range of 2–5 nm [23]. Urchinlike Ni/reduced graphene oxide composite displayed the maximum reflection loss of −32.1 dB with an optimal thickness of 2 mm, due to the multi-interfaces, polarization relaxation and synergistic effect [24].

Furthermore, composite microspheres with magnetic core and dielectric shell possess a favorable impedance matching and synergistic effect between permeability and permittivity because of the special core-shell structure [25]. Also, porous composites with hierarchical structure have attracted increasing attention, because the special structure not only enhances the multiple scattering and absorption of EM wave but also decreases the weight of materials. More importantly, the presence of defects from pores and cracks can act as polarized centers and enhance the charge polarizations, bringing about the improvement of EM wave absorption performance [26].

These previous researches inspired this study on developing improved EM absorbers. In this work, a three-dimensional porous composite with NiFe₂O₄ core and MnO₂ shell decorated graphene was synthesized via hydrothermal method. As-prepared NiFe₂O₄@MnO₂ composite possesses higher specific surface area and properer impedance matching compared with NiFe₂O₄ particles. Furthermore, NiFe₂O₄@MnO₂@graphene composite possesses the largest permittivity and can convert EM wave into thermal energy, which is helpful for EM wave absorption performances. Investigations of EM wave absorption properties demonstrate that NiFe₂O₄@MnO₂@graphene composite displays the strongest reflection loss of −47.4 dB at 7.4 GHz with the thickness of 3 mm. The enhanced EM wave absorption mechanism of the NiFe₂O₄@MnO₂@graphene composite was also studied in detail.

Section snippets

Synthesis of NiFe₂O₄@MnO₂@graphene composite

NiFe₂O₄ particles were prepared by a similar procedure as a previous literature [27]. Subsequently, the NiFe₂O₄@MnO₂@graphene composite was synthesized by one-pot hydrothermal method. Briefly, graphene oxide was dissolved in KMnO₄ aqueous solution (1 mg/mL) and the as-obtained NiFe₂O₄ particles (0.3 g) were dispersed in the 0.11 mol/L KMnO₄ (80 mL) solution. The above solution was placed in an ultrasonic bath for 30 min to disperse NiFe₂O₄ particles well. Then, HCl (5 mL) was added drop-wise to the

Results and discussion

The crystal structure of NiFe₂O₄@MnO₂@graphene composite was analyzed by XRD and the results are shown in Fig. 1. The diffraction peaks located at 12.1° and 24.6° can be ascribed to (0 0 1) and (0 0 2) planes of MnO₂ phase (JCPDS No. 80-1098) [25]. Moreover, the peaks at 30.2°, 35.9°, 43.3°, 57.6° and 62.9° correspond to the (2 2 0), (3 1 1), (4 0 0), (5 1 1) and (4 4 0) planes of cubic spinel NiFe₂O₄ (JCPDS No. 10-0325) and no other impurity peaks can be detected [27]. The morphologies and

Conclusion

In summary, a hierarchical 3D NiFe₂O₄@MnO₂@graphene composite was synthesized successfully via a facile method. The NiFe₂O₄ particles were firstly obtained, and then MnO₂ nanosheet arrays grew around the NiFe₂O₄ particles and distributed on the surface of graphene by one-pot hydrothermal method. The introduction of MnO₂ and graphene results in a high attenuation constant and proper impedance matching of the sample. The maximum reflection loss of NiFe₂O₄@MnO₂@graphene composite is −47.4 dB at 7.4

Acknowledgements

The authors acknowledge the financial support from the National Natural Science Foundation of China (Grant No 51303147 and No 51502233), President's Fund of Xi’an Technological University (project No. XAGDXJJ16002) and Natural Science Foundation of Shaanxi Provincial Department of Education (16JK1367).

References (40)

X.B. Li et al.
Enhanced electromagnetic wave absorption performances of Co₃O₄ nanocube/reduced graphene oxide composite
Synth. Met.
(2014)
C.Q. Song et al.
Three-dimensional reduced graphene oxide foam modified with ZnO nanowires for enhanced microwave absorption properties
Carbon
(2017)
K. Nasouri et al.
Designing, modeling and manufacturing of lightweight carbon nanotubes/polymer composite nanofibers for electromagnetic interference shielding application
Compos. Sci. Technol.
(2017)
Y. Zhang et al.
Synthesis, structure and electromagnetic properties of mesoporous Fe₃O₄ aerogels by sol-gel method
Mater. Sci. Eng. B
(2014)
L.L. Zhang et al.
The preparation of Fe₃O₄ cube-like nanoparticles via the ethanol reduction of α-Fe₂O₃ and the study of its electromagnetic wave absorption
Appl. Surf. Sci.
(2015)
H.J. Wu et al.
Peculiar porous α-Fe₂O₃, γ- Fe₂O₃ and Fe₃O₄ nanospheres: facile synthesis and electromagnetic properties
Powder Technol.
(2015)
P.B. Liu et al.
NiFe₂O₄ clusters on the surface of reduced graphene oxide and their excellent microwave absorption properties
Mater. Lett.
(2013)
N. Zhang et al.
Coupling CoFe₂O₄ and SnS nanoparticles with reduced graphene oxide as a high-performance electromagnetic wave absorber
Ceram. Int.
(2016)
P.B. Liu et al.
Cubic NiFe₂O₄ particles on graphene-polyaniline and their enhanced microwave absorption properies
Compos Sci. Technol.
(2015)
M. Zong et al.
Reduced graphene oxide-CoFe₂O₄ composite: synthesis and electromagnetic absorption properties
Appl. Surf. Sci.
(2015)

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Synthesis of hierarchical core-shell NiFe2O4@MnO2 composite microspheres decorated graphene nanosheet for enhanced microwave absorption performance

Abstract

Introduction

Section snippets

Synthesis of NiFe2O4@MnO2@graphene composite

Results and discussion

Conclusion

Acknowledgements

Synth. Met.

Carbon

Compos. Sci. Technol.

Mater. Sci. Eng. B

Appl. Surf. Sci.

Powder Technol.

Mater. Lett.

Ceram. Int.

Compos Sci. Technol.

Appl. Surf. Sci.

Appl. Surf. Sci.

J. Alloy. Compd.

Chem. Eng. J.

Ceram. Int

J. Alloy. Compd.

J. Alloy. Compd.

Compos.: Part A

J. Alloy. Compd.

Chem. Eng. J.

Mater. Lett.

Synthesis of hierarchical core-shell NiFe₂O₄@MnO₂ composite microspheres decorated graphene nanosheet for enhanced microwave absorption performance

Synthesis of NiFe₂O₄@MnO₂@graphene composite