reduced graphene oxide prepared by a facile method

reduced graphene oxide prepared by a facile method

Accepted Manuscript Synthesis and electromagnetic wave absorption properties of matrimony vine-like iron oxide/reduced graphene oxide prepared by a fa...

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Accepted Manuscript Synthesis and electromagnetic wave absorption properties of matrimony vine-like iron oxide/reduced graphene oxide prepared by a facile method Hai-rong Chu, Qiang Zeng, Ping Chen, Qi Yu, Dong-wei Xu, Xu-hai Xiong, Qi Wang PII:

S0925-8388(17)31816-9

DOI:

10.1016/j.jallcom.2017.05.199

Reference:

JALCOM 41930

To appear in:

Journal of Alloys and Compounds

Received Date: 24 March 2017 Revised Date:

16 May 2017

Accepted Date: 19 May 2017

Please cite this article as: H.-r. Chu, Q. Zeng, P. Chen, Q. Yu, D.-w. Xu, X.-h. Xiong, Q. Wang, Synthesis and electromagnetic wave absorption properties of matrimony vine-like iron oxide/reduced graphene oxide prepared by a facile method, Journal of Alloys and Compounds (2017), doi: 10.1016/ j.jallcom.2017.05.199. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

ACCEPTED MANUSCRIPT

Synthesis and electromagnetic wave absorption properties of matrimony vine-like Iron oxide/reduced graphene oxide

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prepared by a facile method Hai-rong Chu, a Qiang Zeng, a Ping Chen, *a Qi Yu, *b Dong-wei Xu, a Xu-hai Xiong, b Qi Wang b a.

State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian (116024), China

E-Mail: [email protected] b.

Liaoning Key laboratory of advanced polymer matrix composites, Shenyang Aerospace University,

Shenyang (110136), China

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E-Mail: [email protected]

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Graphical Abstracts:

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Synthesis and electromagnetic wave absorption properties of matrimony vine-like Iron oxide/reduced graphene oxide

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prepared by a facile method Hai-rong Chu, a Qiang Zeng, a Ping Chen, *a Qi Yu, *b Dong-wei Xu, a Xu-hai Xiong, b Qi Wang b

a.

State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian (116024), China

Liaoning Key laboratory of advanced polymer matrix composites, Shenyang Aerospace University,

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b.

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E-Mail: [email protected]

Shenyang (110136), China

E-Mail: [email protected]

Abstract

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Matrimony vine-like α-Fe2O3/reduced graphene oxide have been prepared by a facile method, followed by transformation into Fe3O4/reduced graphene oxide through annealing at 500 ℃ with the particle size and morphology significantly unchanged. By

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changing the mass ratio of iron oxide, the hybrids display optimal electromagnetic

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wave absorption performance. The maximum reflection loss value of α-Fe2O3/reduced graphene oxide is -46.6 dB at 5.6 GHz with a thickness of 4.0 mm and the highest effective absorption bandwidth reaches 4.9 GHz at the thickness of 1.8 mm. Interestingly, after annealing treatment, the hybrids in which α-Fe2O3 were converted into Fe3O4 exhibit an effective absorption bandwidth of 4.6 GHz and the maximum reflection loss value reaches -42.8 dB at 13.3 GHz with the thickness of only 1.8 mm, indicating Fe3O4/reduced graphene oxide can be used as an efficient electromagnetic

ACCEPTED MANUSCRIPT wave absorbing material in high temperature and moisture environment, where Fe3O4 will be oxidized into α-Fe2O3. Results show the enhancement of electromagnetic wave absorption performance originates from synergistic effects of dielectric loss and loss.

Our

study

provides

a

potential

method

for

preparing

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magnetic

environmental resistance electromagnetic wave absorbing materials.

Key words:

Fe3O4, α-Fe2O3, reduced graphene oxide, impedance match,

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electromagnetic wave absorption.

1. Introduction

In recent years, high performance electromagnetic(EM) wave absorbers have received considerable attention due to the rapid development and high demands in

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military fields, such as radar stealth fighter and tanks, and the increasing EM wave radiation caused by the extensive use of electronic devices and wireless communication tools, which are harmful to human health and surrounding

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environment.[1-4] Lots of contributions have been devoted to ferrites and ceramics

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EM wave absorbers.[5, 6] However, narrow effective absorption bandwidth, high density and large matching thickness of these EM wave absorbers hinder their practical applications. Thus, carbon-based materials have become a promising candidate owing to their lightweight, thermal stability and low cost advantages. Till now, many kinds of carbon-based EM wave absorbers have been developed, for example, grape-like Fe3O4/CNT,[7, 8] SiO2/CNTs,[9] Fe/CNTs,[10] carbon nanocoil,[11] Fe3O4/C nanospindles,[12] etc.

ACCEPTED MANUSCRIPT Graphene, a two-dimensional single layer material composed of sp2-bonded carbon atoms as a new star in carbon family once it had been found in 2004, have attracted extensive attention for its excellent thermal, electrical and mechanical

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properties.[13] Recently, researches have revealed that reduced graphene oxide(RGO) owning to its defects and oxide-groups during its preparation process, shows enhanced EM wave absorption performance than carbon nanotubes and graphite.[14,

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15] Nevertheless, imbalanced impedance of RGO leads to absorption with the

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reflection loss (RL) value no more than -10 dB in 1-18 GHz resulting from its non-magnetic characteristic.[15] In order to improve the EM wave absorption properties, combination of RGO with magnetic particles have been researched a lot, such

as

FeCo/RGO,[16]

Fe3O4/RGO,[17-27]

NiFe2O4/RGO,[28,

29]

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CoFe2O4/RGO,[30, 31] Fe2O3/RGO,[32-35] [email protected]€Fe3O4,[36] etc. Among them, Fe3O4 and Fe2O3 has been the most popular due to the facile methods including hydrothermal, ALD-assisted, solvothemal and high-temperature sintering routes for

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preparing them. Nevertheless, these methods are time-consuming, demand high

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temperature or use expensive gas and solvent. Thus, it is an urge to develop a facile, time-saving and scalable method to fabricate lightweight, small thickness, wide effective absorption bandwidth and strong absorption absorber to meet the demands of practical applications. Herein, we synthesize α-Fe2O3/reduced graphene oxide (αF/G) EM wave absorber with excellent absorption property via co-precipitation method. Interestingly, when αF/G are heated to 500℃ and kept for 1h using Ar as protective atmosphere, they can be converted into Fe3O4/ reduced graphene oxide

ACCEPTED MANUSCRIPT (F/G) which retain excellent EM wave absorption performance. This means F/G can be applied in a wide range of circumstances, in regardless of oxidation whether or not. Generally speaking, it paves a scalable way for designing efficient EM wave

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absorbing materials.

2. Experimental section 2.1 Materials

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All chemical reagents were of analytical grade and used without further

Material

Company

(Qingdao,

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purification. Natural graphite flake powder was purchased from Yanhai Carbon China).

Ferric

chloride

(FeCl3),

potassium

permanganate (KMnO4), hydrazine hydrate (N2H4•H2O) and ammonium hydroxide (NH3•H2O) were bought from Sinopharm Chemical Reagent Co., Ltd (Shanghai,

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China).

2.2 Synthesis of graphene oxide solution

Graphite oxide was prepared by Hummers method [37] and turned into graphene

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oxide through ultrasonic processor. Briefly, 2 g natural flaky graphite was added into

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a 500 ml three-neck flask filled with 46 ml concentrated H2SO4 (98%) in an ice bath. Then 6 g KMnO4 was added into the above three-neck flask slowly to keep the temperature of the reaction system below 5 ℃ under mechanical stirring. After being kept in ice bath for 1 h, the system was raised to 35 ℃ and maintained for another 2 h. Successively, 100 ml distilled water was added dropwise and the temperature was maintained at 90 ℃ for 0.5 h under stirring. Finally, the reaction was terminated by 200 ml distilled water and 15 ml H2O2 (30%). The whole precipitate mixture was

ACCEPTED MANUSCRIPT washed with 5% HCl solution and distilled water through centrifugation until the pH of the mixture was 6-7. The resulting gel-like mixture was dispersed in distilled water and sonicated for 1 h under 300 W to obtain graphene oxide solution with the

2.3 Synthesis of α-Fe2O3/reduced graphene oxide (αF/G)

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concentration 5.0 mg/ml.

In a typical process, 3.75 g FeCl3 dissolved in 100 ml distilled water was added

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into the graphene oxide solution (140 ml) contained in a 500 ml flask under

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mechanical stirring, followed by the addition of NH3H2O dropwise to adjust the pH=11 at 50 ℃. Being constantly stirred at 50 ℃ for 0.5 h, the above solution was heated to 95 ℃. After the addition of 10 ml N2H4H2O, the solution was stirred for another 3 h holding at 95 ℃. The black precipitate, denoted as αF/G-1, was washed

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with distilled water and ethanol for several times and dried in vacuum oven at 75 ℃. Keeping other conditions unchanged while the mass of FeCl3 was increased to 5.0 g and 6.25 g, the as-obtained products were named as αF/G-2 and αF/G-3.

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2.4 Synthesis of Fe3O4/reduced graphene oxide (F/G)

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The sample αF/G-1 was placed in a furnace and heated to 500 ℃ at a heating rate of 10 ℃/min under the protection of Ar. After being held at 500 ℃ for 1 h, the reaction system was cooled to room temperature and the resulted black solid (F/G-1) was collected. αF/G-2 and αF/G-3 were treated with the same process. The final product were denoted as F/G-2 and F/G-3, respectively. The whole process are illustrated in Fig. 1. 2.5 Characterization

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crystalline

structures

were

characterized

by

D/Max-2400

X-ray

diffractometer with Cu Kα radiation. Raman spectra were recorded on Thermal Scientific DXR spectrometer with 532 nm laser. X-ray photoelectron spectra (XPS)

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were performed on Thermo ESCALAB 250 with Al Kα radiation. The morphology and microstructure of the samples were characterized by field-emission scanning electron microscopy (FESEM, SU8010), transmission electron microscopy (TEM,

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JEOL JEM-2010), and high-resolution transmission electron microscopy (HRTEM,

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JEOL JEM-2010). TG analysis of the products were performed on a NETZSCH TG 209 thermogravimetric analyzer under air atmosphere at a heating rate of 10 ℃/min from 40 to 700 ℃.

2.6 Measurements of EM absorption properties

measured

with

an

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In order to reveal the EM wave absorbing mechanism, the ε', ε″, µ', µ″ were AV3629D

vector

network

analyzer

by

using

the

transmission/reflection coaxial line method in the frequency range of 1-18 GHz. All

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samples used for measurement were prepared by mixing αF/G or F/G with paraffin at

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a weight ratio of 1:1. Then, the mixtures were pressed into toroidal shape compacts (φouter=7.00 mm

φinner=3.04 mm).

3. Results and discussion The crystalline structure and phase purity were characterized by XRD. As shown

in Fig. S1 (Supporting information), the sharp diffraction peak at 26.5° can be indexed to (002) crystal plane of original graphite. After oxidation, a broad diffraction peak appears at 11.5°while the sharp diffraction of graphite disappears, meaning the

ACCEPTED MANUSCRIPT increase of interlayer distance of graphite due to the oxygen functional groups introduced to its surface. Fig. 2a shows the XRD patterns of αF/G with different content of α-Fe2O3, all the diffraction peaks can be indexed to α-Fe2O3 (JCPDS

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89-0598) and no other diffraction peaks of iron oxide can be found. Besides, αF/G-1 shows a weak broad diffraction peak at 26.5°which can be attributed to the disorder in the RGO layers. However, when the content of FeCl3 increases, more α-Fe2O3

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particles formed and hindered the stack of RGO layer, leading to the disappearance of

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the broad diffraction peak. Fig. 2b presents the XRD patterns of F/G originated from annealing treatment of αF/G at 500 ℃ for 1 h using Ar as protective atmosphere. All the diffraction peaks can be attributed to magnetite Fe3O4 (JCPDS 99-0073), indicating the transformation from α-Fe2O3 to Fe3O4.

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The morphology and microstructure of αF/G and F/G were characterized by SEM and TEM. Fig. 3 shows the SEM images of αF/G and F/G powders. It could be observed from Fig. 3a the matrimony vine-like Fe3O4 particles about 200nm in length

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and 90nm in diameter by average are encapsulated by RGO due to the low content of

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Fe3O4. With the increasing addition mass of FeCl3, more matrimony vine-like Fe3O4 particles formed and covered on both sides of RGO, as shown in Fig. 3b. Moreover, matrimony vine-like Fe3O4 particles aggregated to each other due to the magnetic force. It is obvious that RGO is almost covered by Fe3O4 particles and could not be seen clearly when the mass of FeCl3 was increased to 6.25 g, as shown in Fig. 3c. Fig. 3d displays the image of αF/G-3. In order to confirm the ratio of Fe3O4 particles, TG characterization was performed, as presented in Fig. S2 (Supporting information). The

ACCEPTED MANUSCRIPT weight loss below 150 ℃ originates from absorbed water and the loss from 200 to 550 ℃ can be ascribed to pyrolysis of RGO. For F/G-1, F/G-2 and F/G-3, the ratio of Fe3O4 particles are 50.1%, 75.6% and 81.9%, respectively. A weight gain from 239 to

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300 ℃ may result from the oxidation of Fe3O4. Fig. 4 displays the TEM and HRTEM images of αF/G-2 and F/G-2. Comparing Fig. 4a and 4b, it can be found that the size and morphology of the iron oxide have not changed significantly after annealing

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treatment. A crystalline lattice spacing of 0.27nm corresponding to the (104) plane of

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α-Fe2O3 can be seen from the HRTEM image of αF/G-2, while the spacing of 0.48nm related to the (111) plane of the Fe3O4 has been detected for F/G-2. Fig. 5a presents the Raman spectral of graphite, GO, αF/G-3 and F/G-3. The characteristic peaks at 1350 cm-1 and 1590 cm-1 which are known as D and G bands

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could be detected for all samples. It is well known that D band corresponds to structural defects and edges associated with sp3-carbon atoms and G band is associated with E2g mode originated from sp2-carbon atoms, respectively.[38]

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Furthermore, for αF/G-3, the peaks at 220 cm-1 and 229 cm-1 are the characteristic

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peaks of α-Fe2O3 while the peaks at 680 cm-1 for F/G-3 are the characteristic peak of Fe3O4.[39] In order to further illustrate the change of α-Fe2O3 to Fe3O4, XPS characterization was used and shown in Fig. 5b. The Fe 2p XPS spectrum exhibits two peaks for F/G-2 at 711.1 eV and 724.7 eV associated with Fe 2p3/2 and Fe 2p1/2 of Fe3O4, respectively, while for αF/G-2 they are at 710.4 eV and 723.8 eV corresponding to α-Fe2O3. In addition, a characteristic satellite peak at 719.2 eV of α-Fe2O3 has been detected for αF/G-2. [12, 23] The results of Raman and XPS are

ACCEPTED MANUSCRIPT well in agreement with XRD patterns. The EM wave absorption properties of F/G and αF/G were investigated in the frequency range of 1-18 GHz by mixing F/G and αF/G with paraffin. Based on the

following equations. [12, 16]

µr  2πfd  tanh  j ( ) µrεr  εr c   Zin − Z 0 Zin + Z 0

(2)

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RL = 20 log

(1)

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Zin = Z 0

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transmit line theory, reflection loss (RL) of the material can be calculated by the

where Zin is the input impedance of the materials, Z0 is the impedance of free space, f is the frequency of EM wave, d is the thickness of the material, c is the velocity of light in vacuum, εr and µr are relative complex permittivity (εr=ε'-jε″) and relative

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complex permeability (µr=µ'-jµ″) of the material. It is recognized that a material with the RL value under -10 dB, indicating 90% absorption of electromagnetic wave energy, [16] can be used as effective EM wave absorber.

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Since different effective absorption band can be achieved by adjusting the

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thickness of the material, RL values of αF/G-paraffin composites versus frequency from 1-18 GHz at different thickness are plotted and shown in Fig. 6a-c. It can be concluded αF/G-2 exhibits the most excellent absorption performance due to the impedance match and high loss. The parts circled by red line denote the RL values below -10 dB. In order to show the details of excellent EM wave absorption performance of

αF/G-2, the RL values of αF/G-2 from 1.5 to 8.0 mm have been plotted in Fig. 7.

ACCEPTED MANUSCRIPT When the thickness is 1.8 mm, αF/G-2 presents the highest effective absorption bandwidth of 4.9 GHz covering from 12.0 to 16.9 GHz. The maximum RL value reaches -46.6 dB at 5.6 GHz with a thickness of 4.0 mm. Moreover, the absorption

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bandwidth with RL values below -20 dB is observed in 2.4-18 GHz with the thickness ranging from 1.5 to 8.0 mm.

After annealing at 500 ℃ for 1 h, α-Fe2O3 were transformed to Fe3O4 with the

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morphology and size significantly unchanged and F/G still exhibit excellent EM

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absorption properties. Fig. 8 a-c shows the RL values of F/G with different ratio of Fe3O4 versus frequency at different thickness. Similar to αF/G, F/G-2 also possesses stronger EM absorption properties than the other two samples. By comparing Fig. 6 a-c with Fig. 8 a-c, some changes of the EM absorption performance between F/G and

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αF/G have been found, including the effective bandwidth and maximum RL values. It is recognized that the morphology, particle size, crystal structure, loading ratio and thickness of the materials are crucial factors to their EM absorption performance.

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However, in our study, the morphology and the particle size of α-Fe2O3 show little

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changes compared with that of Fe3O4. Thus, under the same loading ratio and thickness, the crystal structure of the particles decorated on reduced graphene oxide accounts for the main reason of the difference of EM absorption performance between F/G and αF/G. Compared with Fe3O4 possessing an inverse-spinel structure, α-Fe2O3 possess a corundum crystal structure and show weak magnetic properties due to the lack of Fe2+ and the atom arrangement, [40] leading to the difference of permeability and permittivity between F/G and αF/G. According to equation (1) and (2), different

ACCEPTED MANUSCRIPT EM absorption performance can be obtained. Fig. 9 displays the RL values of F/G-2 with the thickness ranging from 1.5 to 8.0 mm. When the thickness is 1.8 mm, F/G-2 exhibits the highest effective bandwidth of

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4.6 GHz and the maximum RL value of -42.8 dB at 13.6 GHz. The results show that F/G-2 can be a promising absorber for practical application and used in different wavebands. Furthermore, F/G-2 could retain excellent absorption performance even

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under hot-wet environment where Fe3O4 will be transformed to α-Fe2O3. For

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comparison, the EM wave absorption properties of F/G and αF/G together with similar material system are displayed in Table 1.

Actually, excellent EM absorption properties result from good impedance match and EM energy loss inside the material, which are associated with dielectric loss and

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magnetic loss determined mainly by its relative complex permittivity (εr=ε'-jε″) and relative complex permeability (µr=µ'-jµ″). In order to reveal the absorbing mechanisms of the as-obtained materials, εr and µr will be discussed in detail in the

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following part. Herein, εr and µr of αF/G and F/G have much in common, so we only

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discuss εr and µr of F/G while εr and µr of αF/G are presented in Fig. S3 (Supporting information).

The real part of relative complex permittivity ε' represents the storage of EM

wave energy, while the imaginary part ε″ means the loss of EM wave energy. It can be observed from Fig. 10a that ε' decrease with increasing frequency, apart from two resonance peaks at 10.7 GHz and 14.6 GHz, changing from 21.7 to 9.0, 18.3 to 8.2 and 15.9 to 7.5 for F/G-1, F/G-2 and F/G-3, respectively. Besides, ε' also decrease

ACCEPTED MANUSCRIPT with the increasing content of Fe3O4 and the reason may be that the conducting networks decrease due to less content of RGO, leading to lower conductivity. In the frequency range of 1-8 GHz, ε″ (Fig. 10b) decrease with increasing frequency, but

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became to fluctuate and exhibit multiple peaks in 8-18 GHz due to resonance behaviors.[47, 48] It is well recognized that dielectric polarization include dipolar polarization, interfacial polarization which is also known as space charge polarization

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or Maxwell-Wagner polarization,[49] electron polarization and ion polarization.

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However, in GHz frequency range these resonance peaks are due to dipolar polarization and interfacial polarization, because electron polarization and ion polarization often occur in the frequency range of THz and PHz.[50] Thus, dielectric loss originates from dipolar polarization relaxation, interfacial polarization relaxation

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and conductivity loss. Firstly, interfacial polarization often takes place between the interfaces consisting of two or more components with different conductivity. Given to the structure of F/G, many charges would gather around the interfaces not only

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between Fe3O4 particles and RGO but Fe3O4 themselves, thus resulting in enhanced

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interfacial polarization relaxation which is beneficial to EM wave absorption. Secondly, the defects and residual bonds in RGO acting as polarization centers contribute to dipolar polarization relaxation. Thirdly, conductivity loss originating from the conductivity of RGO plays an important role in dielectric loss. [7] Fig. 10c and d show the frequency dependence of real (µ') and imaginary (µ″) part of relative complex permeability. In Fig. 10c, µ' show a sharp decline in 1-6.9 GHz and remain approximately constant in 6.9-12.0 GHz, but exhibit multi peaks in

ACCEPTED MANUSCRIPT 12.0-18 GHz. However, µ″ show a resonance peak in 1-6.0 GHz and became to decrease during 6.0-10.2 GHz. In the range from 11.0 to 12.8 GHz, µ″ displays a sharp decline and become negative. The negative valued of µ″ denote F/G-paraffin

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radiate out magnetic energy, which may result from ac electric field caused by the motion of charges. [51, 52] In 12.8-18 GHz range, µ″ display multi peaks. In gigahertz frequency range, eddy current loss, exchange resonance and natural

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resonance are the dominating factors for magnetic loss. [2] According to the equation

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µ″≈2πµ0(µ′)2σd2f/3, µ″(µ′)-2f -1would remain constant if magnetic loss only resulted from eddy current loss. However, it can be observed from Fig.11 that the value of

µ″(µ′)-2f

-1

varies in the 1-18 GHz frequency range, which means eddy current loss

may be suppressed. On the other hand, the peaks of µ″ in 1-6 GHz are probably

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induced by natural resonance which are agreed with other references and can be calculated by the Kittel equation. [53, 54]

(3)

Ha = 4 K 1 3µ 0 Ms

(4)

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2πfr = γHa

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Where γ is the gyromagnetic ratio, Ha is the anisotropy field, K1 is the anisotropy coefficient and Ms is the saturation magnetization. The peak of µ″ around 17GHz are due to the exchange resonance according to Aharoni theory. [55] In order to comprehend the EM absorption mechanisms of F/G, dielectric and magnetic loss are summarized in Fig. 12. Dielectric tangent loss (tanδe=ε″/ε′) and magnetic tangent loss (tanδu=µ″/µ′) can be used to evaluate dielectric loss and magnetic loss. The higher dielectric and

ACCEPTED MANUSCRIPT magnetic loss, the more EM wave energy can be absorbed by the material. It can be concluded from Fig. 13 that tanδe are higher than tanδu in the whole range which means dielectric loss accounts for the main factor in EM wave absorption. Tanδe of

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F/G-2 is lower than that of F/G-1, but higher than that of F/G-3. However, F/G-2 exhibits the most excellent EM wave absorption performance. The reason is that the EM parameters of F/G-2 meet the impedance matching character, leading to more

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incidence of EM wave into the materials instead of reflection. Moreover, the balanced

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dielectric loss and magnetic loss enhance the EM absorption properties. Thus the EM absorption properties of F/G-2 is better than the other two’s.

4. Conclusion

In summary, we have successfully fabricated matrimony vine-like αF/G hybrids

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through co-precipitation method. After annealing at 500 ℃ under Ar atmosphere for 1 h, α-Fe2O3 can be converted to Fe3O4 with the particle size and morphology significantly unchanged. By tuning the mass ratio of iron oxide, the optimal EM

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parameters of the iron oxide/reduced graphene oxide can be obtained and both the

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αF/G-2 and F/G-2 show excellent EM wave absorption performance. The maximum RL value of -46.6 dB and the highest effective absorption bandwidth of 4.9 GHz for

αF/G-2 was achieved with the thickness of 4.0 mm and 1.8 mm, respectively. Besides, the effective bandwidth of αF/G-2 below -20 dB can cover 2.4-18 GHz with the thickness ranging from 1.5 to 8.0 mm. As for F/G-2, the maximum RL value of -42.8 dB and the highest effective absorption bandwidth of 4.6 GHz can be obtained at the thickness of 1.8 mm. The enhanced EM wave absorption properties originate from the

ACCEPTED MANUSCRIPT synergistic effects of dielectric loss and magnetic loss. Furthermore, F/G-2 can retain excellent EM wave absorption properties even under high temperature and oxidation in which circumstance Fe3O4 will be oxidized to α-Fe2O3. In a word, αF/G-2 and

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F/G-2 can be promising EM wave absorbers considering the facile, time-saving and scalable method for preparing them.

Acknowledgements

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This work was supported by the National Defense key program Fundamental

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Research program [No.A352011xxxx], National Natural Science Foundation of China (No.51303106), Natural Science Foundation of Liaoning [No.201602149], Liaoning Excellent Talents in University [No.LJQ2015085], Liaoning Key Laboratory Fundamental Research Project [No.LZ2015057] and Key Laboratory of Materials

[No.LABKF1502].

References:

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Modification by Laser, Ion and Electron Beams of Ministry of Education

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[1] F. Shahzad, M. Alhabeb, C.B. Hatter, B. Anasori, S.M. Hong, C.M. Koo, Y. Gogotsi, Electromagnetic interference shielding with 2D transition metal carbides (MXenes), Science, 353 (2016) 1137-1140.

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[2] A.P. Singh, M. Mishra, D.P. Hashim, T. Narayanan, M.G. Hahm, P. Kumar, J. Dwivedi, G. Kedawat, A. Gupta, B.P. Singh, Probing the engineered sandwich network of vertically aligned carbon nanotube–reduced graphene oxide composites for high performance electromagnetic interference shielding applications, Carbon, 85 (2015) 79-88. [3] B. Wen, M. Cao, M. Lu, W. Cao, H. Shi, J. Liu, X. Wang, H. Jin, X. Fang, W. Wang, Reduced graphene oxides: light℃weight and high℃efficiency electromagnetic interference shielding at elevated temperatures, Advanced Materials, 26 (2014) 3484-3489. [4] B. Wen, X. Wang, W. Cao, H. Shi, M. Lu, G. Wang, H. Jin, W. Wang, J. Yuan, M. Cao, Reduced graphene oxides: the thinnest and most lightweight materials with highly efficient microwave attenuation performances of the carbon world, Nanoscale, 6 (2014) 5754-5761. [5] L. Kong, Z. Li, L. Liu, R. Huang, M. Abshinova, Z. Yang, C. Tang, P. Tan, C. Deng, S. Matitsine, Recent progress in some composite materials and structures for specific electromagnetic applications, International materials reviews, 58 (2013) 203-259.

ACCEPTED MANUSCRIPT [6] X. Yin, L. Kong, L. Zhang, L. Cheng, N. Travitzky, P. Greil, Electromagnetic properties of Si–C–N based ceramics and composites, International Materials Reviews, 59 (2014) 326-355. [7] Y. H. Chen, Z. H. Huang, M. M. Lu, W. Q. Cao, J. Yuan, D. Q. Zhang, M. S. Cao, 3D Fe3O4 nanocrystals decorating carbon nanotubes to tune electromagnetic properties and enhance microwave absorption capacity, Journal of Materials Chemistry A, 3 (2015) 12621-12625. [8] M. M. Lu, M. S. Cao, Y. H. Chen, W. Q. Cao, J. Liu, H. L. Shi, D. Q. Zhang, W. Z. Wang, J. Yuan, Multiscale assembly of grape-like ferroferric oxide and carbon nanotubes: a smart absorber prototype

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varying temperature to tune intensities, ACS applied materials & interfaces, 7 (2015) 19408-19415.

[9] M. Chen, Y. Zhu, Y. Pan, H. Kou, H. Xu, J. Guo, Gradient multilayer structural design of CNTs/SiO2 composites for improving microwave absorbing properties, Materials & Design, 32 (2011) 3013-3016.

[10] R. Che, L.M. Peng, X.F. Duan, Q. Chen, X. Liang, Microwave absorption enhancement and

SC

complex permittivity and permeability of Fe encapsulated within carbon nanotubes, Advanced Materials, 16 (2004) 401-405.

[11] D. L. Zhao, Z. M. Shen, Preparation and microwave absorption properties of carbon nanocoils, Materials Letters, 62 (2008) 3704-3706.

M AN U

[12] X. Liu, X. Cui, Y. Chen, X. J. Zhang, R. Yu, G. S. Wang, H. Ma, Modulation of electromagnetic wave absorption by carbon shell thickness in carbon encapsulated magnetite nanospindles–poly (vinylidene fluoride) composites, Carbon, 95 (2015) 870-878.

[13] K.S. Novoselov, A.K. Geim, S.V. Morozov, D. Jiang, Y. Zhang, S.V. Dubonos, I.V. Grigorieva, A.A. Firsov, Electric field effect in atomically thin carbon films, science, 306 (2004) 666-669. [14] M. S. Cao, X. X. Wang, W. Q. Cao, J. Yuan, Ultrathin graphene: electrical properties and highly efficient electromagnetic interference shielding, Journal of Materials Chemistry C, 3 (2015) 6589-6599.

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[15] C. Wang, X. Han, P. Xu, X. Zhang, Y. Du, S. Hu, J. Wang, X. Wang, The electromagnetic property of chemically reduced graphene oxide and its application as microwave absorbing material, Applied Physics Letters, 98 (2011) 072906.

[16] X. Li, J. Feng, Y. Du, J. Bai, H. Fan, H. Zhang, Y. Peng, F. Li, One-pot synthesis of CoFe2O4/graphene oxide hybrids and their conversion into FeCo/graphene hybrids for lightweight and

EP

highly efficient microwave absorber, Journal of Materials Chemistry A, 3 (2015) 5535-5546. [17] P. Guan, X. Zhang, J. Guo, Assembled Fe3O4 nanoparticles on graphene for enhanced electromagnetic wave losses, Applied Physics Letters, 101 (2012) 153108.

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[18] C. Hu, Z. Mou, G. Lu, N. Chen, Z. Dong, M. Hu, L. Qu, 3D graphene–Fe3O4 nanocomposites with high-performance microwave absorption, Physical Chemistry Chemical Physics, 15 (2013) 13038-13043.

[19] X. Li, H. Yi, J. Zhang, J. Feng, F. Li, D. Xue, H. Zhang, Y. Peng, N.J. Mellors, Fe3O4–graphene hybrids: nanoscale characterization and their enhanced electromagnetic wave absorption in gigahertz range, Journal of nanoparticle research, 15 (2013) 1472. [20]

B.

Shen,

W.

Zhai,

M.

Tao,

J.

Ling,

W.

Zheng,

Lightweight,

multifunctional

polyetherimide/[email protected] Fe3O4 composite foams for shielding of electromagnetic pollution, ACS applied materials & interfaces, 5 (2013) 11383-11391. [21] K. Singh, A. Ohlan, V.H. Pham, R. Balasubramaniyan, S. Varshney, J. Jang, S.H. Hur, W.M. Choi, M. Kumar, S. Dhawan, Nanostructured graphene/Fe3O4 incorporated polyaniline as a high performance shield against electromagnetic pollution, Nanoscale, 5 (2013) 2411-2420. [22] X. Sun, J. He, G. Li, J. Tang, T. Wang, Y. Guo, H. Xue, Laminated magnetic graphene with

ACCEPTED MANUSCRIPT enhanced electromagnetic wave absorption properties, Journal of Materials Chemistry C, 1 (2013) 765-777. [23] G. Wang, Z. Gao, G. Wan, S. Lin, P. Yang, Y. Qin, High densities of magnetic nanoparticles supported on graphene fabricated by atomic layer deposition and their use as efficient synergistic microwave absorbers, Nano Research, 7 (2014) 704-716. [24] H. L. Xu, H. Bi, R. B. Yang, Enhanced microwave absorption property of bowl-like Fe3O4 hollow spheres/reduced graphene oxide composites, Journal of Applied Physics, 111 (2012) 07A522.

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[25] J. Zheng, H. Lv, X. Lin, G. Ji, X. Li, Y. Du, Enhanced microwave electromagnetic properties of Fe3O4/graphene nanosheet composites, Journal of Alloys and Compounds, 589 (2014) 174-181.

[26] T. Wang, Z. Liu, M. Lu, B. Wen, Q. Ouyang, Y. Chen, C. Zhu, P. Gao, C. Li, M. Cao, Graphene–Fe3O4 nanohybrids: synthesis and excellent electromagnetic absorption properties, Journal of Applied Physics, 113 (2013) 024314.

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[27] L. Wang, J. Zhu, H. Yang, F. Wang, Y. Qin, T. Zhao, P. Zhang, Fabrication of hierarchical [email protected]@[email protected] quaternary composite and its improved electrochemical performance, Journal of Alloys and Compounds, 634 (2015) 232-238.

[28] M. Fu, Q. Jiao, Y. Zhao, Preparation of NiFe2O4 nanorod–graphene composites via an ionic liquid

M AN U

assisted one-step hydrothermal approach and their microwave absorbing properties, Journal of Materials Chemistry A, 1 (2013) 5577-5586.

[29] J. Z. He, X. X. Wang, Y. L. Zhang, M. S. Cao, Small magnetic nanoparticles decorating reduced graphene oxides to tune the electromagnetic attenuation capacity, Journal of Materials Chemistry C, 4 (2016) 7130-7140.

[30] X. Li, J. Feng, H. Zhu, C. Qu, J. Bai, X. Zheng, Sandwich-like graphene nanosheets decorated with superparamagnetic CoFe2O4 nanocrystals and their application as an enhanced electromagnetic

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wave absorber, RSC Advances, 4 (2014) 33619-33625.

[31] F. Ren, G. Zhu, P. Ren, K. Wang, X. Cui, X. Yan, Cyanate ester resin filled with graphene nanosheets and CoFe2O4-reduced graphene oxide nanohybrids as a microwave absorber, Applied Surface Science, 351 (2015) 40-47.

[32] L. Kong, X. Yin, Y. Zhang, X. Yuan, Q. Li, F. Ye, L. Cheng, L. Zhang, Electromagnetic wave

EP

absorption properties of reduced graphene oxide modified by maghemite colloidal nanoparticle clusters, The Journal of Physical Chemistry C, 117 (2013) 19701-19711. [33] Y. Ren, C. Zhu, L. Qi, H. Gao, Y. Chen, Growth of γ-Fe2O3 nanosheet arrays on graphene for

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electromagnetic absorption applications, RSC Advances, 4 (2014) 21510-21516. [34] A.P. Singh, M. Mishra, P. Sambyal, B.K. Gupta, B.P. Singh, A. Chandra, S. Dhawan, Encapsulation of γ-Fe2O3 decorated reduced graphene oxide in polyaniline core–shell tubes as an exceptional tracker for electromagnetic environmental pollution, Journal of Materials Chemistry A, 2 (2014) 3581-3593.

[35] H. Zhang, A. Xie, C. Wang, H. Wang, Y. Shen, X. Tian, Novel rGO/α-Fe2O3 composite hydrogel: synthesis, characterization and high performance of electromagnetic wave absorption, Journal of Materials Chemistry A, 1 (2013) 8547-8552. [36] Q. Zeng, X. H. Xiong, P. Chen, Q. Yu, Q. Wang, R. C. Wang, H. R. Chu, [email protected]€Fe3O4 microspheres with spongy shells: self-assembly and microwave absorption performance, Journal of Materials Chemistry C, 4 (2016) 10518-10528. [37] W.S. Hummers Jr, R.E. Offeman, Preparation of graphitic oxide, Journal of the American Chemical Society, 80 (1958) 1339-1339.

ACCEPTED MANUSCRIPT [38] V. Chandra, J. Park, Y. Chun, J.W. Lee, I.-C. Hwang, K.S. Kim, Water-dispersible magnetite-reduced graphene oxide composites for arsenic removal, ACS nano, 4 (2010) 3979-3986. [39] D. De Faria, S. Venâncio Silva, M. De Oliveira, Raman microspectroscopy of some iron oxides and oxyhydroxides, Journal of Raman spectroscopy, 28 (1997) 873-878.

M AN U

SC

RI PT

[40] G. B. Sun, B. X. Dong, M. H. Cao, B. Q. Wei, C. G. Hu, Hierarchical Dendrite-Like Magnetic Materials of Fe3O4, γ-Fe2O3, and Fe with High Performance of Microwave Absorption, Chemistry of Materials, 23(2011) 1587-1593. [41] H. B. Yang, T. Y, Y. Lin, J. F. Zhu, F. Wang, Microwave absorbing properties of the ferrite composites based on graphene, Journal of Alloys and Compounds, 683 (2016) 567e574. [42] H. B. Yang, T. Ye, Y. Lin, M. Liu, Preparation and microwave absorption property of graphene/BaFe12O19/CoFe2O4 nanocomposite, Applied Surface Science, 357 (2015) 1289–1293. [43] X. Huang, X. Yan, L. Xia, P. Wang, Q. Wang, X. Zhang, B. Zhong, H. Zhao, G. Wen, A three-dimensional graphene/Fe3O4/carbonmicrotube of sandwich-type architecture with improved wave absorbing performance, Scripta Materialia, 120 (2016) 107–111. [44] Y. Wang, Y. Huang, Q. F. Wang, Q. He, M. Zong, Preparation of graphene/BaFe12O19–Ni0.8Zn0.2Fe2O4 nanocomposite and its microwave absorbing properties, Journal of Sol-Gel Science and Technology, 67 (2013) 344–350. [45] R. Zhang, X. X. Huang, B. Zhong, L. Xia, G. W. Wen and Y. Zhou, Enhanced microwave absorption properties of ferroferric oxide/graphene composites with a controllable microstructure, RSC Advances, 6 (2016) 16952–16962. [46] S. L. Zhang, Q.Z. Jiao, J. Hua, J. J. Li, Y. Zhao, H.S. Li, Q. Wu, Vapor diffusion synthesis of rugby-shaped CoFe2O4/graphene composites as absorbing materials, Journal of Alloys and Compounds, 630 (2015) 195–201.

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[47] W. Liu, H. Li, Q. Zeng, H. Duan, Y. Guo, X. Liu, C. Sun, H. Liu, Fabrication of ultralight three-dimensional graphene networks with strong electromagnetic wave absorption properties, Journal of Materials Chemistry A, 3 (2015) 3739-3747.

[48] L. Zhang, X. Yu, H. Hu, Y. Li, M. Wu, Z. Wang, G. Li, Z. Sun, C. Chen, Facile synthesis of iron oxides/reduced graphene oxide composites: application for electromagnetic wave absorption at high

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temperature, Scientific reports, 5 (2015) 9298.

[49] B.D. Bertram, R.A. Gerhardt, Effects of Frequency, Percolation, and Axisymmetric Microstructure on the Electrical Response of Hot‐ Pressed Alumina–Silicon Carbide Whisker Composites, Journal of

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the American Ceramic Society, 94 (2011) 1125-1132. [50] Y. Chen, P. Gao, C. Zhu, R. Wang, L. Wang, M. Cao, X. Fang, Synthesis, magnetic and electromagnetic wave absorption properties of porous Fe3O4/Fe/SiO2 core/shell nanorods, Journal of Applied Physics, 106 (2009) 054303. [51] L. Deng, M. Han, Microwave absorbing performances of multiwalled carbon nanotube composites with negative permeability, Applied physics letters, 91 (2007) 023119. [52] X. L. Shi, M. S. Cao, J. Yuan, X. Y. Fang, Dual nonlinear dielectric resonance and nesting microwave absorption peaks of hollow cobalt nanochains composites with negative permeability, Applied Physics Letters, 95 (2009) 163108. [53] C. Kittel, On the theory of ferromagnetic resonance absorption, Physical Review, 73 (1948) 155. [54] Y. Zhan, F. Meng, Y. Lei, R. Zhao, J. Zhong, X. Liu, One-pot solvothermal synthesis of sandwich-like graphene nanosheets/Fe3O4 hybrid material and its microwave electromagnetic properties, Materials Letters, 65 (2011) 1737-1740.

ACCEPTED MANUSCRIPT [55] A. Aharoni, Exchange resonance modes in a ferromagnetic sphere, Journal of applied physics, 69

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Figure Captions: Fig. 1 Schematic illustration of αF/G and F/G formation process. Fig. 2 (a) XRD patterns of the prepared products αF/G-1(1), αF/G-2(2) and αF/G-3(3),

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(b) the products of F/G-1(1), F/G-2(2) and F/G-3(3). Fig. 3 SEM images of (a) F/G-1, (b) F/G-2, (c) F/G-3 and (d) αF/G-3. Fig. 4 TEM and HRTEM images of (a) and (c) αF/G-2, (b) and (d) F/G-2 Fig. 5 (a) Raman spectra of graphite(1), GO(2), F/G-3(3) and αF/G-3(4), (b) Fe 2p XPS spectrum of F/G-2 and αF/G-2

Fig. 6 RL values and 3D representation for αF/G-paraffin composites: (a) αF/G-1, (b)

αF/G-2 and (c) αF/G-3 at the thickness ranging from 1.0 to 5.0 mm.

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Fig. 7 (a) RL values of αF/G-2 composites at different thickness ranging from 1.5 to 8.0 mm, (b) the sample achieves an effective absorption bandwidth of 4.9 GHz at the

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thickness of 1.8 mm and reaches the maximum RL value of -46.6 dB (5.6 GHz) at the thickness of 4.0 mm

Fig. 8 RL values and 3D representation for F/G-paraffin composites: (a)F/G-1, (b)F/G-2 and (c)F/G-3 at the thickness ranging from 1.0 to 5.0 mm. Fig. 9 (a) RL values of F/G-2 composites at different thickness ranging from 1.5 to 8.0 mm, (b) the sample achieves an effective absorption bandwidth of 4.6 GHz and

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reaches the maximum RL value of -42.8 dB (13.6 GHz) at the thickness of 1.8 mm. Fig. 10 Real (a) and imaginary (b) part of permittivity of F/G-paraffin composites, and Real (c) and imaginary (d) part of permeability of F/G-paraffin composites. Fig. 11 Plots of µ″(µ′)-2f -1 versus f for F/G.

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Fig. 12 Summarization of EM wave absorption mechanisms for F/G-paraffin

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composites. Fig. 13 (a) dielectric tangent loss and (b) magnetic tangent loss of the F/G-paraffin composites.

Table Captions:

Table 1 Comparison of EM absorption properties of this work and other representative works.

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30 25 50 25 50 20 60 50 50

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graphene/Fe3O4 graphene/BaFe12O19/CaFe2O4/CoFe2O4 graphene/BaFe12O19/CoFe2O4 graphene/Fe3O4/CMT graphene/BaFe12O19–Ni0.8Zn0.2Fe2O4 graphene/Fe3O4 CoFe2O4/graphene α-Fe2O3/reduced graphene oxide Fe3O4/reduced graphene oxide

loading ratio(wt %)

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2.5 2.0 1.8 1.8

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Synthesis and electromagnetic wave absorption properties of matrimony vine-like Iron oxide/reduced graphene oxide

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prepared by a facile method Hai-rong Chu, a Qiang Zeng, a Ping Chen, *a Qi Yu, *b Dong-wei Xu, a Xu-hai Xiong, b Qi Wang b a.

State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian (116024), China

E-Mail: [email protected] b.

Liaoning Key laboratory of advanced polymer matrix composites, Shenyang Aerospace University,

Shenyang (110136), China

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E-Mail: [email protected]

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Highlights:  Matrimony vine-like α-Fe2O3/reduced graphene oxide was prepared by facile and scalable method.  By annealing treatment, α-Fe2O3/reduced graphene oxide was converted into Fe3O4/reduced graphene oxide.  The obtained products both show enhanced electromagnetic wave absorption properties.  Fe3O4/reduced graphene oxide absorber can be used in harsh environment.