Electro-Magnetic Wave Absorbing Properties Study of Nano-Composites Based on Fe3O4

2021 ◽  
Vol 13 (3) ◽  
pp. 447-454
Author(s):  
Yihan Jin ◽  
Xi Luo ◽  
Jinglin Zhang ◽  
Yipeng Yu ◽  
Jing An ◽  
...  

Chemical coprecipitation method, hydrothermal method and micro-emulsion method were adopted to prepare pure Fe3O4 (X1) magnetic nano-particles, reduced graphene oxide-Fe3O4 (X2) binary composites and reduced graphene oxide-Fe3O4-polyaniline (X3) ternary composites. The morphology, structure and magnetic performance were characterized by X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM) and vibration sample magnetism (VSM). The result of TEM showed that Fe3O4 nano-particles distributed uniformly on the surface of graphene and PANI matrix and the mean size was bout 13~14 nm. The electromagnetic data was tested by vector network analyzer demonstrating that the minnimum reflection loss (RLmin) value of X3 was -53.94 dB at 16.1 GHz with 1.5 mm thickness and 3.82 GHz (14.18~18 GHz) absorbing bandwidth (RL<italic/>-10 dB). Compared with pure magnetic Fe3O4 powders and rGO-Fe3O4 binary composites, the rGO-Fe3O4-PANI ternary composites were conduced to a great reinforce of the electro-magnetic wave absorbing properties and absorbing bandwidth.

2021 ◽  
Vol 13 (3) ◽  
pp. 473-480
Author(s):  
Yihan Jin ◽  
Xi Luo ◽  
Jinglin Zhang ◽  
Dongliang Zhao ◽  
Kewei Gao

Micro-emulsion method is adopted to synthesis rGO-Fe3O4-PANI (reduced graphene oxide-Fe3O4-polyaniline) ternary nano-composites. With the different contents of aniline (0.1 g, 0.2 g, 0.3 g) added in production, the corresponding final products are named as sample 1, sample 2, sample 3, respectively. The results of TEM indicate that the mean size of Fe3O4 nano-particles is 14 nm and they are anchored onto rGO slice. There are some PANI polymer wrinkles distributed on the rGO surface uniformly. The electro-magnetic data demonstrate that sample 1 possess a great enhancement of the electro-magnetic wave absorption abilities and frequency bandwidth among the three samples. The RLmin (minimum reflection loss) value of sample 1 is -44.16 dB at 4.29 GHz with 5 mm coating thickness and 1.77 GHz (3.72-4.94 GHz, 13.33-13.88 GHz) frequency bandwidth (RL <italic/> -10 dB). We can believe that this kind of nano-composites will have a promising application in the future.


Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 666
Author(s):  
Xinchuan Fan ◽  
Yue Hu ◽  
Yijun Zhang ◽  
Jiachen Lu ◽  
Xiaofeng Chen ◽  
...  

Reduced graphene oxide–epoxy grafted poly(styrene-co-acrylate) composites (GESA) were prepared by anchoring different amount of epoxy modified poly(styrene-co-acrylate) (EPSA) onto reduced graphene oxide (rGO) sheets through π–π electrostatic attraction. The GESA composites were characterized by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The anti-corrosion properties of rGO/EPSA composites were evaluated by electro-chemical impedance spectroscopy (EIS) in hydroxyl-polyacrylate coating, and the results revealed that the corrosion rate was decreased from 3.509 × 10−1 to 1.394 × 10−6 mm/a.


Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1356 ◽  
Author(s):  
Xue Nie ◽  
Rui Zhang ◽  
Zheng Tang ◽  
Haiyan Wang ◽  
Peihong Deng ◽  
...  

In this paper, CeO2 nanoparticles were synthesized by the solvothermal method and dispersed uniformly in graphene oxide (GO) aqueous solution by ultrasonication. The homogeneous CeO2-GO dispersion was coated on the surface of a glassy carbon electrode (GCE), and the CeO2/electrochemically reduced graphene oxide modified electrode (CeO2/ERGO/GCE) was obtained by potentiostatic reduction. The results of X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) showed that CeO2 nanocrystals were uniformly coated by gossamer like ERGO nanosheets. The electrochemical behavior of vanillin on the CeO2/ERGO/GCE was studied by cyclic voltammetry (CV). It was found that the CeO2/ERGO/GCE has high electrocatalytic activity and good electrochemical performance for vanillin oxidation. Using the second derivative linear sweep voltammetry (SDLSV), the CeO2/ERGO/GCE provides a wide range of 0.04–20 µM and 20 µM–100 µM for vanillin detection, and the detection limit is estimated to be 0.01 µM after 120 s accumulation. This method has been successfully applied to the vanillin detection in some commercial foods.


2020 ◽  
Vol 8 (38) ◽  
pp. 20111-20121
Author(s):  
Yinze Zuo ◽  
Yuejin Zhu ◽  
Qi Wang ◽  
Kezhong Lv ◽  
Weiming Su ◽  
...  

A novel strategy for suppressing the “shuttle effect” of LiPSs and facilitating reaction kinetics is achieved using the reduced graphene oxide (rGO) with incorporated polar LiNiPO4 (LNPO) nano-particles as functional coating layer for separator.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Fatin Saiha Omar ◽  
Huang Nay Ming ◽  
Syed Muhamad Hafiz ◽  
Lim Hong Ngee

This work reports on synthesis of zinc oxide/reduced graphene oxide (ZnO/rGO) nanocomposites in the presence of diethylenetriamine (DETA) via a facile microwave method. The X-ray diffraction (XRD) patterns of the nanocomposites correspond to the ZnO hexagonal phase wurtzite structure. The high-resolution transmission electron microscopy (HRTEM) images revealed that the ZnO nanorods, with an average length : diameter ratio of 10, were successfully deposited on the rGO sheets. Under the irradiation of sunlight, the nanocomposites showed enhanced adsorption-photocatalysis by more than twofold and photocurrent response by sixfold compared to the ZnO. The excellent photoactivity performance of the nanocomposites is contributed by smaller ZnO nanorod and the presence of rGO that acts as a photosensitizer by transferring electrons to the conduction band of ZnO within the nanocomposite during sunlight illumination.


2018 ◽  
Vol 5 (8) ◽  
pp. 180613 ◽  
Author(s):  
Haijin Liu ◽  
Peiyao Li ◽  
Haokun Bai ◽  
Cuiwei Du ◽  
Dandan Wei ◽  
...  

Anatase TiO 2 with {001} facets is much more active than that with {101} facets, which has been verified via experiments and theoretical calculations. Graphene has garnered much attention since it was initially synthesized, due to its unique properties. In this study, reduced graphene oxide (RGO)/{001} faceted TiO 2 composites were fabricated via a solvothermal method. The composites were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectrophotometry, photoluminescence and Raman analysis. The results revealed that the graphene oxide was reduced during the preparation process of the {001} faceted TiO 2 , and combined with the surface of {001} TiO 2 . The photocatalytic activities of the composites were evaluated through the degradation of basic violet, under both white light ( λ > 390 nm) and visible light ( λ = 420 nm) irradiation. The results indicated that the photocatalytic activities of the {001} faceted TiO 2 were significantly improved following the incorporation of RGO, particularly under visible light irradiation. Theoretical calculations showed that the band structure of the {001} faceted TiO 2 was modified via graphene hybridization, where the separation of photoinduced electron–hole pairs was promoted; thus, the photocatalytic activity was enhanced.


NANO ◽  
2015 ◽  
Vol 10 (03) ◽  
pp. 1550045 ◽  
Author(s):  
Lijuan Zhang ◽  
Hejun Li ◽  
Qiangang Fu ◽  
Zhanwei Xu ◽  
Kezhi Li ◽  
...  

Tetranitro-cobalt phthalocyanine/reduced graphene oxide (TNCoPc/RGO) composite was prepared using ethylene glycol as reducing agent and precursor. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FT-IR) were used to characterize the composite. The electrochemical performance of the composite was examined by cyclic voltammetry and rotating disk electrode. The SEM observation and UV-Vis absorption spectrophotometer reveal that TNCoPc nanoparticles are closely contacted with RGO. The results show that the composite has a larger peak current and a higher current density than TNCoPc for oxygen reduction in an alkaline medium. This work offers a simple and environmental route for the synthesis of metal phthalocyanine (MPc)/RGO, which is adaptable to a wide range of applications in fuel cells.


Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 724 ◽  
Author(s):  
Bingkai Han ◽  
Meixin Pan ◽  
Jiexin Zhou ◽  
Yingying Wang ◽  
Zihua Wang ◽  
...  

The use of graphene has leapt forward the materials field and the functional modification of graphene has not stopped. In this work, β-lactoglobulin (BLG) was used to functionalize reduced graphene oxide (RGO) based on its amphiphilic properties. Also, trimetallic PtAuPd nanoparticles were reduced to the surface of BLG-functionalized RGO and formed BLG-PtAuPd-RGO nanocomposite using facile synthesis. Transmission electron microscopy, energy-dispersive X-ray spectroscopy and Fourier transform infrared spectra were used to characterize the nanocomposite. Electrocatalytic analysis was evaluated through cyclic voltammetry and chronoamperometry methods. We developed a glucose sensor by fabricating GOD-BLG-PtAuPd-RGO/glassy carbon (GC) electrode. It presented a remarkable sensitivity of 63.29 μA mM−1 cm−2 (4.43 μA mM−1), a wider linear range from 0.005 to 9 mM and a lower detection limit of 0.13 μM (S/N = 3). Additionally, the glucose sensor exhibited excellent testing capability in human serum samples.


NANO ◽  
2014 ◽  
Vol 09 (03) ◽  
pp. 1450031
Author(s):  
MEILING ZOU ◽  
HAN ZHU ◽  
PAN WANG ◽  
SHIYONG BAO ◽  
MINGLIANG DU ◽  
...  

In this paper, epigallocatechin gallate (EGCG) was used as a green reductant both for the fabrication of soluble reduced graphene oxide (rGO) and the synthesis of Au nanoparticles/rGO nanocomposite. Fourier transform infrared (FTIR) spectra confirmed the efficient removal of the oxygen-containing groups in graphene oxide (GO) through the reduction act of EGCG. Au nanoparticles ( AuNPs ) were anchored onto the rGO sheets by heating the mixed solution of rGO and chloroauric acid at 65°C using EGCG as reductant. Transmission electron microscopy (TEM), atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS) were employed to characterize the resulting nanocomposite. Due to the chelating effect of polyhydroxy EGCG, AuNPs with diameters of ~20–50 nm were stably decorated onto both sides of the rGO sheets. Because this reduction method avoids the use of toxic reagents, AuNPs /rGO nanocomposite would be eco-friendly, and it might be useful not only for electronic devices but also for biocompatible materials in the future applications.


2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Huali Zhang ◽  
Wen Liu ◽  
Linqing Yang ◽  
Jun Liu ◽  
Yunfei Wang ◽  
...  

Graphene is an excellent platform to support and stabilize silver nanoparticles (AgNPs). The reduced graphene oxide-silver nanoparticles (rGO-AgNPs) were synthesized by the chemical reduction method and characterized by using ultraviolet-visible (UV-vis) absorption, transmission electron microscopy (TEM), X-ray diffractometer (XRD), and scanning probe microscopy (SPM). The binding reaction of rGO-AgNPs with bovine serum albumin (BSA) was investigated by using fluorescence spectrometry and SPM. As the concentration of AgNPs increased, the fluorescence spectrum was quenched, and the quenching process of rGO-AgNPs and BSA was static quenching. Thermodynamic parameters of the absorption process were evaluated at different temperatures, and the negative values of Gibbs free energy (ΔG) showed that this process was spontaneous. The main type of interaction was hydrophobic interaction according to the values of changes in standard enthalpy (ΔH) and entropy (ΔS). In addition, the morphology changes of proteins interacting with nanomaterials were detected by SPM.


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