scholarly journals Localized resistance measurements of wrinkled reduced graphene oxide using in-situ transmission electron microscopy

Carbon ◽  
2017 ◽  
Vol 113 ◽  
pp. 340-345 ◽  
Author(s):  
Hanna M. Nilsson ◽  
Ludvig de Knoop ◽  
John Cumings ◽  
Eva Olsson
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.


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.


2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Xiaojuan Zhang ◽  
Wenbin Cai ◽  
Lingyun Hao ◽  
Suli Feng ◽  
Qing Lin ◽  
...  

The Fe3O4/reduced graphene oxide (Fe3O4/RGO) nanocomposites with good dispersibility were synthesized for targeted delivery of paclitaxel (PTX). Firstly, the superparamagnetic Fe3O4/functional GO nanocomposites were prepared via hydrothermal method in which GO sheets were modified by surfactant wrapping. The Fe3O4/RGO nanocomposites were successively prepared through the reduction of graphene oxide. The products were investigated by Fourier-transform infrared spectrum, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, and vibration sample magnetometry. It was found that spherical Fe3O4 nanoparticles were uniformly anchored over the RGO matrix and the nanocomposites were superparamagnetic with saturation magnetization (Ms) of 9.39 emu/g. Then PTX was loaded onto Fe3O4/RGO nanocomposites, and the drug loading capacity was 67.9%. Cell viability experiments performed on MCF-7 demonstrated that the Fe3O4/RGO-loaded PTX (Fe3O4/RGO/PTX) showed cytotoxicity to MCF-7, whereas the Fe3O4/RGO displayed no obvious cytotoxicity. The above results indicated that Fe3O4/RGO/PTX nanocomposites had potential application in tumor-targeted chemotherapy.


2010 ◽  
Vol 148-149 ◽  
pp. 1571-1574
Author(s):  
Qing Li Hao ◽  
Jiao Tian ◽  
Hua Lan Wang ◽  
Xin Wang

The ordered polyaniline nanoarrays had dispersed homogeneously on the graphene oxide or reduced graphene oxide sheets without agglomeratation in isopropanol media. The composites were characterized by field emission scanning electron microscopy, transmission electron microscopy, infrared spectroscopy, Raman spectroscopy and electrochemical tests. The electrochemical performance of the electrode material had been dramatically improved with the highest specific capacitance of 1351 F/g.


Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1580
Author(s):  
Franklin Gordon-Nuñez ◽  
Katherine Vaca-Escobar ◽  
Milton Villacís-García ◽  
Lenys Fernández ◽  
Alexis Debut ◽  
...  

Lead ion in drinking water is one of the most dangerous metals. It affects several systems, such as the nervous, gastrointestinal, reproductive, renal, and cardiovascular systems. Adsorption process is used as a technology that can solve this problem through suitable composites. The adsorption of lead (Pb(II)) on graphene oxide (GO) and on two goethite (α-FeOOH)/reduced graphene oxide (rGO) composites (composite 1: 0.10 g GO: 22.22 g α-FeOOH and composite 2: 0.10 g GO: 5.56 g α-FeOOH), in aqueous medium, was studied. The GO was synthesized from a commercial pencil lead. Composites 1 and 2 were prepared from GO and ferrous sulfate. The GO and both composites were characterized by using scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM), Raman spectroscopy, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and dynamic light scattering (DLS). The adsorption capacity of Pb(II) on the GO and both composites was evaluated through adsorption isotherms. Composite 1 presented a significant agglomeration of α-FeOOH nanorods on the reduced graphene oxide layers. Meanwhile, composite 2 exhibited a more uniform distribution of nanorods. The adsorption of Pb(II) on the three adsorbents fits the Langmuir isotherm, with an adsorption capacity of 277.78 mg/g for composite 2200 mg/g for GO and 138.89 mg/g for composite 1. Composite 2 emerged as a highly efficient alternative to purify water contaminated with Pb(II).


Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 687 ◽  
Author(s):  
Anton Smirnov ◽  
Nestor Washington Solís Pinargote ◽  
Nikita Peretyagin ◽  
Yuri Pristinskiy ◽  
Pavel Peretyagin ◽  
...  

In this work, we report an available technique for the effective reduction of graphene oxide (GO) and the fabrication of nanostructured zirconia reduced graphene oxide powder via a hydrothermal method. Characterization of the obtained nano-hybrid structure materials was carried out using a scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR). The confirmation that GO was reduced and the uniform distribution of zirconia nanoparticles on graphene oxide sheets during synthesis was obtained due to these techniques. This has presented new opportunities and prospects to use this uncomplicated and inexpensive technique for the development of zirconia/graphene nanocomposite powders.


2021 ◽  
Author(s):  
Kartik Tantubay ◽  
Piu Das ◽  
Moni Baskey (Sen)

Abstract Zinc chromite nanoparticles (NPs) and zinc chromite-reduced graphene oxide (ZnCr2O4-rGO) nanocomposite have been synthesized by the combined effect of reflux condensation and calcination process. The structural properties were characterised by X-ray diffraction (XRD), Fourier transform infrared (FTIR), UV-visible studies etc. Structural morphology was investigated by field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) that indicates the formation of particles in nanometre regime. The catalytic effects of synthesized materials were studied in presence of visible light assisted by hydrogen peroxide (H2O2) and they show excellent photo activity which supports the band gap value and photoluminescence outcome. The presence of the elements Zn, Cr, O and C has been confirmed by Energy dispersive X-ray spectroscopy (EDX) images which show the purity of the synthesized products.


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