scholarly journals Joining Caffeic Acid and Hydrothermal Treatment to Produce Environmentally Benign Highly Reduced Graphene Oxide

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 732
Author(s):  
Ana Barra ◽  
Oana Lazăr ◽  
Aida Pantazi ◽  
María J. Hortigüela ◽  
Gonzalo Otero-Irurueta ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Caffeic Acid ◽  
Reduced Graphene Oxide ◽  
Cost Effective ◽  
Hydrothermal Conditions ◽  
Carbon Particles ◽  
Transmission Electron ◽  
Reduced Graphene ◽  
Wide Range ◽  
Scanning Transmission

Reduced graphene oxide (rGO) is a promising graphene-based material, with transversal applicability to a wide range of technological fields. Nevertheless, the common use of efficient—but hazardous to environment and toxic—reducing agents prevents its application in biological and other fields. Consequently, the development of green reducing strategies is a requirement to overcome this issue. Herein, a green, simple, and cost-effective one-step reduction methodology is presented. Graphene oxide (GO) was hydrothermally reduced in the presence of caffeic acid (CA), a natural occurring phenolic compound. The improvement of the hydrothermal reduction through the presence of CA is confirmed by XRD, Raman, XPS and TGA analysis. Moreover, CA polymerizes under hydrothermal conditions with the formation of spherical and non-spherical carbon particles, which can be useful for further rGO functionalization. FTIR and XPS confirm the oxygen removal in the reduced samples. The high-resolution scanning transmission electron microscopy (HRSTEM) images also support the reduction, showing rGO samples with an ordered graphitic layered structure. The promising rGO synthesized by this eco-friendly methodology can be explored for many applications.

scholarly journals Facile Fabrication of CeO2/Electrochemically Reduced Graphene Oxide Nanocomposites for Vanillin Detection in Commercial Food Products

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1356 ◽  
Author(s):  
Xue Nie ◽  
Rui Zhang ◽  
Zheng Tang ◽  
Haiyan Wang ◽  
Peihong Deng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Linear Sweep Voltammetry ◽  
X Ray ◽  
Transmission Electron ◽  
Reduced Graphene ◽  
Electrochemically Reduced Graphene Oxide ◽  
Wide Range ◽  
Facile Fabrication

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.

One-Step Solvothermal Synthesis of Tetranitro-Cobalt Phthalocyanine/Reduced Graphene Oxide Composite

NANO ◽  
2015 ◽  
Vol 10 (03) ◽  
pp. 1550045 ◽  
Author(s):  
Lijuan Zhang ◽  
Hejun Li ◽  
Qiangang Fu ◽  
Zhanwei Xu ◽  
Kezhi Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Rotating Disk ◽  
Rotating Disk Electrode ◽  
Cobalt Phthalocyanine ◽  
Transmission Electron ◽  
Reduced Graphene ◽  
Wide Range ◽  
One Step

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.

scholarly journals Applicability of Goethite/Reduced Graphene Oxide Nanocomposites to Remove Lead from Wastewater

Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1580
Author(s):  
Franklin Gordon-Nuñez ◽  
Katherine Vaca-Escobar ◽  
Milton Villacís-García ◽  
Lenys Fernández ◽  
Alexis Debut ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Adsorption Capacity ◽  
Reduced Graphene Oxide ◽  
Lead Ion ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Reduced Graphene ◽  
Scanning Transmission ◽  
Efficient Alternative

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).

scholarly journals Paper-based potentiometric sensing devices modified with chemically reduced graphene oxide (CRGO) for trace level determination of pholcodine (opiate derivative drug)

RSC Advances ◽  
2021 ◽  
Vol 11 (20) ◽  
pp. 12227-12234
Author(s):  
Hisham S. M. Abd-Rabboh ◽  
Abd El-Galil E. Amr ◽  
Elsayed A. Elsayed ◽  
Ahmed Y. A. Sayed ◽  
Ayman H. Kamel
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Cost Effective ◽  
Trace Level ◽  
Ion Sensing ◽  
Reduced Graphene ◽  
Chemically Reduced Graphene Oxide ◽  
Trace Level Determination ◽  
Analytical Device

Robust, reliable and cost-effective paper-based analytical device for potentiometric pholcodine (opiate derivative drug) ion sensing has been prepared and characterized.

Tuning the cationic ratio of Fe1CoxNiyP integrated on Vertically aligned reduced graphene oxide array via electroless plating as efficient self-supported bifunctional electrocatalyst for water splitting

2021 ◽  
pp. 1-33
Author(s):  
Kaiming Guo ◽  
Firdoz Shaik ◽  
Jine Yang ◽  
Bin Jiang
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Water Splitting ◽  
Electroless Plating ◽  
Cost Effective ◽  
Bifunctional Electrocatalyst ◽  
Reduced Graphene ◽  
Wide Ph Range ◽  
Vertically Aligned ◽  
Ph Range

Abstract Water splitting is considered as a potential sustainable and green technology for producing mass hydrogen and oxygen. A cost-effective self-supported stable electrocatalyst with excellent electrocatalytic performance in a wide pH range is greatly required for water splitting. This work reports on the synthesis and anchoring of Fe1CoxNiyP nanoparticles on vertically aligned reduced graphene oxide array (VrGO) via electroless plating. The catalytic activity of Fe1CoxNiyP nanoparticles is tuned finely by tailoring the cationic ratio of Co and Ni. Fe1Co2Ni1P/VrGO exhibits the lowest overpotential (58 and 110 mV) at 10 mA cm−2 and lowest tafel slope (31 and 33 mV dec−1) for hydrogen evolution reaction in 1.0 M KOH and 0.5 M H2SO4 respectively. Fe1Co1Ni2P/VrGO exhibits the lowest overpotential (173 mV) at 10 mA cm−2 with lowest tafel slope (47 mV dec-1) for oxygen evolution reaction. The enhanced performance of the electrocatalyst is attributed to improved electrical conductivity, synergistic effects and beneficial electronic states caused by the appropriate atomic ratio of Co and Ni in the bifunctional electrocatalyst. This study helps to explore the effect of variable cationic ratio in the cost-effective ternary iron group metal phosphides electrocatalysts to achieve enhanced electrocatalytic performance for water splitting in a wide pH range.

Self-propagated combustion synthesis of few-layered graphene: an optical properties perspective

Nanoscale ◽  
2018 ◽  
Vol 10 (16) ◽  
pp. 7581-7588 ◽  
Author(s):  
Manonmani Mohandoss ◽  
Soujit Sen Gupta ◽  
Ramesh Kumar ◽  
Md Rabiul Islam ◽  
Anirban Som ◽  
...  
Keyword(s):  
Optical Properties ◽  
Graphene Oxide ◽  
Combustion Synthesis ◽  
Reduced Graphene Oxide ◽  
Cost Effective ◽  
Effective Strategy ◽  
Cost Effective Strategy ◽  
Reduced Graphene

This paper describes a labour-efficient and cost-effective strategy to prepare few-layered reduced graphene oxide like sheets from graphite.

scholarly journals Reduced Graphene Oxide–Epoxy Grafted Poly(Styrene-Co-Acrylate) Composites for Corrosion Protection of Mild Steel

Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 666
Author(s):  
Xinchuan Fan ◽  
Yue Hu ◽  
Yijun Zhang ◽  
Jiachen Lu ◽  
Xiaofeng Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
X Ray Diffraction ◽  
Corrosion Properties ◽  
X Ray ◽  
Transmission Electron ◽  
Reduced Graphene ◽  
Scanning Electron

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.

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