scholarly journals Synthesis and Characterization of Reduced Graphene Oxide (rGO) Started from Graphene Oxide (GO) Using the Tour Method with Different Parameters

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Adere Tarekegne Habte ◽  
Delele Worku Ayele
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Potassium Permanganate ◽  
Chemical Reduction ◽  
Volume Ratio ◽  
Graphite Powder ◽  
Green Approach ◽  
Synthesis Strategy ◽  
Reduced Graphene ◽  
Diffraction Patterns

A new approach to synthesize graphene is oxidizing graphite powder with a mixture of H2SO4/H3PO4 acids and potassium permanganate. Parameters such as reaction time, reaction temperature, and amount of concentration were varied to study the degree of oxidation of graphite to graphene oxide. Currently, an improved method for the preparation of graphene oxide was the most common one. A mixture of H2SO4/H3PO4 (9 : 1 volume ratio) instead of only H2SO4 resulted in increased hydrophilic and oxidized GO without the emission of toxic gas, which differs from the traditional Hummers’ method. The graphene oxide (GO) was converted to reduced graphene oxide (rGO) by chemical reduction using ascorbic acid as the reducing agent. The GO and rGO were characterized by UV-visible spectroscopy, FTIR spectroscopy, and X-ray diffraction patterns. The result showed that treating graphite powder with potassium permanganate (1 : 9) and a mixture of concentrated H2SO4/H3PO4 acids at 50°C for 12 hours resulted in a better oxidation degree. The designed synthesis strategy could be easily controlled and is an alternative green approach for the production of graphene oxide and reduced graphene oxide.

Ultrasonic Assisted Synthesis of Reduced Graphene Oxide in Glucose Solution

2016 ◽  
Vol 708 ◽  
pp. 25-29
Author(s):  
Ainnur Izzati Kamisan ◽  
Lili Widarti Zainuddin ◽  
Ainnur Sherene Kamisan ◽  
T.I.T. Kudin ◽  
Oskar Hasdinor Hassan ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Graphite Oxide ◽  
Glucose Solution ◽  
Graphite Powder ◽  
Green Approach ◽  
Reduced Graphene ◽  
Mild Reduction ◽  
Ultrasonic Assisted ◽  
Device Applications

A new carbon material viz. graphene has been attracted an increasing research interest owing to its unique electrical and mechanical properties that is useful for the various device applications. The synthesis of graphene from graphene oxide usually involves harmful chemical reducing agents that are toxic and undesirable to human and the environment. By avoiding the use of toxic and environmentally harmful reductants, we report a green approach to effectively reduce graphene oxide to graphene in glucose solution at room temperature. Graphite oxide was synthesized from graphite powder using modified Hummers’ method. Graphite oxide then further exfoliated to graphene oxide by using ultrasonic irradiation. The mild reduction of graphene oxide is carried out by mixing graphene oxide solution with glucose. The reduction time is varied with 15, 30, 45 and 60 minutes. TEM images provide clear evidence for the formation of few layer graphene. Characterization of theresulting glucose reduced graphene oxide by FTIR indicates the partial removal of oxygen-containing functional groups from the surface of graphene oxide and formation of graphene with defects.

Effect of Chemical Reduction Temperature on Optical Properties of Reduced Graphene Oxide (rGO) and its Potentials Supercapacitor Device

2017 ◽  
Vol 901 ◽  
pp. 55-61 ◽  
Author(s):  
Haris Suhendar ◽  
Ahmad Kusumaatmaja ◽  
Kuwat Triyana ◽  
Iman Santoso
Keyword(s):  
Optical Properties ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Chemical Reduction ◽  
Epoxy Group ◽  
Electrical Energy ◽  
Graphite Powder ◽  
Reduction Temperature ◽  
Reduced Graphene ◽  
Vis Spectroscopy

Reduced graphene oxide (rGO) has been successfully synthesized from graphite powder using Hummer’s Method. The epoxy group in GO structure was reduced by hydrazine 80 wt% at a temperature of 70o, 80o, and 90°C. The optical properties of produced rGO were characterized by using Uv-Vis and FTIR spectrometer. From Uv-Vis spectroscopy we observe that the absorbance of rGO decreased as increasing the reduction temperature. This is because the higher reduction temperature yields a high degree of rGO defect. The rGO produced at a reduction temperature of 70oC has very close similiraties absorbance spectrum with rGO produced by Sigma Aldrich Company. The Uv-Vis absorbance of rGO was used to calculated optical constant, and by using Kramers-Kronig relation we got refractive index values of rGO. The decreasing of absorbance may also stem out from the reducing of C=C bonding with sp2 hybridization due to the presence of energetic Hydrazine as indicated by the decrease of FTIR spectrum at ~1600 cm-1. Our produced rGO then used to fabricated the supercapacitor device with a mass of 0,03 gram using Polivinyl Alcohol (PVA) as a binder. From cyclic voltammetry measurement, we obtain the specific capacitance of our rGO-based supercapacitor is 2.45 F which is still in the category of supercapacitive although the optimization of rGO and PVA composition is still required. Our result shows the exciting potential of rGO based supercapacitor as electrical energy storage.

scholarly journals Obtaining of Reduced Graphene Oxide from Graphite by using Hummer’s and Chemical Reduction Method

2019 ◽  
Vol 2 (3) ◽  
pp. 601-605
Author(s):  
Kübra Yıldız ◽  
Muhammet Uzun
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Reduction Method ◽  
Chemical Reduction ◽  
Graphite Powder ◽  
Chemical Reduction Method ◽  
Graphene Oxides ◽  
Hummers Method ◽  
Reduced Graphene ◽  
Modified Hummers Method

In this study, graphene oxide (GO) was synthesized from graphite using modified Hummers method. According to other methods known in the literature, modified Hummers method; it is simpler and less costly in terms of process steps. In addition, it is safer and environmentally friendly than the Hummers method. Reduced Graphene Oxide (RGO) was obtained by reduction of graphene oxides (GO) synthesized by modified Hummers method. It is understood from the obtained results that GO is synthesized successfully from graphite powder by modified Hummers method and RGO is obtained successfully by reduction of graphene oxides (GO).

scholarly journals A Facile and Green Synthesis of a MoO2-Reduced Graphene Oxide Aerogel for Energy Storage Devices

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 594 ◽  
Author(s):  
Mara Serrapede ◽  
Marco Fontana ◽  
Arnaud Gigot ◽  
Marco Armandi ◽  
Glenda Biasotto ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Chemical Reduction ◽  
Low Cost ◽  
Xps Analysis ◽  
3D Scaffold ◽  
Energy Storage Devices ◽  
Reduced Graphene

A simple, low cost, and “green” method of hydrothermal synthesis, based on the addition of l-ascorbic acid (l-AA) as a reducing agent, is presented in order to obtain reduced graphene oxide (rGO) and hybrid rGO-MoO2 aerogels for the fabrication of supercapacitors. The resulting high degree of chemical reduction of graphene oxide (GO), confirmed by X-Ray Photoelectron Spectroscopy (XPS) analysis, is shown to produce a better electrical double layer (EDL) capacitance, as shown by cyclic voltammetric (CV) measurements. Moreover, a good reduction yield of the carbonaceous 3D-scaffold seems to be achievable even when the precursor of molybdenum oxide is added to the pristine slurry in order to get the hybrid rGO-MoO2 compound. The pseudocapacitance contribution from the resulting embedded MoO2 microstructures, was then studied by means of CV and electrochemical impedance spectroscopy (EIS). The oxidation state of the molybdenum in the MoO2 particles embedded in the rGO aerogel was deeply studied by means of XPS analysis and valuable information on the electrochemical behavior, according to the involved redox reactions, was obtained. Finally, the increased stability of the aerogels prepared with l-AA, after charge-discharge cycling, was demonstrated and confirmed by means of Field Emission Scanning Electron Microscopy (FESEM) characterization.

Chemically reduced graphene oxide-coated knitted fabric imparted conductivity and outstanding hydrophobicity

2021 ◽  
pp. 004051752199547
Author(s):  
Min Hou ◽  
Xinghua Hong ◽  
Yanjun Tang ◽  
Zimin Jin ◽  
Chengyan Zhu ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Chemical Reduction ◽  
Knitted Fabric ◽  
Mesh Structure ◽  
Reduced Graphene ◽  
Chemically Reduced Graphene Oxide ◽  
Modified Hummers Method

Functionalized knitted fabric, as a kind of flexible, wearable, and waterproof material capable of conductivity, sensitivity and outstanding hydrophobicity, is valuable for multi-field applications. Herein, the reduced graphene oxide (RGO)-coated knitted fabric (polyester/spandex blended) is prepared, which involves the use of graphite oxide (GO) by modified Hummers method and in-situ chemical reduction with hydrazine hydrate. The treated fabric exhibits a high electrical conductivity (202.09 S/cm) and an outstanding hydrophobicity (140°). The outstanding hydrophobicity is associated with the morphology of the fabric and fiber with reference to pseudo-infiltration. These properties can withstand repeated bending and washing without serious deterioration, maintaining good electrical conductivity (35.70 S/cm) and contact angle (119.39°) after eight standard washing cycles. The material, which has RGO architecture and continuous loop mesh structure, can find wide use in smart garment applications.

Mesoporous titanosilicate/reduced graphene oxide composites: layered structure, high surface-to-volume ratio, doping effect and application in dye removal from water

2012 ◽  
Vol 22 (38) ◽  
pp. 20504 ◽  
Author(s):  
Thuy-Duong Nguyen-Phan ◽  
Eun Woo Shin ◽  
Viet Hung Pham ◽  
Hyukmin Kweon ◽  
Sunwook Kim ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Layered Structure ◽  
Dye Removal ◽  
High Surface ◽  
Volume Ratio ◽  
Doping Effect ◽  
Reduced Graphene ◽  
Oxide Composites

Waterborne reduced graphene oxide dispersed bio-polyesteramide nanocomposites: an approach towards eco-friendly anticorrosive coatings

2019 ◽  
Vol 43 (12) ◽  
pp. 4706-4720 ◽  
Author(s):  
Mohd Irfan ◽  
Shahidul Islam Bhat ◽  
Sharif Ahmad
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Low Cost ◽  
Green Approach ◽  
Anticorrosive Coatings ◽  
Reduced Graphene

RGO dispersed waterborne soy polyester amide nanocomposites were formulated utilizing a solventless VOC free green approach for use as low cost anticorrosive coatings.

scholarly journals Chemical and structural properties of reduced graphene oxide—dependence on the reducing agent

2020 ◽  
Vol 56 (5) ◽  
pp. 3738-3754
Author(s):  
B. Lesiak ◽  
G. Trykowski ◽  
J. Tóth ◽  
S. Biniak ◽  
L. Kövér ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Sodium Borohydride ◽  
Reduction Rate ◽  
Graphite Powder ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Vacancy Defects ◽  
Group Reduction ◽  
Reduced Graphene

AbstractGraphene oxide (GO) prepared from graphite powder using a modified Hummers method and reduced graphene oxide (rGO) obtained from GO using different reductants, i.e., sodium borohydride, hydrazine, formaldehyde, sodium hydroxide and L-ascorbic acid, were investigated using transmission electron microscopy, X-ray diffraction, Raman, infrared and electron spectroscopic methods. The GO and rGOs’ stacking nanostructure (flake) size (height x diameter), interlayer distance, average number of layers, distance between defects, elementary composition, content of oxygen groups, C sp3 and vacancy defects were determined. Different reductants applied to GO led to modification of carbon to oxygen ratio, carbon lattice (vacancy) and C sp3 defects with various in-depth distribution of C sp3 due to oxygen group reduction proceeding as competing processes at different rates between interstitial layers and in planes. The reduction using sodium borohydride and hydrazine in contrary to other reductants results in a larger content of vacancy defects than in GO. The thinnest flakes rGO obtained using sodium borohydride reductant exhibits the largest content of vacancy, C sp3 defects and hydroxyl group accompanied by the smallest content of epoxy, carboxyl and carbonyl groups due to a mechanism of carbonyl and carboxyl group reduction to hydroxyl groups. This rGO similar diameter to GO seems to result from a predominant reduction rate between the interstitial layers. The thicker flakes of a smaller diameter than in GO are obtained in rGOs prepared using remaining reductants and result from a higher rate of reduction of in plane defects.

scholarly journals Real-time monitored photocatalytic activity and electrochemical performance of an rGO/Pt nanocomposite synthesized via a green approach

RSC Advances ◽  
2020 ◽  
Vol 10 (23) ◽  
pp. 13722-13731 ◽  
Author(s):  
Satish Kasturi ◽  
Sri Ramulu Torati ◽  
Yun Ji Eom ◽  
Syafiq Ahmad ◽  
Byong-June Lee ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Graphene Oxide ◽  
Electrochemical Performance ◽  
Ambient Temperature ◽  
Real Time ◽  
Reduced Graphene Oxide ◽  
Organic Pollutant ◽  
Green Approach ◽  
Reduced Graphene

Herein, we have reported the real-time photodegradation of methylene blue, an organic pollutant, in the presence of sunlight at an ambient temperature using a platinum-decorated reduced graphene oxide (rGO/Pt) nanocomposite.

scholarly journals Elucidating the Chemistry behind the Reduction of Graphene Oxide Using a Green Approach with Polydopamine

Nanomaterials ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 902 ◽  
Author(s):  
Cláudia Silva ◽  
Frank Simon ◽  
Peter Friedel ◽  
Petra Pötschke ◽  
Cordelia Zimmerer
Keyword(s):  
Raman Spectroscopy ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
New Approach ◽  
Oh Groups ◽  
Chemical Treatments ◽  
Green Approach ◽  
Reduced Graphene ◽  
Thermal And Electrical Properties

A new approach using X-ray photoelectron spectroscopy (XPS) was employed to give insight into the reduction of graphene oxide (GO) using a green approach with polydopamine (PDA). In this approach, the number of carbon atoms bonded to OH and to nitrogen in PDA is considered and compared to the total intensity of the signal resulting from OH groups in polydopamine-reduced graphene oxide (PDA-GO) to show the reduction. For this purpose, GO and PDA-GO with different times of reduction were prepared and characterized by Raman Spectroscopy and XPS. The PDA layer was removed to prepare reduced graphene oxide (RGO) and the effect of all chemical treatments on the thermal and electrical properties of the materials was studied. The results show that the complete reduction of the OH groups in GO occurred after 180 min of reaction. It was also concluded that Raman spectroscopy is not well suited to determine if the reduction and restoration of the sp2 structure occurred. Moreover, a significant change in the thermal stability was not observed with the chemical treatments. Finally, the electrical powder conductivity decreased after reduction with PDA, increasing again after its removal.

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