Reduction mechanism of hydroxyl group from graphene oxide with and without –NH2 agent

2015 ◽  
Vol 477 ◽  
pp. 70-74 ◽  
Author(s):  
Mengting Jin ◽  
N. Jiao ◽  
C.X. Zhang ◽  
H.P. Xiao ◽  
K.W. Zhang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Hydroxyl Group ◽  
Reduction Mechanism

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.

Selective Reduction Mechanism of Graphene Oxide Driven by the Photon Mode versus the Thermal Mode

ACS Nano ◽  
2019 ◽  
Vol 13 (9) ◽  
pp. 10103-10112 ◽  
Author(s):  
Masaki Hada ◽  
Kiyoshi Miyata ◽  
Satoshi Ohmura ◽  
Yusuke Arashida ◽  
Kohei Ichiyanagi ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Selective Reduction ◽  
Thermal Mode ◽  
Reduction Mechanism ◽  
Photon Mode ◽  
Mode Versus

Chlorine-functionalized reduced graphene oxide for methylene blue removal

RSC Advances ◽  
2015 ◽  
Vol 5 (65) ◽  
pp. 52466-52472 ◽  
Author(s):  
Chubei Wang ◽  
Jianwei Zhou ◽  
Liangliang Chu
Keyword(s):  
Methylene Blue ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Mild Condition ◽  
Sulfuryl Chloride ◽  
Hydroxyl Group ◽  
Reduced Graphene ◽  
Methylene Blue Removal

Hydroxyl group in graphene oxide can be substituted by chlorine in sulfuryl chloride at mild condition.

scholarly journals Performances of Reduced Graphene Oxide/Iron (III) Oxide/Silica Dioxide (rGO/Fe3O4/SiO2) as a Potential Oxygen Reduction Electrocatalyst in Fuel Cell

2021 ◽  
Vol 50 (7) ◽  
pp. 2017-2024
Author(s):  
Farhanini Yusoff ◽  
Karthi Suresh
Keyword(s):  
Graphene Oxide ◽  
Oxygen Reduction ◽  
Reduced Graphene Oxide ◽  
Modified Electrode ◽  
Electrochemical Analysis ◽  
Hydroxyl Group ◽  
Current Response ◽  
Reduced Graphene ◽  
Bet Analysis ◽  
Silica Dioxide

Synthesis of the nanocomposite comprises reduced graphene oxide, iron (III) oxide and silica dioxide nanocomposites which were denoted as rGO/Fe3O4/SiO2. The acquired nanocomposite was determined to be a substitute for platinum electrode in oxygen reduction reaction (ORR) to catalyze reaction, as usage of platinum causes disadvantages in production. The nanocomposite was analyzed physically and electrochemically to ensure the quality of the synthesized compound. Fourier transform-infrared spectroscopy (FTIR) shows the presences of functional groups such as O-H hydroxyl group, C=C, C=O and existence of silica peak in the spectra of rGO/Fe3O4/SiO2, where the data is also supported by SEM-EDS. Raman Spectrophotometer shows the structural change of three different graphene related materials as modification took place and X-Ray Diffraction (XRD) analysis confirms the reduction of GO into rGO, where the crystalline structure decreased significantly approximately about 10 nm. This data supported with Brunauer-Emmett-Teller (BET) analysis through surface area examination. The compound of rGO/Fe3O4/SiO2 was drop-casted onto glassy carbon electrode (GCE) for modification into rGO/Fe3O4/SiO2/GCE to carry out electrochemical analysis where Cyclic Voltammetry (CV) shows current response by modified electrode is greater than bare GCE while Electron Impedance Spectroscopy (EIS) of same modified electrode affirms the sample underwent reversible process with stable and rapid electron transfers with minimal resistance charge transfer (RCT). The study of ORR was carried out and observed a good electrochemical response of the nanocomposite when purged with oxygen gas.

scholarly journals Simulation and Computational Study of Graphene Oxide Nanocarriers Loaded in the Absorption and Release of the Anticancer Drug of Camptothecin

2021 ◽  
Author(s):  
Omid Moradi ◽  
Leila Mahdavian
Keyword(s):  
Graphene Oxide ◽  
Folic Acid ◽  
Aqueous Medium ◽  
Lactone Ring ◽  
Computational Study ◽  
Hydroxyl Group ◽  
Cancer Drug ◽  
Drug Effectiveness ◽  
Absorption Energy ◽  
Nano Graphene

Abstract The structure of nano- graphene oxide, due to its special properties such as hydrophilicity, special surface and suitable biocompatibility, the possibility of high loading of hydrophilic and hydrophobic drugs, has attracted special attention in drug release. In this study, after simulating and optimizing the structure of nano-graphene and then nano-graphene oxide (NGO), it was used to load the anti-cancer drug of camptothecin (CA) in aqueous medium and the optimal conditions for achieving maximum loading efficiency of the drug were investigated. Due to the structure of the drug, there are two forms of lactone ring and carboxylate, which if the lactone ring form is predominant, the effectiveness of the drug is increased, which depends on the pH of environment. The calculated thermodynamic and structural results show that the solubility of the drug in relation to nano-graphene and its lactone ring state are maintained by using nano-graphene oxide. By folic acid as an intermediate in aqueous medium, the drug is released to form of lactone ring and is increased the effectiveness of drug. Lactony is maintained the drug structure and is increased the drug effectiveness. The results show that the presence of the ring in the drug structure and its binding to the mediator of folic acid to nano-graphene oxide is a stabilizing factor of keto tautomer. The calculation of vibrational frequencies show that the presence of folic acid intermediate reduces the vibrational frequency of the hydroxyl group (OH) so that its absorption energy (Ead) is equal to the lowest value 65.24 a.u.

THE BAND ENERGY ENGINEERING ON HIGH EPOXY (OR HYDROXYL) CONTENT GRAPHENE OXIDE

2019 ◽  
Vol 26 (01) ◽  
pp. 1850135 ◽  
Author(s):  
BANAFSHEH ALIZADEH ARASHLOO ◽  
MOHAMMAD TAGHI AHMADI ◽  
SAEED AFRANG
Keyword(s):  
Graphene Oxide ◽  
Energy Levels ◽  
Epoxy Group ◽  
Metal Structure ◽  
The Other ◽  
Hydroxyl Group ◽  
Bandgap Energy ◽  
Hydroxyl Groups ◽  
Adsorption Effect ◽  
Epoxy Groups

Nowadays, the superior properties of carbon-based materials especially nano structural derivation like graphene and graphene oxide (GO) spot light to the researchers. The GO has been suggested as an alternate material in device miniaturization due to its atomic structure. The memristors and nonvolatile memories are settled in these categories as a solution for the scaling limitation problem in the Moor’s law. Therefore, the GO can influence the memristor performance and characteristics. The current–voltage characteristics as the most significant parameter in the memristor design are considered. On the other hand [Formula: see text]–[Formula: see text] characteristic depends on the active layer (GO) bandgap energy in the metal/oxide/metal structure and therefore, needs to be explored. In the GO-based memristor, the bandgap energy can be changed by the percentage of the oxygen groups in comparison to the carbon on graphene sheets. Thus, the other parameters are overstated by the bandgap energy. In the presented work, the energy bandgap of a high epoxy group content of GO sheets is engineered. The opening of the bandgap in the graphene oxide by high epoxy groups content with the ratio of (O/C [Formula: see text] 50%) is studied. In other words, the oxygen adsorption effect on the Hamiltonian of the system is explored. For the proposed structure, the bandgap energy is modeled and the acceptable value (approximately equal to 2.799[Formula: see text]ev for epoxy groups) is obtained. Moreover, the hydroxyl group adsorption effect on the bandgap of the graphene oxide by high content hydroxyl group is considered (approximately equal to 2.647[Formula: see text]ev for epoxy groups). Consequently, the different absorption energy effects on the bandgap of the GO is participated and the opening bandgap in the range of 2[Formula: see text]ev to 3[Formula: see text]ev is obtained. The excitonic effect on the suggested model by epoxy groups and hydroxyl groups is explored and it is realized that the energy levels in the Dirac points of epoxy groups are closer than those of the hydroxyl groups.

Electrical and spectroscopic investigations on the reduction mechanism of graphene oxide

Carbon ◽  
2013 ◽  
Vol 55 ◽  
pp. 126-132 ◽  
Author(s):  
Seiji Obata ◽  
Hiroshige Tanaka ◽  
Koichiro Saiki
Keyword(s):  
Graphene Oxide ◽  
Reduction Mechanism ◽  
Spectroscopic Investigations
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