Microwave-Aided Exfoliation and Reduction of Graphene Oxide

2021 ◽  
Vol 21 (3) ◽  
pp. 1667-1671
Author(s):  
Sonal Rattan ◽  
Suresh Kumar ◽  
J. K. Goswamy
Keyword(s):  
Graphene Oxide ◽  
Microwave Treatment ◽  
Chemical Oxidation ◽  
Spectroscopic Techniques ◽  
X Ray Diffraction ◽  
Layer Spacing ◽  
Raman Spectroscopic ◽  
Morphological Studies ◽  
Efficient Reduction ◽  
Reduced Graphene

Wet chemical oxidation methods have been widely used to prepare graphene oxide from graphite flakes, which in turn can be reduced using strong and hazardous chemicals like hydrazine. In this report, we have demonstrated a non-hazardous method for simultaneous exfoliation and reduction of graphene oxide. Fourier transformed infrared (FTIR), UV-Visible, X-ray diffraction and Raman spectroscopic techniques have been used to ascertain chemical functionalization and reduction of graphene oxide. Morphological studies were carried out using field emission scanning electron microscopy. Morphological details of the microwave reduced graphene showed enhancement in inter-layer spacing of graphene sheets after microwave treatment. The enhancement in electrical conductivity of graphene oxide after microwave treatment indicates its efficient reduction.

scholarly journals Magnetization of Ultraviolet-Reduced Graphene Oxide Flakes in Composites Based on Polystyrene

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2519
Author(s):  
Alexander N. Ionov ◽  
Mikhail P. Volkov ◽  
Marianna N. Nikolaeva ◽  
Ruslan Y. Smyslov ◽  
Alexander N. Bugrov
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Reduction Process ◽  
X Ray Diffraction ◽  
Mesoscopic Structure ◽  
Reduced Graphene ◽  
Study Results ◽  
Edge Defects ◽  
Mesoscopic Level ◽  
Ferromagnetic Hysteresis

This work presents our study results of the magnetization of multilayer UV-reduced graphene oxide (UV-rGO), polymer matrix (polystyrene), and a conjugated composite based on them. The mesoscopic structure of the composites synthesized in this work was studied by such methods as X-ray diffraction, SEM, as well as NMR-, IR- and Raman spectroscopy. The magnetization of the composites under investigation and their components was measured using a vibrating-sample magnetometer. It has been shown that the UV-reduction process leads to the formation of many submicron holes distributed inside rGO flakes, which can create edge defects, causing possibly magnetic order in the graphite samples under investigation on the mesoscopic level. This article provides an alternative explanation for the ferromagnetic hysteresis loop in UV-rGO on the base of superconductivity type-II.

Thermal reduction to control the spacing in graphene oxide membranes: effect on ion diffusion and electrical conduction

RSC Advances ◽  
2016 ◽  
Vol 6 (74) ◽  
pp. 70012-70017 ◽  
Author(s):  
A. Alhadhrami ◽  
S. Salgado ◽  
V. Maheshwari
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Electrical Conduction ◽  
Thermal Reduction ◽  
Electrochemical Characteristics ◽  
Ion Diffusion ◽  
Layer Spacing ◽  
Reduced Graphene ◽  
Oxide Membranes ◽  
Graphene Oxide Membranes

Inter-layer spacing in reduced graphene-oxide membranes which modulates their ion-diffusion electrical and electrochemical characteristics is controlled by temperature of thermal reduction.

scholarly journals Poly(3,4-ethylenedioxythiophene)-reduced graphene oxide/copper-based metal-organic frameworks as a high-performance symmetrical supercapacitor device

2021 ◽  
Author(s):  
Dharshini Mohanadas ◽  
Muhammad Amirul Aizat Mohd Abdah ◽  
Nur Hawa Nabilah Azman ◽  
Thahira B.S.A. Ravoof ◽  
Yusran Sulaiman
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
High Performance ◽  
Metal Organic Framework ◽  
Specific Power ◽  
X Ray Diffraction ◽  
Reduced Graphene ◽  
Metal Organic ◽  
Energy Storage Material ◽  
Organic Framework

Abstract A novel poly(3,4-ethylenedioxythiophene)-reduced graphene oxide/copper-based metal-organic framework (PrGO/HKUST-1) has been successfully fabricated by incorporating electrochemically synthesized poly(3,4-ethylenedioxythiophene)-reduced graphene oxide (PrGO) and hydrothermally synthesized copper-based metal-organic framework (HKUST-1). The field emission scanning microscopy (FESEM) and elemental mapping analysis revealed an even distribution of poly(3,4-ethylenedioxythiophene) (PEDOT), reduced graphene oxide (rGO) and HKUST-1. The crystalline structure and vibration modes of PrGO/HKUST-1 was validated utilizing X-ray diffraction (XRD) as well as Raman spectroscopy, respectively. A remarkable specific capacitance (360.5 F/g) was obtained for PrGO/HKUST-1 compared to HKUST-1 (103.1 F/g), PrGO (98.5 F/g) and PEDOT (50.8 F/g) using KCl/PVA as a gel electrolyte. Moreover, PrGO/HKUST-1 composite with the longest charge/discharge time displayed excellent specific energy (21.0 Wh/kg), specific power (479.7 W/kg) and outstanding cycle life (95.5%) over 4000 cycles. Thus, the PrGO/HKUST-1 can be recognized as a promising energy storage material.

scholarly journals Synthesis, Structural and Optical Investigations of (Pb, Bi)TiO3 Borosilicate Glasses

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Chandkiram Gautam
Keyword(s):  
Spectroscopic Techniques ◽  
Borosilicate Glasses ◽  
X Ray Diffraction ◽  
Raman Spectroscopic ◽  
Spectral Bands ◽  
Prepared Glass ◽  
Infrared And Raman Spectroscopy ◽  
Uv Visible ◽  
Diffraction Patterns ◽  
Spectral Patterns

A new series of lead bismuth titanate borosilicate glasses with addition of one percent lanthanum oxide have been synthesized using melt-quench technique. X-ray diffraction patterns have been recorded to confirm the amorphous nature of the prepared glass samples. The synthesized glasses have been characterized by using various spectroscopic techniques such as UV-visible, infrared, and Raman spectroscopy. UV-visible measurements were recorded in the wavelength range from 200 to 1100 nm whereas IR and Raman spectroscopic measurements were recorded over a continuous wavenumber range from 400 to 5000 cm−1 and 1000 to 2000 cm−1 respectively. The different absorption peaks/bands were formed in IR spectral patterns. The spectral bands appear towards the lower wavenumber sides due to the Bi and Pb, content while the bands appear towards the higher wavenumber sides due to the formation of diborate and triborate network units.

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.

Study on Magnetic Properties of Na-Doped rGO Prepared from Coconut Shells

2020 ◽  
Vol 855 ◽  
pp. 160-165
Author(s):  
Deril Ristiani ◽  
Niken Sylvia Puspitasari ◽  
Retno Asih ◽  
Fahmi Astuti ◽  
Malik Anjelh Baqiya ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Mixing Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reduced Graphene ◽  
Naoh Solution ◽  
Na Ions ◽  
Diffraction Peaks ◽  
Coconut Shells

Na-doped reduced graphene oxide (Na-rGO) was prepared by wet mixing process of the reduced graphene oxide (rGO) in NaOH solution. The results showed that the rGO doped with Na ions can increase its magnetization approximately 2 times greater than that in rGO without doping. Saturation magnetization (Ms) for rGO and Na-rGO samples are 0.017 emu/g and 0.037 emu/g, respectively. The increasing value of magnetization is suggested to be due to defect presented in the Na-rGO samples. Both samples, rGO and Na-rGO, have the similar XRD (X-ray Diffraction) spectra that is marked by two characteristic diffraction peaks of rGO, which are associated with [002] and [10] planes, followed by the increasing inter-planar distance in Na-rGO samples which might be due to Na ions intercalation into rGO sheets, confirmed by the energy-dispersive X-ray (EDX) result revealing the presence of Na atoms in rGO.

scholarly journals X-ray diffraction investigations of nanostructured ZnO coated with reduced graphene oxide.

2019 ◽  
Vol 1292 ◽  
pp. 012011 ◽  
Author(s):  
I Boukhoubza ◽  
M Khenfouch ◽  
M Achehboune ◽  
B M Mothudi ◽  
I Zorkani ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reduced Graphene

scholarly journals Preparation, characterization and photocatalytic activity of Co3O4/LiNbO3 composite

2013 ◽  
Vol 11 (6) ◽  
pp. 920-926 ◽  
Author(s):  
Beata Zielinska ◽  
Magdalena Janus ◽  
Ryszard Kalenczuk
Keyword(s):  
Photocatalytic Activity ◽  
Hydrogen Generation ◽  
Cobalt Content ◽  
Cobalt Nitrate ◽  
Spectroscopic Techniques ◽  
X Ray Diffraction ◽  
X Ray ◽  
Raman Spectroscopic ◽  
Photocatalytic Hydrogen Generation ◽  
Content Range

AbstractThe Co3O4/LiNbO3 composites were synthesized by impregnation of LiNbO3 in an aqueous solution of cobalt nitrate and next by calcination at 400°C. The activity of produced samples has been investigated in the reaction of photocatalytic hydrogen generation. The crystallographic phases, optical and vibronic properties were studied using X-ray diffraction (XRD), diffuse reflectance (DR) UV-vis and resonance Raman spectroscopic techniques, respectively. The influence of cobalt content (range from 0.5 wt.% to 4 wt.%) on the photocatalytic activity of Co3O4/LiNbO3 composites for photocatalytic hydrogen generation has been investigated. Co3O4/LiNbO3 composites exhibited higher than LiNbO3 photocatalytic activity for hydrogen generation. The highest H2 evolution efficiency was observed for Co3O4/LiNbO3 composite with 3 wt.% cobalt content. The amount of H2 obtained in the presence of LiNbO3 and Co3O4/LiNbO3 (3 wt.% of cobalt content) was 1.38 µmol/min and 2.59 µmol min−1, respectively.

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