scholarly journals Green Solid-State Chemical Reduction of Graphene Oxide Supported on a Paper Substrate

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 693
Author(s):  
Angela Longo ◽  
Mariano Palomba ◽  
Gianfranco Carotenuto
Keyword(s):  
Graphene Oxide ◽  
Solid State ◽  
Chemical Reduction ◽  
Low Cost ◽  
Reduction Process ◽  
Thermal Reduction ◽  
Conversion Degree ◽  
Reduction Techniques ◽  
Reduction Methods ◽  
State Chemical

The reduction of graphene oxide (GO) thin films deposited on substrates is crucial to achieve a technologically useful supported graphene material. However, the well-known thermal reduction process cannot be used with thermally unstable substrates (e.g., plastics and paper), in addition photo-reduction methods are expensive and only capable of reducing the external surface. Therefore, solid-state chemical reduction techniques could become a convenient approach for the full thickness reduction of the GO layers supported on thermally unstable substrates. Here, a novel experimental procedure for quantitative reduction of GO films on paper by a green and low-cost chemical reductant (L-ascorbic acid, L-aa) is proposed. The possibility to have an effective mass transport of the reductant inside the swelled GO solid (gel-phase) deposit was ensured by spraying a reductant solution on the GO film and allowing it to reflux in a closed microenvironment at 50 °C. The GO conversion degree to reduced graphene oxide (r-GO) was evaluated by Fourier transform infrared spectroscopy (FT-IR) in attenuated total reflectance (ATR) mode and X-ray Diffraction (XRD). In addition, morphology and wettability of GO deposits, before and after reduction, were confirmed by digital USB microscopy, scanning electron microscopy (SEM), and contact angle measurements. According to these structural characterizations, the proposed method allows a bulky reduction of the coating but leaves to a GO layer at the interface, that is essential for a good coating-substrate adhesion and this special characteristic is useful for industrial exploitation of the material.

The Effect of Different Reduction Methods on Conductivity of Reduced-Graphene Oxide (r-GO)

2015 ◽  
Vol 815 ◽  
pp. 216-220 ◽  
Author(s):  
Muhammad Mahyiddin Ramli ◽  
K.N. Hanim ◽  
M.R. Muda ◽  
Siti Salwa Mat Isa ◽  
M.F. Jamlos
Keyword(s):  
Hydrogen Peroxide ◽  
Graphene Oxide ◽  
Thermal Treatment ◽  
Reduced Graphene Oxide ◽  
Electrical Resistance ◽  
Chemical Reduction ◽  
Thermal Reduction ◽  
Reduced Graphene ◽  
Reduction Methods ◽  
Chemically Reduced Graphene Oxide

Large quantity of graphene oxide (GO) was prepared by Modified Hummer’s method, in which graphite was treated with a mixture of sulphuric acid, potassium permanganate and hydrogen peroxide. A chemically reduced graphene oxide (r-GO) was prepared using sodium borohydride (NaBH4), followed by thermal treatment and thermal treatment of chemically reduce using NaBH4. The electrical resistance of r-GO was measured using Keithley sourcemeter. The results revealed that r-GO show lower resistance on thermal reduction which is 2.39 kΩ compared to chemical reduction and thermal of NaBH4reduction which is 2.18 MΩ and 3.16 kΩ respectively. It can be concluded that thermal reduction is the best method to produce high conductivity r-GO film.

X-Ray Diffraction Evaluation of the Average Number of Layers in Thermal Reduced Graphene Powder for Supercapacitor Nanomaterial

2019 ◽  
Vol 958 ◽  
pp. 117-122 ◽  
Author(s):  
Quezia de Aguiar Cardoso ◽  
Julio César Serafim Casini ◽  
Luzinete Pereira Barbosa ◽  
Marilene Morelli Serna ◽  
Eguiberto Galego ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Thermal Treatment ◽  
Low Cost ◽  
Reduction Process ◽  
Thermal Reduction ◽  
Processing Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Graphene Layers ◽  
Number Of Layers

Graphene oxide (GO) can be partially reduced to graphene-like sheets by removing the oxygen-containing groups and recovering the conjugated structure. In this work, the thermal reduction of GO powder has been carried out using back pumping vacuum pressures and investigated employing X-ray diffraction analysis. The experimental results of estimating the number of graphene layers on the reduced powder at various temperatures (200 – 1000 °C) have been reported. Electrical changes have been produced in a graphene oxide with the vacuum reduction process. This study has shown that the ideal processing temperature for reducing graphene oxide nanomaterial was about 400 °C. It has also been shown that at 600 °C the number of layers in the reduced nanomaterial increased. The internal series equivalent resistance (ESR) has been improved substantially with the vacuum thermal treatment even at temperatures above 400 °C. ESR was reduced from 95.0 to about 13.8 Ω cm2 with this processing. These results showed that the process can be applied to the reduction of graphene oxide to produce supercapacitor nanomaterials. The advantage of employing this method is that the processing is a straightforward and low cost thermal treatment that might be used for large amount of nanocomposite material.

scholarly journals Facile Synthesis of Carboxymethyl Cellulose Coated Core/Shell SiO2@Cu Nanoparticles and Their Antifungal Activity against Phytophthora capsici

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 888
Author(s):  
Nguyen Thi Thanh Hai ◽  
Nguyen Duc Cuong ◽  
Nguyen Tran Quyen ◽  
Nguyen Quoc Hien ◽  
Tran Thi Dieu Hien ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Carboxymethyl Cellulose ◽  
Chemical Reduction ◽  
Low Cost ◽  
Phytophthora Capsici ◽  
Reduction Process ◽  
Spherical Shape ◽  
Core Shell ◽  
Cu Nanoparticles ◽  
Average Size

Cu nanoparticles are a potential material for creating novel alternative antimicrobial products due to their unique antibacterial/antifungal properties, stability, dispersion, low cost and abundance as well as being economical and ecofriendly. In this work, carboxymethyl cellulose coated core/shell SiO2@Cu nanoparticles (NPs) were synthesized by a simple and effective chemical reduction process. The initial SiO2 NPs, which were prepared from rice husk ash, were coated by a copper ultrathin film using hydrazine and carboxymethyl cellulose (CMC) as reducing agent and stable agent, respectively. The core/shell SiO2@Cu nanoparticles with an average size of ~19 nm were surrounded by CMC. The results indicated that the SiO2@Cu@CMC suspension was a homogenous morphology with a spherical shape, regular dispersion and good stability. Furthermore, the multicomponent SiO2@Cu@CMC NPs showed good antifungal activity against Phytophthora capsici (P. capsici). The novel Cu NPs-based multicomponent suspension is a key compound in the development of new fungicides for the control of the Phytophthora disease.

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.

Growth of Ag Nanoparticles by Spin Coating

2013 ◽  
Vol 24 ◽  
pp. 163-167 ◽  
Author(s):  
S.D. Sartale ◽  
A.A. Ansari
Keyword(s):  
Ag Nanoparticles ◽  
Spin Coating ◽  
Chemical Reduction ◽  
Reduction Process ◽  
Thermal Reduction ◽  
Environment Effects ◽  
Uv Visible ◽  
Absorbance Spectra ◽  
Scanning Electron ◽  
Better Than

Ag nanoparticles were grown on glass substrate by spin coating of Ag ions (AgNO3) solution followed by either chemical reduction, in aqueous hydrazine or NaBH4 solution, or by thermal reduction in H2 environment. Effects of different reducing agent have been explained. Morphology and absorbance spectra ofAg nanoparticles films, measured by using Scanning Electron Microscopy (SEM) and UV-visible Spectrophotometer techniques, are used to understand effect of reduction process on growth of Ag nanoparticles. To grow uniformly size distributed Ag nanoparticles thermal reduction in H2 is better than chemical reduction by aqueous either NaBH4 orhydrazine hydrate solutions.

The Preparation of Graphene via Thermal Reduction Method

2012 ◽  
Vol 557-559 ◽  
pp. 1539-1542
Author(s):  
Jian Fang Wang ◽  
Ya Nan Lv ◽  
Yin Long ◽  
Cheng An Tao ◽  
Hui Zhu
Keyword(s):  
Graphene Oxide ◽  
High Temperature ◽  
Smooth Surface ◽  
Reduction Method ◽  
Thermal Reduction ◽  
Thermal Reaction ◽  
Thermal Method ◽  
High Quality ◽  
Graphene Surface ◽  
Reduction Methods

In this paper, the graphene oxide reducing by photochemical-thermal reduction and high-temperature thermal reduction was studied to get qualified graphene and avoid the re-aggregation. The results show that graphene obtained by both of the two reduction methods all maintained the original well-layered morphology of the graphene oxide. The graphene had smooth surface and high quality as completely reduced by high-temperature thermal method. However, the reduction the photochemical-thermal reaction was not sufficient and caused many vesicles on the graphene surface due to the low temperature and the lack of reaction time.

scholarly journals A solid-state chemical method for synthesizing MgO nanoparticles with superior adsorption properties

RSC Advances ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 2011-2017 ◽  
Author(s):  
Hongyu Zhang ◽  
Jindou Hu ◽  
Jing Xie ◽  
Shiqiang Wang ◽  
Yali Cao
Keyword(s):  
Wastewater Treatment ◽  
Solid State ◽  
Chemical Method ◽  
Low Cost ◽  
Adsorption Properties ◽  
Mgo Nanoparticles ◽  
State Chemical

As a traditional and effective adsorbent, MgO is a low-cost, eco-friendly, nontoxic, and economical material for wastewater treatment.

scholarly journals Caffeine as Nitrogen Source for Reduce Graphene Doping, and Its Functionalization with Silver Nanowires

2018 ◽  
Author(s):  
Daniel Ramirez-Gonzalez ◽  
Jose de Jesus Cruz-Rivera ◽  
Hugo Tiznado ◽  
Angel Gabriel Rodriguez-Vazquez ◽  
Ivan Guillen-Escamilla ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Nitrogen Source ◽  
Silver Nanowires ◽  
Chemical Reduction ◽  
Low Cost ◽  
Nitrogen Doped ◽  
Nanowires Growth ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene ◽  
Ft Ir

In this work, we propose an easy and a low cost method for the synthesis of Nitrogen-Doped Graphene NDG and its silver nanowires NW functionalization NWGN. The synthesis was performed using the improved graphene oxide method, chemical reduction of graphene oxide in the presence of caffeine as green nitrogen source and the subsequently the silver nanowires growth in the surface, by the chemical reductions salts in the presence of NG. Achieving a homogeneous growing (coating) of graphene sheets. The samples were analyzed using conventional characterization techniques: SEM-EDX, XRD, FT-IR, RAMAN, TEM, HRTEM, STEM and XPS.

A facile and versatile method for preparation of colored TiO2 with enhanced solar-driven photocatalytic activity

Nanoscale ◽  
2014 ◽  
Vol 6 (17) ◽  
pp. 10216-10223 ◽  
Author(s):  
Huaqiao Tan ◽  
Zhao Zhao ◽  
Mang Niu ◽  
Chengyu Mao ◽  
Dapeng Cao ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Solid State ◽  
Large Scale ◽  
Chemical Reduction ◽  
Photocatalytic Properties ◽  
Scale Production ◽  
Large Scale Production ◽  
State Chemical ◽  
Reduction Approach

A simple and facile solid-state chemical reduction approach for a large-scale production of colored TiO2 with good photocatalytic properties was developed.

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