scholarly journals Micro Scalable Graphene Oxide Productions Using Controlled Parameters in Bench Reactor

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1975
Author(s):  
Carolina S. Andrade ◽  
Anna Paula S. Godoy ◽  
Marcos Antonio Gimenes Benega ◽  
Ricardo J. E. Andrade ◽  
Rafael Cardoso Andrade ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Scale Up ◽  
Physicochemical Characteristics ◽  
Structural Quality ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Process Reproducibility

The detailed study of graphene oxide (GO) synthesis by changing the graphite/oxidizing reagents mass ratios (mG/mROxi), provided GO nanosheets production with good yield, structural quality, and process savings. Three initial samples containing different amounts of graphite (3.0 g, 4.5 g, and 6.0 g) were produced using a bench reactor under strictly controlled conditions to guarantee the process reproducibility. The produced samples were analyzed by Raman spectroscopy, atomic force microscopy (AFM), x-ray diffraction (XDR), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR) and thermogravimetry (TGA) techniques. The results showed that the major GO product comprised of nanosheets containing between 1–5 layers, with lateral size up to 1.8 µm with high structural quality. Therefore, it was possible to produce different batches of graphene oxide with desirable physicochemical characteristics, keeping the amount of oxidizing reagent unchanged. The use of different proportions (mG/mROxi) is an important strategy that provides to produce GO nanostructures with high structural quality and scale-up, which can be well adapted in medium-sized bench reactor.

Characterization of X-ray irradiated graphene oxide coatings using X-ray diffraction, X-ray photoelectron spectroscopy, and atomic force microscopy

2013 ◽  
Vol 28 (2) ◽  
pp. 68-71 ◽  
Author(s):  
Thomas N. Blanton ◽  
Debasis Majumdar
Keyword(s):  
Atomic Force Microscopy ◽  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
High Energy ◽  
X Ray Diffraction ◽  
Carbon Phase ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After

In an effort to study an alternative approach to make graphene from graphene oxide (GO), exposure of GO to high-energy X-ray radiation has been performed. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM) have been used to characterize GO before and after irradiation. Results indicate that GO exposed to high-energy radiation is converted to an amorphous carbon phase that is conductive.

scholarly journals A Review on Common Methods for Characterizing Graphene Oxide (GO)

2019 ◽  
pp. 1-8
Author(s):  
Md. Shafiul Islam
Keyword(s):  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Chemical Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
The Past ◽  
Atomic Force ◽  
Scientific World ◽  
Uv Visible

Graphene oxide, two-dimensional material with the thickness of 1.1±0.2 nm, has gained attention to a greater extent in the field of science for its radically distinctive properties: physical, chemical, optical as well as electrical etc. Graphene oxide (monolayer sheet) has been synthesized by oxidizing graphite (millions of layer) to graphite oxide (multilayers) which has been converted into graphene oxide via exfoliation followed by sonication and centrifugation - a method mentioned as Modified Hummer Method. I focus on the chemical structure of graphene oxide. However, I discuss the different analytical methods such as UV-Visible spectroscopy, Atomic Force Microscopy (AFM), X-ray Photoelectron Spectroscopy (XPS), Fourier Transform Infrared Spectroscopy (FTIR) as well as X-ray Diffraction pattern for characterizing the graphene oxide. Furthermore, this review covers the analytical evaluation of graphene oxide and discuss the past, present and future of graphene oxide in the scientific world.

Investigation of the Effect of Uv-Assisted Oxidation and Nitridation of Hafnium Metal Films

2003 ◽  
Vol 780 ◽  
Author(s):  
C. Essary ◽  
V. Craciun ◽  
J. M. Howard ◽  
R. K. Singh
Keyword(s):  
Uv Radiation ◽  
Photoelectron Spectroscopy ◽  
Grazing Angle ◽  
X Ray Diffraction ◽  
Metal Thin Films ◽  
X Ray ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Silicon Interface

AbstractHf metal thin films were deposited on Si substrates using a pulsed laser deposition technique in vacuum and in ammonia ambients. The films were then oxidized at 400 °C in 300 Torr of O2. Half the samples were oxidized in the presence of ultraviolet (UV) radiation from a Hg lamp array. X-ray photoelectron spectroscopy, atomic force microscopy, and grazing angle X-ray diffraction were used to compare the crystallinity, roughness, and composition of the films. It has been found that UV radiation causes roughening of the films and also promotes crystallization at lower temperatures.Furthermore, increased silicon oxidation at the interface was noted with the UVirradiated samples and was shown to be in the form of a mixed layer using angle-resolved X-ray photoelectron spectroscopy. Incorporation of nitrogen into the film reduces the oxidation of the silicon interface.

Improved Functional Capabilities of Quasi-Two-Dimensional Tungsten Oxide Nanostructures

2016 ◽  
Vol 689 ◽  
pp. 55-59
Author(s):  
Serge Zhuiykov
Keyword(s):  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Current Sensing ◽  
X Ray ◽  
Force Microscopy ◽  
Functional Capabilities ◽  
Atomic Force ◽  
Oxide Nanostructures ◽  
Afm Analysis

Electrical properties and morphology of orthorhombic β–WO3 nano-flakes with thickness of ~7-9 nm were investigated at the nanoscale using energy dispersive X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and current sensing force spectroscopy atomic force microscopy (CSFS-AFM, or PeakForce TUNATM). CSFS-AFM analysis established good correlation between the topography of the developed nanostructures and various features of WO3 nano-flakes synthesized via a two-step sol-gel-exfoliation method. It was determined that β–WO3 nano-flakes annealed at 550°C possess distinguished and exceptional thickness-dependent properties in comparison with the bulk, micro- and nano-structured WO3 synthesized at alternative temperatures.

STUDIES ON SURFACE STRUCTURE, MORPHOLOGY AND COMPOSITION OF Co–W COATINGS ELECTRODEPOSITED WITH DIRECT AND PULSE CURRENT USING GLUCONATE BATH

2013 ◽  
Vol 20 (01) ◽  
pp. 1350006 ◽  
Author(s):  
PARTHASARATHI BERA ◽  
H. SEENIVASAN ◽  
K. S. RAJAM
Keyword(s):  
Photoelectron Spectroscopy ◽  
Pulse Current ◽  
Diffraction Field ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Force Microscopy ◽  
Dsc Studies ◽  
Atomic Force ◽  
Electrodeposited Coating

Co–W alloy coatings were deposited with direct current (DC) and pulse current (PC) electrodeposition methods using gluconate bath at pH5 and characterized by X-ray diffraction, field emission scanning electron microscopy, atomic force microscopy, differential scanning calorimetry (DSC) and X-ray photoelectron spectroscopy (XPS). DSC studies hint at the possibility of formation of metallic glasses. Detailed XPS studies of these alloy coatings have been carried out to compare elemental states and composition of Co and W in DC and PC electrodeposited alloys. DC-plated alloy has significant amount of Co and W metal along with their respective oxidized species. In contrast, mainly oxidized metals are present in the following layers of as-deposited coatings prepared with PC plating. Concentration of Co metal is observed to increase during sputtering, whereas there is no change in W6+ concentration. Microhardness measurement of all the Co–W coatings shows higher hardness compared to Co metal and 1:1 and 1:4 PC electrodeposited coatings show little higher hardness compared to 1:2 PC electrodeposited coating.

scholarly journals Electronic and vibrational decoupling in chemically exfoliated bilayer 2D-V2O5

2021 ◽  
Author(s):  
Reshma P R ◽  
Anees Pazhedath ◽  
Ganesan Karuppiah ◽  
Arun Prasad ◽  
Sandip Dhara
Keyword(s):  
Transition Metal ◽  
Photoelectron Spectroscopy ◽  
Density Functional ◽  
Blue Shift ◽  
X Ray Diffraction ◽  
Phonon Modes ◽  
Visible Absorption ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force

Abstract Recently emerged transition metal oxide (TMO) based 2D nanostructures are gaining a foothold in advanced applications. Unlike, 2D transition metal dichalchogenides, it is strenuous to obtain high quality thin TMOs due to exotic surface reconstruction during synthesis. Herein, we report the synthesis of bilayer thin 2D-V2O5 nanosheets using chemical exfoliation. Synchrotron X-ray diffraction, X-ray photoelectron spectroscopy and atomic force microscopy substantiate the successful formation of bilayer thin 2D-V2O5. Ultraviolet-visible absorption spectra exhibit a thickness dependent blue shift in the optical band gap, signifying the emergence of electronic decoupling. Raman spectroscopy fingerprinting shows a thickness dependent vibrational decoupling of phonon modes. Further, it has been verified by computing the lattice vibrational modes using density functional perturbation theory. In this study, the manifestation of the electronic and vibrational decoupling is used as a novel probe to confirm the successful exfoliation of bilayer 2D-V2O5 from its bulk counterpart.

scholarly journals Ultrashort Pulsed Laser Ablation of Magnesium Diboride: Plasma Characterization and Thin Films Deposition

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Angela De Bonis ◽  
Agostino Galasso ◽  
Antonio Santagata ◽  
Roberto Teghil
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Optical Emission ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
Laser Target ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron

A MgB2target has been ablated by Nd:glass laser with a pulse duration of 250 fs. The plasma produced by the laser-target interaction, showing two temporal separated emissions, has been characterized by time and space resolved optical emission spectroscopy and ICCD fast imaging. The films, deposited on silicon substrates and formed by the coalescence of particles with nanometric size, have been analyzed by scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, micro-Raman spectroscopy, and X-ray diffraction. The first steps of the films growth have been studied by Transmission Electron Microscopy. The films deposition has been studied by varying the substrate temperature from 25 to 500°C and the best results have been obtained at room temperature.

scholarly journals Formation of Size and Density Controlled Nanostructures by Galvanic Displacement

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 644
Author(s):  
Minh Tran ◽  
Sougata Roy ◽  
Steven Kmiec ◽  
Alison Whale ◽  
Steve Martin ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Uniform Density ◽  
X Ray Diffraction ◽  
Galvanic Displacement ◽  
X Ray ◽  
Raman Spectroscopic ◽  
Force Microscopy ◽  
Atomic Force ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

Gold (Au) and copper (Cu)-based nanostructures are of great interest due to their applicability in various areas including catalysis, sensing and optoelectronics. Nanostructures synthesized by the galvanic displacement method often lead to non-uniform density and poor size distribution. Here, density and size-controlled synthesis of Au and Cu-based nanostructures was made possible by galvanic displacement with limited exposure to hydrofluoric (HF) acid and the use of surfactants like L-cysteine (L-Cys) and cetyltrimethylammonium bromide (CTAB). An approach involving cyclic exposure to HF acid regulated the nanostructure density. Further, the use of surfactants generated monodisperse nanoparticles in the initial stages of the deposition with increased density. The characterization of Au and Cu-based nanostructures was performed by scanning electron microscopy, atomic force microscopy, UV-Visible spectroscopy, X-ray photoelectron spectroscopy, Raman spectroscopy and X-ray diffraction. The surface enhanced Raman spectroscopic measurements demonstrated an increase in the Raman intensity by two to three orders of magnitude for analyte molecules like Rhodamine 6G dye and paraoxon.

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