Graphene - Science topic

I am planning to electrospun a water-soluble polymer with rGO.

I would like to learn the details coding GFET through SILVACO but need reference. Hoping anyone could help me

A single layer of carbon atoms arranged in such a honeycomb structure forms a single graphene sheet. Several sheets stacked one on top of the other are regarded as multi-layer graphene, up to the point where the material becomes graphite (usually over about 30 layers, although clear standardization is severely lacking at the moment). Graphite, a 3D crystal composed of weakly coupled graphene layers, is a relatively common material - used in pencil tips, batteries and many more. In graphene, each carbon atom is covalently bonded to three other carbon atoms. Thanks to the strength of the covalent bonds between carbon atoms, graphene boasts great stability and a very high tensile strength (the force in which you can stretch something before it breaks). Since graphene is flat, every atom is on the surface and is accessible from both sides, so there is more interaction with surrounding molecules. Also, the carbon atoms are bonded to only three other atoms, although they have the capability to bond to a fourth atom. This capability, combined with the aforementioned tensile strength and high surface area to volume ratio of graphene may make it appealing for use in composite materials. Graphene also enjoys electron mobility that is higher than any known material and researchers are developing methods to use this property in electronics. These futuristic properties of graphene made a future mobile oil with inclusion of gasoline products.

I would like to ask about the best conditions of sonication of graphite oxide in terms of apparatus (probe or bath), time and power in order to effectively exfoliate the graphite oxide without damaging the structure of GO sheets. The objective is to obtain water dispersion of about 5 mg/mL of the highest possible quality.

Thank you very much.

I am working to check the effect of particle size on the quality of graphene.

My suggestion is phase transfer or using a dialysis bag. Is there any way to precipitate sodium hydroxide?

Please introduce an article or journal about the application of elemental two-dimensional nanoparticles in dentistry.. Two-dimensional nanomaterials such as graphene, silicene, etc.

I established a model of Ca decorated graphene 2D material with c lattice constant 20A, and wanted to do hydrogen molecular adsorption, the process is like this

1 Optimize the graphene system structure under Ca decorated.

2 throw in two hydrogen atoms at a distance of 0.7A for molecular dynamics analysis.

But in the analysis I found that the two hydrogen atoms separated, and flow upward, and did not be adsorbed, is this right?.

Because When I set one hydrogen atom, it got adsorbed very quickly.

or how can i draw it

I need the particle size and the shape of graphene oxide in epoxy powder as shown in the following FESEM morphology

How do I prepare different concentrations of graphene oxide (1, 5, 10ug/ml) for MIC from the powered form of synthesized GO? Please explain the steps.

Common parameters would be 200C for 8 hours for activated carbon/biochar. How about graphene oxide? Does it differ?

Recently i read about CNT/graphene Hybrid and there are few variants of CNT/Graphene such as (10,0) - 10h, (12,0) - 12h. What does each character means ?

Hi, I want to synthesize graphene oxide from graphite flakes for the fabrication of a graphene oxide water filtration membrane. Can you plz suggest to me the best method of synthesizing?

Also, if possible, share the protocol of graphene oxide synthesis.

Hi, I am Abdul Samad, researching graphene oxide nanomaterials. I have synthesized graphene oxide by Hammer's method, and now I want to develop a graphene oxide membrane. I have tried to develop a membrane using the vacuum filtration method, but this method didn't work. Can anyone suggest the assay, accessible, and best method of fabrication of graphene oxide water filtration membrane?

Also, can anyone suggest the best dispersion agent for graphene oxide?

I am attempting to comprehend the performance of graphene/n-type semiconductor Schottky diodes in photodetector applications.

Given that silicon (Si) and germanium (Ge) have similar electron affinities, 4.05 eV and 4 eV respectively, it might be expected that their Schottky barrier heights with graphene would be nearly identical.

However, the dark current in graphene/Ge contacts is significantly larger, as evidenced by both literature data and my experimental observations.

Beyond Schottky barrier height, what additional factors should be considered to understand this discrepancy in dark current?

Is it possible to grow graphene on the vertical wall of a structure, for example on the vertical walls of a SOI waveguide?

There are various nanostructures available for graphene such as nanosheets, nanowires, nanoribbons etc. Among them which is known for its best electrical conductivity

CNP and Dirac point in Graphene

I can access to few-layer graphene (non-oxidized) of 3-8 layers thickness and 2-8 micrometers of diameter. Is it possible to break this material into particles of 50-100 nm averaged diameter using standard laboratory equipment without altering its oxidation state?

Thank you in advance

Or in other words, what are its benefits or what distinguishes it compared to other materials? What happens when graphene is used in a waveguide? I need a detailed answer please.

Hii,

Can anyone please suggest articles for preparation of conductive ink using CNTs/graphene/ nanoparticles, etc.?

I want to get a dried, highly reduced graphene oxide from a graphene oxide solution. Is it ok to dry the solution around 80C, 24h?

Thank you.

I am prepared a Graphene solution in DMSO with different concentrations. Then I deposit the solution on a simple glass substrate, but the issue is the film is very instable in term of sticking. It is very easy to remove from the glass.

So, what the possible way to improve the adhesive of the graphene solution with glass slides. thanks

Actually I am working on Graphene oxide base metal oxides nanocomposites. When I annealed the sample under 450°C for 1 h in muffle furnace in air. The sample had changed its colour and the GO was oxidized. Please suggest me the suitable temperature and time for annealing the GO based materials. Which gas is suitable under which the annealing process should be carried?

Hi everyone,

I am trying to study Li adsorption on graphene and Electronic properties (PDOS and band structure) using Quantum Espresso. Anyone can help me how to do it? Starting from how to build the files and the steps, if there is any information, sources website can help me please let me know.

I will really appreciate it.

In the co-adsorption system of graphene oxide and oxytetracycline with soil, after the adsorption equilibrium, all of the soil and a small portion of the adsorbed graphene and oxytetracycline can be precipitated by centrifugation, but there is no good method concerning the determination of oxytetracycline and graphene oxide in the supernatant

I need to develop a PRISM(BK7) based SPR biosensor based on large area MoS2 and Graphene monolayer. To achieve my aim my requirement is in following steps.

1. First gold(Au) layer deposition (50nm thickness) on flat BK7 glass plate(Refractive Index=1.51)  We will directly apply this chip on prism hypotenuse by using suitable adhesion material with similar refractive index to glass plate.  

3. Finally transfer of Graphene monolayer (1 cm × 1 cm ×  0.345 nm ) thin film on  MoS2  monolayer.

Dear All,

We used 0.45, 1.2 and 2.5 uM filter papers for vacuum filtration for during the sythesis of graphene oxide with the Hummers method for washing of the material after final treatment with H2SO4. But each time the filter papers get clogged before long and we cannot pass almost any distilled water.

What pore size of paper do you suggest we use?

Figure: Water remaining after 2 hours of vacuum filtration on 2.5 uM filter paper

Kind regards,

Hello Im Yuliana Jiménez Gaona, and I want to shared that the user Yuliana Gaona

is taking my research and already associated with her profile ResearchGate (https://www.researchgate.net/profile/Yuliana-Gaona).

These research items are mine, please confirm the authorship to add it to my profile.

1.Tunable optical and semiconducting properties of eco-friendly-prepared reduced graphene oxide.

2.Outcome of Ivermectin in Cancer Treatment: An Experience in Loja-Ecuador

3.Deep Learning Based Computer-Aided Systems for Breast Cancer Imaging : A Critical Review.

Thanks in advance.

Cheers Yuliana Jimenez

I am working on Graphene oxide/TiO2 nanocomposites. The samples are prepared by hydrothermal method. In order to investigate the electrical properties of these semiconducting material, please suggest me to prepare samples for Hall measurement.

For modelling graphene, the CST software includes both a graphene and a graphene-Eps model. The graphene model expressed in the CST with a thickness of 0.3 nm is considered a single layer of graphene, while the graphene-EPS model is expressed as a multilayer of graphene sheets with a suitable thickness. Whenever I use the ''graphene-EPS'' model and increase the chemical potential, it does not affect any changes while using the "graphene'' model. Even at 0 eV chemical potential, it reflects all waves.Now my question is: why does it reflect all waves, even in insulting phases? I suspect that I may have made mistakes while creating the graphene material.

I want to grow graphene nanoparticles on the woven glass fiber.

Can anyone explain the possibilities of doping Zr, Ce, or any other rare metal in graphene oxide?

I prepare a 3D printed electrode for micro battery application. But it develops many cracks (shown in the image below) after drying at a very low temperature of around 35 degrees Celsius.

My ink contains active material (70%), binder (10%), carbon nanotube (10%), and Graphene oxide (10%). The solvent is either NMP or DMF, and the substrate is a Polyimide sheet.

Please suggest a way to overcome this issue.

please, can any one help me?

Currently I'm using Optimized Norm-Conserving Vanderbilt Pseudopotential from the link https://github.com/pipidog/ONCVPSP.

I'm remember this discussion in the past, and to get the correct value we need to add more orbitals to the pseudo-potential, if I remember correctly. Is there a reference that discusses this precision issue in Quantum ESPRESSO?

Is there an openly available pseudo-potential I can use to improve my data?

I had write matlab programme using kubo formula and plot the intra conductivity in the range of 1 thz to 10 thz using an article below but real part of conductivity is 3.5*10^-15 s/m is this result correct???? plz check the pdf and the figure

bcz in the article the real part of conductivity was 3.5 s/m

thank you all.

How can we numerically calculate integration like this in the picture, in which the denominator of the function becomes zero? any help will be appreciated.

This kind of integral usually appears in graphene and semi-metals. The denominator becomes zero at several points in the range of calculation, where Ω=2*ε.

I am doing experiment to grow graphene using CVD. But I found the quartz tube range (around Oven) where the yellow strains appear. I use the CH4 to synthesis the graphene under 750℃. Dear all, could you tell me what materials the yellow strains? and how can I remove it?. If possible, I can use the hydrogen plasma to remove it.

Hello.

I have some strange problem during large area CVD polycrystalline graphene transfer by using polymer(polycarbonate(PC)).

When I rinsed PC+graphene on SiO2 to remove PC, the graphene was dissolved in acetone....

I know it looks strange but some times it did not happen, many times...

Also, when I do same thing with microscale, small graphene, it never happened.

It does not look like graphene itself was dissolved in acetone.

Maybe, it was polycrystalline, large size (few mm scale).

So if I put strain on grapehen, the graphene could be removed with PC?

I changed the time and temperature of annealing process to make good contact between substrate and transferred graphen, but It did not work.

Only with Polycrystalline, large size grapehen(not just graphene. Many other semi materials also), and some time it was fine, sometimes not.

Thank you for listening.

Need detail procedure

I'm intended to incorporate sio2 (1 micron powder size) with graphene oxide and eventually have a fine and homogenous powder size of these combination.

Thanks in advance

Please click the for further information. I just want what the community thinks/feedback.

Thanks.

I am panning to make Graphene Oxide following the methodology on the paper But the comment "My reaction using the improved GO synthesis caught on fire immediately and the graphite was smouldering. You guys said slight exotherm!" on https://www.youtube.com/watch?v=sTooYDp1KD4 (explanation given by Professor James Tour himself) caught my attention. Since, I am working at a new lab, I don't want to cause any trouble while following this procedure.

Please share with me if you have faced any problems while following this procedure and also suggest me the improvisations if you have any.

Hi, I was using the Malvern Zetasizer to measure the zeta potential of GNPs in simulated cement pore solution. when I measure the zeta potential of GNPs in simulate cement pore solution, the software shows the message "Problem with cell drive circuit". In the SOPs, the materials is "Polystyrene latex", the dispersant is added manually with a dielectric constant of 5.2 (I checked in the literature, the dielectric constant is around 5.2 of simulated pore solution). But the zeta potential cannot be measured with this SOPs, and shows the message "Problem with cell drive circuit". The GNPs is conductive and the concentration is 0.02 g/L. Do you know how to measure the zeta potential of GNPs in simulated cement pore solution?

The simulated cement pore solution is saturated Ca(OH)2 with 8g/L NaOH, 22.4g/L KOH and 27.6 g/L CaSO4. PH is around 13.3

Hi,

I want to model a heterojunction using orthorhombic Bi2MoO6 slab and graphene. Since the lattice symmetry is different for both I need to make them same crystal symmetry. Therefore , I need to convert hexagonal graphene to tetragonal using vesta. Could anyone suggest the transformation matrix for the conversion?

please suggest any reference book or article related to how to construct the transformation matrix for the lattice conversion

Thank you

Recent progress in graphene research and feasibility of various graphene application in the year between 2021 to 2023

Can anyone please help to suggest if I want to take spectroscopic (uv or Fluorescence spectra ) of non-soluble powdered solids such as silica, charcoal or graphene oxide?

please provide references.

I really appreciate any help you can provide.

Hello,

What are the the best methods (in terms of time and complexity) to exfoliate graphite to synthesize graphene?

I have tried to do it using DMF as a solvent aplplying sonication followed by washing and filteration. As the XRDs of both reactant and product are typical, it did not work out well. I probably did the mistake of taking all the solid product inc graphite preciptate at the bottom while I only should have used the suspended graphene layers. I am not sure if this interpetation is accuarte enough.

Any thoughts or ideas are appreciated!!

I prepared a graphene oxide-coated granular activated carbon composite for my research. I characterized the composite using SEM and found graphene sheets on the GAC surface. However, while doing the XRD analysis, I did not get any graphene oxide peak on the XRD pattern of the composite. All the peaks I found are relevant to activated carbon. See the attached images. Could anyone please explain this phenomenon?

If we assume the tunnling effect interlayers graphene. What type of it would be either Direc tunneling or FN tunneling. If it is Direct tunnling Effect, then the electron tunnling between the interlayers can be significantly improved with bias voltage.

What suitable characterization techniques can be used to compare the activated carbon (AC) (quite graphitic in nature) and reduced graphene oxide synthesized using that AC as a precursor?

Dear professors and Scholars i have recently prepared GO... now I am washing the solution to neutralise pH can I use NaOH ? or to wash continuously using DI water? Need your comments. Thank youo.

dye-sensitized solar cell

Can anyone tell me what is the degassing temperature for the BET analysis of urea loaded with graphene oxide?

I've found that measurements made by impedance analysis, or by forming capacitors with graphene oxide plates as the dielectric layer, suggest a giant low-frequency, static polarizability or relative permittivity for this material. Can anyone help me by suggesting articles or some works relating oxidation degree to static average polarizability?

Currently, I looking for the information about the hot topic membrane modification by using graphene oxide. Because I believe that graphene oxide have a good properties and easy to modify in membrane.

Dear colleagues. I'm studying ORR on carbon materials, including graphene oxide. I'm new in this research direction and have questions: what are the compositions of the most suitable electrolytes for ORR on carbon materials? In many research papers, 0.1M KOH is presented as the most suitable one. But, acidic and neutral solutions could also be good? I need the clear understanding of the rules behind choosing the electrolyte for ORR. Any good papers, clear answers, please, share with me.

Expected Tittle:

PERFORMANCE OF FLY ASH BASED RECYCLED COARSE AGGREGATE CONCRETE WITH GRAPHENE OXIDE AS A SOLE BINDER.

Hello community,

I would like to ask for recommendations to perform experiments related to an application of nanomaterials based on graphene oxide in PAPER form containing palladium nanoparticles.

Preferably one that does not involve to much material (the more practical, the better). The main idea is to exalt the benefits of using graphene oxide in a paper like shape in comparison to the powdered form.

Thank you in advance. I would really appreciate if someone has some ideas to share as well as some related papers.

In order to use graphene oxide to improve the properties of the light block, I need cost-effective methods of graphene oxide. I am somewhat familiar with Hammer's method, but this method is both long and dangerous due to the use of concentrated acids. Please help if anyone has experience in this field.

Thank you in advance for your time.

We must prepare a molar graphene oxide solution to plot the job's plot. is there any alternative??

Thanks and Regards

Is it possible to make a molar solution of graphene oxide? If yes, How?

I could see options from companies such as Sigma Aldrich etc but I want to know which particle size etc to buy..

I shall be grateful to response from the community.

Thanks!

It will be very helpful if you guys answer with appropriate references. Thank you.

I need to know the electron mobility of monolayer graphene oxide (not reduced Graphene Oxide) if possible. I need an experimental value not the values found by modelling or simulations. If not monolayer, mobility of GO (not rGO) thin film is also appreciated. With appropriate reference of course. Thank you very much.

I have successfully synthesized both graphene and graphene oxide in solution. However, I am uncertain about the appropriate method for drying them. I am aware that freeze-drying is the most effective technique, but unfortunately, I lack access to the necessary equipment. I attempted vacuum drying at room temperature, but my pump unexpectedly malfunctioned. Now, I am considering air drying as an alternative, but I am worried it might negatively impact the quality of the materials.

Could air drying potentially lead to the undesirable re-stacking of graphene and graphene oxide layers, resulting in the formation of graphite and graphite oxide?

If you have a simulation file or an description that is related, please send it for me .thanks a lot.

Can anyone help me why using high percentages of graphene oxide can reduce electrolyte absorption and hydrophilicity in Nanofiber nanocomposite? And share an article about it?

what are differences between mechanism of heavy metal ions adsorption on activated carbon and mechanism of ion adsorption on volatege connected types of carbon electrodes?

Electrical field or functional group? Which factor really acts?

may a supercapacitor electrode without voltage absorbe ions?

Valence of ions are effective?

Recently, I looking for the information about graphene oxide (GO) especially the common problem or disadvantages when applied ion the membrane. Why GO is more special in some researchers so used as nanoparticle or catalyst in membrane modification. I am sure if every material have a weaknesses. So anyone please tell me. Give me some references to my email: [email protected]

Hello dears, I had a scientific question

I 3D printed a hydroxyapatite scaffold containing graphene oxide And then I sintered this inside the controlled atmosphere tube furnace (argon gas) at a temperature of 1350.

But some of my graphene I think is lost

This loss may be due to low gas flow?