Synthesis of Graphene Oxide by the modified Hummer's method used in the GESMAT group. 

Well, Mn would induce other effects, such as catalytic Activity, so depends

@@cigmmad I am going to try using it in electrochemistry, primarily for enhancing anodes in batteries in experiments. I wonder if there is any other way of getting rid of Mn.

After we got the GO solution, we put the solution in the centrifugue tubes, as.many as they fit in the centrífugue machine (6 in our case). We centrífugue, remove the supernatant, add HCl 5%, shake to resuspend some 2 min, centrífugue, and repeat three times with 5% HCl and other 3 with DI H2O. In the latest wash we recover powder with some remaining water in a porcelain capsule to dry in the oven at 60oC by 24 hr ñ.

@@rosaliaimroatulmufidah7450 hello, yes, it is normal. The washings with DI water after HCl are intended to remove Cl ions. But pH of a GO suspensión is around 3-5, normally. Best regards

Three Volumes. Some 150 ml each one.

Yes, is the right color. Congrats!

Hi, the one you mention Is calles Marcano Method. We havent tried it to avoid using H3PO4 (very corrosive), but they are reports for good quality GO. Our method leds to good repeteability, good oxidation degree, very good dispersability in water, high exfoliation degree.

Fast addition or KMnO4 during oxidation or if H2O2 and water at ehe end may reduce GO and turn black the suspension

As someone commented that it got fumes out in laboratory.

Because if you add it fast the reaction Will be fast and GO will became reduced

@@cigmmad we should add it in when flask in ice bath or in room temperature water (35°c )?

Yes but it will be hard to avoid boiling and evaporation. You Will have to be adding extra water

Enough to do an homogenous mixture. Nevertheless, this time shall influence the final amount of carboxyl groups, so if You have time You could try diferent times at this stage before KmNO4 addition

@@cigmmad alright, thanks!

It takes a couple of days, synthesis, washing, drying

Hello. We use a "toaster" oven because we can control the temperature around 50oC si GO do not decompose, that is why it is si slow. In a microwave You have to test if temperature do not rise 50 oC. Of course is better a laboratory convection oven.

Ok. thank you sir. What is the purpose of using NaNO3 in the initial chemical reaction? Is this possible to done this experiment without using sodium nitrate?

Hello @@priyankas4914 well, there are several routes for GO synthesis. For example, there is one based on sulfuric and fosforic acid which not employ NaNO3, this is call the Marcano process. The purpose of NaNO3 is to separate the graphite layers and allow access to KMnO4 to oxidize the double bonds.

Hi, we got about 2 g of GO for each batch. It could be more but our centrifugation machine has only 4000 rpm so the lighter fractions (less sheet, more exfoliated GO) are lost.

The solution is a commercial antifreeze for cars, it is used to reach 98ºC without evaporation, thus we recommend the antifreeze with the highest possible boiling point. However, because of the generated fumes, it has to be done in fumehood to avoid health issues. Another option is to use a sand or an oil bath to safely reach 98ºC, it is question which one is easier to control; for oil is usually very dirty. I hope it is useful, let us know if you do the experiment and how it works for you.

Hi. No, we don't add water at that moment (30 min) but after the periods at 5 oC and 30 oC, the water is added and temperature is risen to 98oC. You added water to a highly reactive H2SO4 and KMnO4 mixture, that is why You get the violent reaction.

ok thank you @@cigmmad

and please is there any achieved method to get reduced graphene oxide

@@wedadali9359yes, there are several and they depend on the level of reduction you want to achieve. For example you can use green reduction agents such as ascorbic acid, glucose, antioxidant additives (we can discuss options), or use hydrazine or NaBH4 if you have a lab with good safety as they are toxic or reactive.

ok. actually I did that by NaBH4 , but the structure was not good , I mean I didn't get single layer. I have also question please, I want to know about temp. why should control it less than 10C,and then with rGO should increase it. Thank you

It is because You need to remove Mn ions and thereafter You rinse with DI water to remove Cl ions

@@cigmmad thanks for the answer but i'm already used DI water and centrifuge before i use HCl solution. Is it ok? Let me know what matters if it is reversed🙏

@@28_fransiskusjulioalfonsos8 well, with DI You won't be able yo remove most of Mn ions. If You want to try it and later compare with HCl rinsing and do some.elemental analysis to see ir only water removes Mn let me know.

@@cigmmad thanks mate, i will do that later. hope u have a great day!

@@28_fransiskusjulioalfonsos8 good luck!

It is concentrated H2SO4, directly from the bottle, reactive or ACS grade.

lets us know if you get GO with this video!

@@cigmmad how can i contact you, i have a few question

@@TyNguyen-yh4fe send your email .ID, I willl contact you

We said "three volumes" because if the final volumen of the GO solution is, lets Say, 200 ml, we pour it in 15 mL centrufugue tubes and wash it three times

@@cigmmad ok got it

We use three volumes considering the final volumen of the GO solution. We use 15 mL centrifugation tubes to pour Go

@@nabaaanoor_ i hope it is useful and you can share your experience with us

Two days, synthesis one day, washing and drying second day.

@@cigmmad can you tell me it is a hummer method or modified one as research paper ( you have mentioned ) used the " term variation of hummer method" ? But not modified clearly

@@ridarida3154 we said "variation" because the reactants addition, how the H2O2-H2O mixture is added, how the material is washed are modifications of the Hummers report. You can check our paper here: 10.1016/j.matchemphys.2015.01.005

@@cigmmad ok thank you ✨stay blessed

No, on ne peut-pas parce-que l'ethanol i reaction fortement avec le acid sulphurique.

Quand peut on utilisé l'éthanol

on peut l'utilise apres le netoyage avec HCl 0.5 et apres H2O pour dehydrater le graphene oxide avant le mise au fourne, mais on peut avoir un peu de reduction de oxygene groups @@benedictekyamba

la machine a rotation n'a pas de scale de vitesse, mais on fixe la vitesse tel que un vortex aparait et tout se melange bien.(pardon pour mon Francais)

Applications range from energy storage, waste water treatment, water desalination, hydrogen generation, coatings for protection or electromagnetic management, drug delivery, sensors, composites and additives for plastics, between many more.

I suppose your Solution Is black, yes? It happens when the KMnO4 is added very fast or if H2O AND H2O2 Is added suddenly. The color shall be greenish-yellowish, not net Green or Yellow

I really made these mistakes, thank you, I will repeat the synthesis@@cigmmad

@@user-mj2mh6hk8n ok, let me know if it worked!

​@@cigmmadmine is too yellow, what do you think is my mistake?

@@rosellenunez6363 does It have sedimented material? Otherwise It could be fine. After rinsing and drying what color It has?