Hossem Belhamdi

The most straightforward way is to rinse the GO product multiple time with ample amount of deionized water. This process can be accelerated if you have big conical tubes and a powerful centrifugal machine. After 5-6 rounds of cleaning, the pH value should rise to near 7. [You question reminds me of the arduous GO purification process I experienced 3 years ago.]

Dear Vinay S P,

I did all the steps but no improvement in the value, could you please tell me which additives !!

Dear Tianyu Liu

Thank you for your advice, I want to let you know that the solution was diluted with 2L deionized water, after washing the value rose near to 4

Hossem Belhamdi My personal experience and partition theory suggest that washing multiple times is better than dumping a large amount of water at once. Also, be cautious about introducing any additives, e.g., alkaline, to neutralize the acid, they could bring in other impurities such as salts.

Dear Tianyu Liu

When, even in papers, it is described that several washings should be carried out, do you mean that every time centrifugation should be done? What is the ideal rpm? thank you very much!

Maria Magro

I suggest doing centrifugation every time. There is not an ideal rpm, as long as the centrifugation can separate GO from its solvent. Low rpm typically requires long duration though.

@Tianyu Liu

What about temperature !??

Hossem Belhamdi I did the purification at room temperature. Slightly elevating temperature could facilitate the exchange of protons, but be cautious that increasing temperature shouldn't change the physical state or the chemical composition of GO.