Highly oxidized graphene oxide and methods for production thereof
A highly oxidized form of graphene oxide and methods for production thereof are described in various embodiments of the present disclosure. In general, the methods include mixing a graphite source with a solution containing at least one oxidant and at least one protecting agent and then oxidizing the graphite source with the at least one oxidant in the presence of the at least one protecting agent to form the graphene oxide. Graphene oxide synthesized by the presently described methods is of a high structural quality that is more oxidized and maintains a higher proportion of aromatic rings and aromatic domains than does graphene oxide prepared in the absence of at least one protecting agent. Methods for reduction of graphene oxide into chemically converted graphene are also disclosed herein. The chemically converted graphene of the present disclosure is significantly more electrically conductive than is chemically converted graphene prepared from other sources of graphene oxide.
1. A method comprising:
providing a graphite source;
providing a solution comprising at least one oxidant and at least one protecting agent, wherein the at least one protecting agent is selected from the group consisting of trifluoroacetic acid, boric acid, trifluroacetic anhydride, boric anhydride, and combinations thereof; and wherein the at least one protecting agent is operable for protecting vicinal diols;
mixing the graphite source with the solution, wherein the mixing comprises stirring the graphite source with the solution; and
wherein the stirring results in the oxidizing of the graphite source with the at least one oxidant in the presence of the at least one protecting agent to form graphene oxide, wherein the at least one protecting agent protects vicinal diols during the stirring.
2. The method of claim 1 , wherein the at least one oxidant is selected from the group consisting of permanganate, ferrate, osmate, ruthenate, chlorate, chlorite, nitrate, osmium tetroxide, ruthenium tetroxide, lead dioxide, and combinations thereof.
3. The method of claim 1 , wherein the at least one oxidant comprises potassium permanganate.
4. The method of claim 1 , wherein the solution further comprises at least one acid solvent.
5. The method of claim 4 , wherein the at least one acid solvent is selected from the group consisting of oleum, sulfuric acid, chlorosulfonic acid, fluorosulfonic acid, trifluoromethanesulfonic acid, and combinations thereof.
6. The method of claim 4 , wherein the at least one acid solvent comprises sulfuric acid.
7. The method of claim 1 , wherein the at least one protecting agent chelates the vicinal diols.
8. The method of claim 1 , wherein the at least one protecting agent protects each alcohol of the vicinal diols individually.
9. A method comprising:
providing a graphite source;
providing a solution comprising at least one acid solvent, at least one oxidant and at least one protecting agent;
wherein the at least one protecting agent is selected from the group consisting of trifluoroacetic acid, boric acid, trifluroacetic anhydride, boric anhydride, and combinations thereof; and wherein the at least one protecting agent is operable for protecting vicinal diols; and
mixing the graphite source with the solution, wherein the mixing comprises stirring the graphite source with the solution; and wherein the stirring results in the oxidizing of the graphite source with the at least one oxidant in the presence of the at least one protecting agent to form graphene oxide, wherein the at least one protecting agent protects vicinal diols during the stirring.
10. The method of claim 9 , wherein the graphene oxide is more oxidized than graphene oxide prepared in the absence of the at least one protecting agent.
11. The method of claim 9 , wherein the at least one acid solvent is selected from the group consisting of oleum, sulfuric acid, chlorosulfonic acid, fluorosulfonic acid, trifluoromethanesulfonic acid, and combinations thereof.
12. The method of claim 9 , wherein the at least one acid solvent comprises sulfuric acid.
13. The method of claim 9 , wherein the at least one oxidant comprises potassium permanganate.
14. The method of claim 9 , wherein oxidizing the graphite source takes place at a temperature between about 30° C. and about 85° C.
15. The method of claim 9 , further comprising:
isolating the graphene oxide.
16. The method of claim 15 , further comprising:
reacting the graphene oxide with a derivatizing agent to form a functionalized graphene oxide.
17. The method of claim 15 , further comprising:
esterifying the graphene oxide to form an esterified graphene oxide.
18. The method of claim 15 , further comprising:
reducing the graphene oxide with at least one reducing agent to form chemically converted graphene.
19. The method of claim 18 , wherein the at least one reducing agent is selected from the group consisting of hydrazines, iodides, phosphines, phosphites, sulfides, sulfites, hydrosulfites, borohydrides, cyanoborohydrides, aluminum hydrides, boranes, hydroxylamine, diimine, dissolving metal reductions, hydrogen, and combinations thereof.
20. The method of claim 18 , wherein the at least one reducing agent comprises hydrazine.
21. The method of claim 18 , wherein the at least one reducing agent comprises hydrogen.
22. The method of claim 18 , further comprising:
esterifying the chemically converted graphene to form an esterified, chemically converted graphene.
23. The method of claim 18 , further comprising:
reacting the chemically converted graphene with a derivatizing agent to form a functionalized, chemically converted graphene.
24. The method of claim 18 , wherein the derivatizing agent comprises an aryl diazonium species.
25. The method of claim 23 , further comprising:
esterifying the functionalized, chemically converted graphene to form an esterified, functionalized, chemically converted graphene.
26. A method comprising:
providing a graphite source;
providing a solution comprising at least one acid solvent, potassium permanganate and at least one protecting agent, wherein the at least one protecting agent is operable for protecting vicinal diols;
wherein the at least one acid solvent is selected from the group consisting of oleum, sulfuric acid, fluorosulfonic acid, trifluoromethanesulfonic acid, and combinations thereof; and
wherein the at least one protecting agent is selected from the group consisting of trifluoroacetic acid; boric acid; trifluoroacetic anhydride; boric anhydride; and combinations thereof;
mixing the graphite source with the solution, wherein the mixing comprises stirring the graphite source with the solution; and
wherein the stirring results in the oxidizing of the graphite source with the potassium permanganate in the presence of the at least one protecting agent to form graphene oxide, wherein the at least one protecting agent protects vicinal diols during the stirring.
27. The method of claim 26 , wherein the at least one acid solvent comprises sulfuric acid.
28. The method of claim 26 , wherein oxidizing the graphite source takes place at a temperature between about 30° C. and about 85° C.
29. The method of claim 26 , wherein the graphene oxide is operable to slow the filtration rate of a liquid mixture selected from the group consisting of an aqueous liquid mixture, a non-aqueous liquid mixture, and combinations thereof.