Graphene quantum dots, their composites and preparation of the same
View Patent ↗Procedures for the synthesis of zero dimension GQDs based on exfoliation/reduction of surface passivated functionalized graphite oxide (f-GO PEG) are described. The synthesis procedures can include exfoliation/reduction f-GO PEG in presence of hydrogen gas, using focused solar radiation and under vacuum.
1. A method of making zero dimensional graphene quantum dots (0-D GQDs), the method comprising:
placing graphite oxide (GO) in a furnace, wherein the graphite oxide is surface passivated by polyethylene glycol under sonication to form a functionalized graphite oxide (f-GO PEG);
flushing the furnace with an inert gas at a temperature of about 20° C. to about 30° C. for about 15 minutes;
introducing hydrogen (H 2 ) into the furnace at a temperature of about 18° C. to about 33° C.;
heating the functionalized graphite oxide at about 200° C. in the presence of hydrogen (H 2 ); and
cooling the furnace to room temperature.
2. The method of claim 1 , wherein the inert gas is argon (Ar).
3. The method of claim 1 , further comprising dispersing the 0-D GQDs in water and dialyzing to separate pure 0-D GQDs from unreacted GO.
4. The method of claim 1 , wherein the heating at 200° C. is performed for at least 30 minutes.
5. The method of claim 1 , wherein the 0-D GQDs are water soluble.
6. The method of claim 1 , wherein the 0-D GQDs emit blue light upon exposure to UV light.
7. The method of claim 1 , wherein the 0-D GQDs are biocompatible.
8. The method of claim 1 , wherein the graphite oxide used to make the zero dimensional graphene quantum dots (0-D GQDs) is dried in a heated vacuum oven prior to practicing the method of claim 1 .
9. The method of claim 8 , wherein the heated vacuum oven is held at 50° C.
10. A method of making a composite of zero dimensional graphene Quantum Dots (0-D GQD) and one dimensional carbon nanotubes (1-D CNT), the method comprising:
placing a mixture of graphite oxide (GO) and MnNi 3 in a furnace;
flushing the furnace with an inert gas;
introducing hydrogen (H 2 ) into the furnace;
heating the mixture to about 200° C. in the presence of hydrogen for about 5 minutes;
heating the mixture to about 700° C.;
introducing acetylene to the furnace; and
cooling the furnace to room temperature.
11. The method of claim 10 , wherein the inert gas is argon (Ar).
12. The method of claim 10 , wherein flushing the furnace with argon is for about 15 minutes.
13. The method of claim 10 , wherein flushing the furnace with an inert gas is performed at about a temperature of 20° C.-30° C.
14. The method of claim 10 , wherein the mixture is heated with acetylene for about 20 minutes.
15. The method of claim 10 , wherein the method also produces two-dimensional graphene sheets.
16. The method of claim 10 , further comprising dispersing the 0-D GQDs in water and dialyzing to isolate 0-D GQDs.
17. The method of claim 10 , wherein the dried graphite oxide (GO) and MnNi 3 are ground.
18. The method of claim 10 , wherein the 0-D GQDs emit blue light upon exposure to UV light.
19. The method of claim 10 , wherein the 0-D GQDs are biocompatible.
20. The method of claim 10 , wherein the dried graphite oxide (GO) is dried in a heated vacuum oven prior to practicing the method of claim 10 .
21. The method of claim 20 , wherein the heated vacuum oven is held at 50° C.
22. The method of claim 10 , wherein the graphite oxide is functionalized graphite oxide (f-GO).
23. The method of claim 22 , wherein the graphite oxide is surface passivated functionalized graphite oxide (f-GO PEG).
24. The method of claim 23 , wherein the surface passivated functionalized graphite oxide (f-GO PEG) is manufactured under sonication.
25. The method of claim 23 , wherein the 0-D GQDs are water soluble.
26. The method of claim 23 , wherein the 0-D GQDs are biocompatible.