Chemical synthesis for graphene sheets greater than 1 μm in length
A method for preparing a graphene sheet greater than 1 μm in length that includes: combining graphitic oxide with a solvent having a ratio of from about 50:50 to about 80:20 deionized water and ethanol to form a graphitic oxide solution; mixing a solution of NaBH 4 and deionized water and the graphitic oxide solution to form a mixture having a concentration of from 10 mmolar to 20 mmolar NaBH 4 ; depositing the mixture on a substrate to form a sheet; and heating the mixture at a temperature of from 25° C. to 85° C. for from 3 to 30 minutes.
1. A method for preparing a graphene sheet greater than 1 μm in length, the method comprising:
combining graphitic oxide with a solvent comprising ethanol and deionized water to form a graphitic oxide solution;
mixing a reductant and the graphitic oxide solution to form a mixture, wherein the reductant is NaBH 4 , and wherein the concentration of the reductant in the mixture is from 5 mmolar to 25 mmolar; and
heating the mixture at a temperature of from 25° C. to 90° C. for from 3 to 30 minutes.
2. The method for preparing a graphene sheet according to claim 1 , wherein the volumetric ratio of deionized water to ethanol is from about 50:50 to about 80:20.
3. The method for preparing a graphene sheet according to claim 1 , wherein the volumetric ratio of deionized water to ethanol is from about 65:35 to about 75:25.
4. The method for preparing a graphene sheet according to claim 1 , wherein the NaBH 4 is mixed with deionized water to form a solution prior to mixing with the graphitic oxide solution.
5. The method for preparing a graphene sheet according to claim 4 , wherein the concentration of the reductant in the mixture is from 10 mmolar to 20 mmolar.
6. The method for preparing a graphene sheet according to claim 4 , wherein the concentration of the reductant in the mixture is less than 15 mmolar.
7. The method for preparing a graphene sheet according to claim 1 , wherein the heating of the mixture is carried out at a temperature of from 50° C. to 85° C.
8. A method for preparing a graphene sheet greater than 1 μm in length, the method comprising:
combining graphitic oxide with a solvent comprising deionized water and ethanol to form a graphitic oxide solution;
mixing a reductant and the graphitic oxide solution to form a mixture, wherein the reductant is NaBH 4 , and wherein the concentration of the reductant in the mixture is from 10 mmolar to 20 mmolar; and
heating the mixture at a temperature of from 50° C. to 85° C. for from 3 to 30 minutes.
9. The method for preparing a graphene sheet according to claim 8 , wherein the volumetric ratio of deionized water to ethanol is from about 50:50 to about 80:20.
10. The method for preparing a graphene sheet according to claim 8 , wherein the volumetric ratio of deionized water to ethanol is from about 65:35 to about 75:25.
11. The method for preparing a graphene sheet according to claim 8 , wherein the NaBH 4 is mixed with deionized water to form a solution prior to mixing with the graphitic oxide solution.
12. The method for preparing a graphene sheet according to claim 11 , wherein the concentration of the reductant in the mixture is less than 15 mmolar.
13. The method for preparing a graphene sheet according to claim 12 , wherein the heating of the mixture is carried out at a temperature of from 75° C. to 85° C.
14. The method for preparing a graphene sheet according to claim 13 , wherein the heating of the mixture is carried out for from 5 to 15 minutes.
15. A method for preparing a graphene sheet greater than 1 μm in length, the method comprising:
combining graphitic oxide with a solvent comprising a first deionized water and ethanol to form a graphitic oxide solution, wherein the volumetric ratio of deionized water to ethanol is from about 50:50 to about 80:20;
mixing a solution of NaBH 4 and a second deionized water and the graphitic oxide solution to form a mixture, wherein the concentration of NaBH 4 in the mixture is from 10 mmolar to 20 mmolar; and
heating the mixture at a temperature of from 25° C. to 90° C. for from 3 to 30 minutes.
16. The method for preparing a graphene sheet according to claim 15 , wherein the volumetric ratio of the first deionized water to ethanol is from about 65:35 to about 75:25.
17. The method for preparing a graphene sheet according to claim 16 , wherein the concentration of the reductant NaBH 4 in the mixture is from 13 mmolar to 17 mmolar.
18. The method for preparing a graphene sheet according to claim 17 , wherein the heating of the mixture is carried out at a temperature of from 75° C. to 85° C.
19. The method for preparing a graphene sheet according to claim 18 , wherein the heating of the mixture is carried out for from 5 to 15 minutes.