Highly crystalline 3D graphene
Disclosed here is a composition comprising at least one graphene aerogel comprising a three-dimensional structure of graphene sheets, wherein the graphene sheets are covalently interconnected, and wherein the graphene aerogel is highly crystalline. Also described is a method for making a graphene aerogel, comprising preparing a mixture comprising a graphene oxide suspension and at least one catalyst; curing the reaction mixture to produce a wet gel; drying the wet gel to produce a dry gel; and pyrolyzing the dry gel at a temperature of 1500-3500° C. to produce the graphene aerogel.
1. A composition comprising at least one graphene aerogel comprising a three-dimensional structure of graphene sheets, wherein the graphene sheets are covalently interconnected, wherein the graphene aerogel has a Raman spectra in which I D /I G is 0.7 or less, wherein the graphene aerogel has an electrical conductivity of 200-600 S/m and a density of 80 mg/ml or less, and wherein the graphene aerogel is produced by a process comprising thermal annealing at a temperature of 1500-3500° C.
2. The composition of claim 1 , wherein the graphene aerogel has a Raman spectra in which I G′ /I G is 0.5 or more.
3. The composition of claim 1 , wherein the graphene aerogel has an average crystallite size L a of 30 nm or more.
4. The composition of claim 1 , wherein the graphene aerogel has an electrical conductivity of 300-600 S/m.
5. The composition of claim 1 , wherein the graphene aerogel has an oxidation temperature T O of 700° C. or more.
6. The composition of claim 1 , wherein the graphene aerogel has a Young's modulus of 50 MPa or more.
7. The composition of claim 1 , wherein the graphene aerogel has a density of 60 mg/ml or less.
8. The composition of claim 1 , wherein the graphene aerogel has a BET surface area of 300 m 2 /g or more.
9. The composition of claim 1 , wherein the graphene aerogel has a pore volume of at least 1 cm 3 /g.
10. The composition of claim 1 , wherein pores having a diameter of 100 nm or less account for 50% or more of the total pore volume of the graphene aerogel.
11. The composition of claim 1 , wherein pores having a diameter of 100 nm or less account for 50% or more of the total pore number of the graphene aerogel.
12. The composition of claim 1 , wherein 70% or more of the covalent bonds interconnecting the graphene sheets are sp 2 carbon bonds.
13. The composition of claim 1 , wherein the graphene aerogel has an atomic oxygen content of 5% or less.
14. The composition of claim 1 , wherein the graphene aerogel is in the form of a monolith having at least one lateral dimension of 1 mm or more.
15. The composition of claim 1 , wherein the graphene aerogel consists essentially of covalently interconnected graphene sheets.
16. The composition of claim 1 , wherein the composition does not comprise a macroporous foam.
17. A method for making the graphene aerogel of claim 1 , comprising:
preparing a mixture comprising a graphene oxide suspension and at least one catalyst;
curing the mixture to produce a wet gel;
drying the wet gel to produce a dry gel; and
thermally annealing the dry gel at a temperature of 1500-3500° C. to produce the graphene aerogel.
18. The method of claim 17 , wherein the dry gel is thermally annealed at a temperature of 2000-3000° C.
19. The method of claim 17 , wherein the mixture consists essentially of the graphene oxide, the catalyst, and at least one solvent.
20. A device comprising the composition of claim 1 .