Functionalized graphene sheets having high carbon to oxygen ratios
Functionalized graphene sheets having a carbon to oxygen molar ratio of at least about 23:1 and method of preparing the same.
1. Functionalized graphene sheets having a carbon to oxygen molar ratio of at least about 23:1 and comprising fully exfoliated single sheets of graphene, and wherein the functionalized graphene sheets are dry.
2. The functionalized graphene sheets of claim 1 , wherein the carbon to oxygen ratio is at least about 28:1.
3. The functionalized graphene sheets of claim 1 , wherein the carbon to oxygen ratio is at least about 50:1.
4. The functionalized graphene sheets of claim 1 , wherein the carbon to oxygen ratio is at least about 75:1.
5. The functionalized graphene sheets of claim 1 further comprising functionalized graphene sheets having a surface area of between about 350 and about 2400 m 2 /g.
6. The functionalized graphene sheets of claim further comprising functionalized graphene sheets having a surface area of between about 400 and about 2400 m 2 /g.
7. The functionalized graphene sheets of claim 1 further comprising functionalized graphene sheets having a surface area of between about 500 and about 2400 m 2 /g.
8. The functionalized graphene sheets of claim 1 further comprising functionalized graphene sheets having a surface area of between about 800 and about 2400 m 2 /g.
9. A method for making functionalized graphene sheets as claimed in claim 1 , comprising heating graphite oxide and/or functionalized graphene sheets having a carbon to oxygen ratio of less than about 23:1 at a temperature of at least about 750° C. for a time sufficient to generate functionalized graphene sheets having a carbon to oxygen molar ratio of at least about 23:1 wherein the functionalized graphene sheets comprise fully exfoliated single sheets of graphene and wherein the functionalized graphene sheets are dry.
10. The method of claim 9 , wherein the temperature is at least about 850° C. and the heating time is at least about 2 minutes.
11. The method of claim 9 , wherein the temperature is at least about 950° C. and the heating time is at least about 2 minutes.
12. The method of claim 9 , wherein the heating time is at least 15 minutes.
13. The method of claim 9 , wherein the heating is conducted in an inert atmosphere.
14. The method of claim 9 , wherein the heating is conducted in a reducing atmosphere.