Nanocomposite of graphene and metal oxide materials
Nanocomposite materials comprising a metal oxide bonded to at least one graphene material. The nanocomposite materials exhibit a specific capacity of at least twice that of the metal oxide material without the graphene at a charge/discharge rate greater than about 10 C.
1. A nanocomposite material comprising a metal oxide bonded directly to a graphene layer, wherein the graphene layer consists essentially of 1 to 147 graphene sheets, the nanocomposite material having a specific capacity at least twice that of the metal oxide without the graphene layer at a charge/discharge rate greater than about 10 C.
2. The nanocomposite material of claim 1 wherein the graphene layer has a carbon to oxygen ratio of 10-500:1.
3. The nanocomposite material of claim 1 wherein the metal oxide is M x O y , and where M is Ti, Sn, Ni, Mn, V, Si, or Co, or is a combination thereof.
4. The nanocomposite material of claim 1 wherein the metal oxide is titania.
5. The nanocomposite material of claim 1 wherein the metal oxide is tin oxide.
6. The nanocomposite material of claim 1 including a plurality of graphene layers having metal oxide bonded directly thereto, the plurality of graphene layers forming a nanoarchitecture with the metal oxide substantially uniformly distributed throughout the nanoarchitecture.
7. The nanocomposite material of claim 1 wherein the graphene layer comprises functionalized graphene sheets.
8. The nanocomposite material of claim 1 wherein the graphene layer consists essentially of 6 to 29 graphene sheets.
9. The nanocomposite material of claim 8 wherein the graphene layer comprises functionalized graphene sheets.
10. The nanocomposite material of claim 4 wherein the titania is in a mesoporous form.
11. The nanocomposite material of claim 4 wherein the mesoporous titania is in a rutile crystalline structure.
12. A method comprising:
providing graphene layers in a first mixture, the graphene layers having a first surface and a second surface and thicknesses of 0.5 to 50 nm;
dispersing the graphene layers with a surfactant;
adding a metal oxide precursor to said dispersed graphene layers to form a second mixture;
precipitating the metal oxide from the second mixture on surfaces of the dispersed graphene layers to form a nanocomposite material comprising a metal oxide bonded directly to the first and second surfaces of a graphene layer; and
wherein the precipitating the metal oxide further comprises condensing the metal oxide at a temperature of less than 100° C. to form rutile crystalline metal oxide bonded directly to the first and second surfaces of the graphene layer.
13. The method of claim 12 wherein the metal oxide comprises tin oxide.
14. The method of claim 12 wherein the metal oxide comprises titania.
15. The method of claim 14 wherein the titania is mesoporous.