Mesoporous metal oxide graphene nanocomposite materials

Abstract

A nanocomposite material formed of graphene and a mesoporous metal oxide having a demonstrated specific capacity of more than 200 F/g with particular utility when employed in supercapacitor applications. A method for making these nanocomposite materials by first forming a mixture of graphene, a surfactant, and a metal oxide precursor, precipitating the metal oxide precursor with the surfactant from the mixture to form a mesoporous metal oxide. The mesoporous metal oxide is then deposited onto a surface of the graphene.

1 . A method comprising:
 providing graphene;   mixing the graphene with a surfactant and a metal oxide precursor;   precipitating the metal oxide precursor with the surfactant to form a mesoporous metal oxide; and   depositing the mesoporous metal oxide onto surfaces of the graphene;   forming a nanocomposite material with the mesoporous metal oxide bonded directly to the surfaces of the graphene.   
     
     
         2 . The method of  claim 1  wherein the graphene comprises functionalized graphene sheets prepared by thermal expansion of graphite oxide. 
     
     
         3 . The method of  claim 1  further comprising dispersing the graphene in the surfactant to yield dispersed graphene layers comprising 1 to 127 graphene sheets, and bonding the mesoporous metal oxide directly to the surfaces of the graphene layers. 
     
     
         4 . The method of  claim 1  wherein the surfactant is a non-ionic surfactant, 
     
     
         5 . The method of  claim 1  wherein the non-ionic surfactant is a tri-block copolymer. 
     
     
         6 . The method of  claim 1  wherein the forming of the nanocomposite material with the mesoporous metal oxide bonded directly to the surfaces of the graphene comprises heating the mixture from 100 to 500° C. to condense the mesoporous metal oxide on the surfaces of the graphene. 
     
     
         7 . The method of  claim 1  wherein the mesoporous metal oxide of the nanocomposite material has pores ranging in size from about 1 nm to about 30 nm. 
     
     
         8 . The method of  claim 1  wherein the mesoporous metal oxide of the nanocomposite material has a thickness ranging from about 0.5 nm to about 50 nm. 
     
     
         9 . The method of  claim 1  further comprising dispersing the graphene in the surfactant prior to mixing the graphene with the metal oxide precursor. 
     
     
         10 . The method of  claim 3  further comprising forming the nanocomposite material into open stacked-card structures of the multiple graphene layers coated with mesoporous metal oxide. 
     
     
         11 . The method of  claim 1  wherein the metal oxide comprises silica. 
     
     
         12 . The method of  claim 1  further comprising generally uniformly distributing the graphene and mesoporous metal oxide throughout the nanocomposite material.