Method and system for producing graphene and functionalized graphene

Abstract

This disclosure includes a process that unexpectedly can produce very inexpensive graphene, functionalized graphenes, and a new compound called graphenol in particulate or dispersions in solvents. The process can also produce graphene layers on metallic and nonmetallic substrates. Further, the graphenol, functionalized graphenes, and graphene can be utilized to form nanocomposites that yield property improvements exceeding anything reported previously.

What is claimed is: 
     
         1 . A process for making graphenol or functionalized graphenes, said processes comprising:
 extracting a humic acid solution from a carbonaceous material via a basic solution, said basic solution having a hydroxide concentration of at least approximately 0.005 moles per liter; and   chemically reducing at least one of a carbonyl group portion and a carboxylic acid group portion of said humic acid solution, said chemically reducing comprising:   placing said humic acid solution in a pressure reactor;   adding a hydrogenation catalyst to said humic acid solution;   purging said pressure reactor with an inert gas;   charging said pressure reactor with hydrogen gas;   heating said humic acid solution; and   removing said hydrogenation catalyst from said humic acid solution,   thereby producing a solution containing graphenol comprising the following general structure:   
       
         
           
           
               
               
           
         
       
     
     
         2 . The process of  claim 1 , wherein said carbonaceous material comprises lignite or peat. 
     
     
         3 . The process of  claim 1 , wherein said carbonaceous material comprises leonardite. 
     
     
         4 . The process of  claim 3 , wherein said basic solution is chosen from the group consisting of sodium hydroxide, potassium hydroxide, and ammonium hydroxide. 
     
     
         5 . The process of  claim 3 , wherein said basic solution comprises ammonium hydroxide, and further comprising removing said ammonium hydroxide by heating after chemically reducing said at least one of a carbonyl group portion and a carboxylic acid group portion. 
     
     
         6 . The process of  claim 1 , wherein removing said hydrogenation catalyst comprises removing said hydrogenation catalyst by filtering. 
     
     
         7 . The process of  claim 1 , further comprising removing said basic solution via a strong acid ion exchange resin. 
     
     
         8 . The process of  claim 1 , wherein said inert gas comprises a noble gas. 
     
     
         9 . The process of  claim 8 , wherein said noble gas comprises argon. 
     
     
         10 . The process of  claim 1 , wherein said hydrogenation catalyst is chosen from the group consisting of Raney nickel, copper chromium oxide, and ruthenium oxide. 
     
     
         11 . The process of  claim 1 , further comprising:
 drying said solution containing graphenol, thereby producing a powder or sheet of graphenol on a substrate; and   heating said powder or sheet of graphenol in a second inert gas at approximately 400 to 800° C.,   thereby producing said graphene.   
     
     
         12 . The process of  claim 11 , wherein said second inert gas comprises argon. 
     
     
         13 . The process of  claim 12 , wherein said argon further comprises a partial pressure of hydrogen gas. 
     
     
         14 . The process of  claim 1 , wherein chemically reducing reduces said carbonyl and carboxylic acid functional group portions to alcoholic groups, and wherein a fused aromatic ring structure within the sheet is retained. 
     
     
         15 . A process for making graphenol, said process comprising:
 extracting a humic acid solution from a carbonaceous material via either a basic solution or dimethylformamide; and   chemically reducing a carboxylic acid portion of said humic acid solution with hydrazine thereby producing graphenol comprising the following general structure:   
       
         
           
           
               
               
           
         
       
     
     
         16 . A process for making graphene, said process comprising:
 extracting a humic acid solution from a said carbonaceous material via a basic solution;   coating a substrate with said humic acid solution and drying said coated substrate to form a film;   pyrolytically reducing said film to graphene.   
     
     
         17 . The process of  claim 16 , wherein said carbonaceous material comprises lignite or peat. 
     
     
         18 . The process of  claim 16 , wherein said basic solution comprises ammonium hydroxide. 
     
     
         19 . The process of  claim 16 , wherein coating comprises spin coating. 
     
     
         20 . The process of  claim 16 , wherein coating employs a doctor blade or drawdown bar. 
     
     
         21 . The process of  claim 16 , wherein said pyrolytic reduction is carried out under an inert atmosphere of noble gas. 
     
     
         22 . The process of  claim 16 , wherein said pyrolytic reduction is carried out under an argon atmosphere, said argon atmosphere containing a partial pressure of hydrogen.