Graphene and ferroferric oxide@gold composite material and preparation method and application thereof

Abstract

The present disclosure relates to a graphene and Fe 3 O 4 -Au composite and a preparation method and a use thereof. The preparation method includes the following: firstly, preparing a thiol alkyl azide-modified Fe 3 O 4 -Au complex, and preparing an alkynylated graphene oxide by reacting a graphene oxide, which is activated by thionyl chloride, with a propargyl alcohol, and then performing a click reaction of the alkynyl group with the azide group between the thiol alkyl azide-modified Fe 3 O 4 -Au complex and the alkynylated graphene oxide with adding a catalysis under a nitrogen atmosphere condition to obtain the graphene and Fe 3 O 4 -Au composite. The method of preparing the graphene and Fe 3 O 4 -Au composite of the present disclosure has mild reaction conditions, and is simple and reliable.

1 . A method of preparing a graphene and Fe 3 O 4 -Au composite, comprising the following steps:
 (1) preparing a thiol alkyl azide-modified Fe 3 O 4 -Au complex and an alkynylated graphene oxide,   wherein, the preparing a thiol alkyl azide-modified Fe 3 O 4 -Au complex includes the following steps:   dispersing a nano-ferroferric oxide in a reductant solution, performing sonication and heating to 65° C. to 75° C., adding a chloroauric acid aqueous solution dropwise under stirring, stopping heating after reaction, and then stirring to conduct ripening reaction to obtain a Fe 3 O 4 -Au complex with a core-shell structure; and   placing the Fe 3 O 4 -Au complex and a thiol alkyl azide in a first solvent to perform a reaction at 40 to 45° C. under stirring in a protective atmosphere, and then rinsing repeatedly with a second solvent to obtain the thiol alkyl azide-modified Fe 3 O 4 -Au complex;   the preparing an alkynylated graphene oxide includes the following steps:   placing a graphene oxide in an activator to conduct an activating reaction at a condition of 65 to 75° C., and then adding propargyl alcohol to continue reacting for 20 to 28 h to obtain the alkynylated graphene oxide;   and   (2) preparing a graphene and Fe 3 O 4 -Au composite,   wherein, the thiol alkyl azide-modified Fe 3 O 4 -Au complex and the alkynylated graphene oxide prepared in the step (1) are dispersed in a third solvent, a catalyst is added, and the reaction is stirred in a protective atmosphere to collect a product that is the graphene and Fe 3 O 4 -Au composite.   
     
     
         2 . The method of preparing the graphene and Fe 3 O 4 -Au composite according to  claim 1 , wherein, in the step (2), the mass concentration ratio of the thiol alkyl azide-modified Fe3O4-Au complex to the alkynylated graphene oxide is 30-50:30-50. 
     
     
         3 . The method of preparing the graphene and Fe3O4-Au composite according to  claim 2 , wherein, in the step (2), the third solvent is dimethylformamide or tetrahydrofuran, and the catalyst is a mixture of N,N,N′,N″,N″-pentamethyldiethylenetriamine and cuprous bromide. 
     
     
         4 . The method of preparing the graphene and Fe3O4-Au composite according to  claim 1 , wherein, in step (1), the number of carbon atoms in the thiol alkyl azide is N, wherein 6<N<15; the mass ratio of the Fe3O4-Au complex to thiol alkyl azide is 100:0.4-2. 
     
     
         5 . The method of preparing the graphene and Fe3O4-Au composite according to  claim 4 , wherein, in the step (1), the activator is thionyl chloride, and the activating reaction time of the graphene oxide in the thionyl chloride is 20-28 h. 
     
     
         6 . The method of preparing the graphene and Fe3O4-Au composite according to  claim 1 , wherein in the step (1), the first solvent is toluene; the second solvent is a non-polar solvent, and the reaction time of the Fe3O4-Au complex and the thiol alkyl azide is 45-55 h. 
     
     
         7 . The method of preparing the graphene and Fe3O4-Au composite according to  claim 1 , wherein in the step (1), the nano-ferroferric oxide is prepared by a process including the following steps: dissolving 1.8-2.2 g of FeCl3.6H2O in 100±5 mL of distilled water, adding 0.8-1.2 g of FeCl2.4H2O with stirring in a nitrogen atmosphere, then adding ammonia water or sodium hydroxide solution dropwise until the pH of the reaction solution is raised to 8.8-9.5, heating to 80° C. to 90° C. for reacting for 20-30 min, and then conducting magnetic separation to obtain the nano-ferroferric oxide;
 in the steps for preparing the thiol alkyl azide-modified Fe3O4-Au complex, the reductant is sodium citrate, and the sodium citrate has a mass concentration of 1-3 mg/mL and a volume of 100±5 mL; the mass concentration of the chloroauric acid aqueous solution is 8-12 mg/mL, and its addition volume is 8-12 mL. 
 
     
     
         8 . The method of preparing the graphene and Fe3O4-Au composite according to  claim 1 , wherein in the step (1), the graphene oxide is prepared by a process including the following steps:
 adding 13-17 mL of concentrated sulfuric acid to a mixed system of 0.4-0.6 g of natural graphite and 0.5-0.6 g of sodium nitrate under an ice bath condition, then adding 1.3-1.7 g of potassium permanganate with maintaining the temperature of the reaction system as no higher than 5° C.; and   after the addition, heating the reaction system to 28-32° C. to react for 55-65 min, then adding 15-25 mL of deionized water to the reaction system, further heating to 90-99° C. to continue the reaction for 13-17 min, adding 65-75 mL of deionized water, then adding 2.0-3.0 mL of hydrogen peroxide dropwise, removing excess potassium permanganate to get a bright yellow solution; let the solution stand still for one day, then removing the supernatant, and washing the lower layer yellow solid with deionized water repeatedly until there is no acid and sulfate ion in the supernatant, and then freeze-drying to obtain the graphene oxide.   
     
     
         9 . A graphene and Fe3O4-Au composite prepared by the method of preparing the graphene and Fe3O4-Au composite according to  claim 1 . 
     
     
         10 . Use of the graphene and Fe3O4-Au composite according to  claim 9  in nuclear magnetic imaging, microwave thermoacoustic imaging, photoacoustic imaging or X-ray imaging.