▎ 摘　　要

NOVELTY - Preparation of graphene-based material involves mixing tetraethyl orthosilicate as silicon source with a mixed solution comprising ammonia and ethanol solution, hydrolyzing, obtaining silica colloidal microspheres, dispersing resultant microspheres in water, adding an aqueous solution of polydiallyldimethylammonium chloride, obtaining positively charged silica microspheres, dispersing resultant in water, dripping small-sized graphene oxide, ultrasonically processing and centrifuging. USE - Preparation of graphene-based material is used as catalyst for reduction of 4-nitrobenzene. ADVANTAGE - The method enables preparation of graphene-based material having excellent dispersibility and catalytic activity. DETAILED DESCRIPTION - Preparation of graphene-based material involves mixing tetraethyl orthosilicate as silicon source having concentration of 0.2 M with a mixed solution comprising 0.8-2.5 M ammonia and 34 M ethanol solution, stirring, hydrolyzing, obtaining silica colloidal microspheres, dispersing resultant microspheres in water, adding an aqueous solution of polydiallyldimethylammonium chloride, stirring, assembling polydiallyldimethylammonium chloride on silica microspheres by electrostatic interaction, obtaining positively charged silica microspheres, dispersing graphene sheets in water, obtaining an aqueous dispersion, centrifuging at high speed for 5 minutes, separating supernatant, obtaining small-sized graphene oxide, dispersing positively charged silica microspheres in water, dripping small-sized graphene oxide, ultrasonically processing at more than 150 W for 30 minutes and centrifuging for 5 minutes.