▎ 摘　　要

NOVELTY - The preparation of graphene-coated silica nanoparticles involves modifying graphite powder with Hummers method to prepare graphene oxide, weighing silicon source precursor, adding into aqueous solution containing structural directing agent, adding aqueous ammonia solution, stirring, washing, sintering to obtain silica nanopowder, adding silica powder into deionized water, adding silane coupling agent, heating at reflux, forming a layer of silane coupling agent on surface of silica, and dissolving graphene oxide in mixed solvent comprising ethanol and deionized water. USE - Preparation method of graphene-coated silica nanoparticles (claimed). ADVANTAGE - The method enables preparation of graphene-coated silica nanoparticles using simple process in short time, and the prepared composite material has regular structure, high porosity, low density, and excellent hydrophobic effect. DETAILED DESCRIPTION - The preparation of graphene-coated silica nanoparticles involves (1) using graphite powder as raw material, modifying with Hummers method to prepare graphene oxide, (2) weighing silicon source precursor, adding into aqueous solution containing structural directing agent, adding aqueous ammonia solution, stirring for several hours, washing with ethanol and deionized water, sintering at 550 degrees C for 3 hours to obtain spherical silica nanopowder, (3) adding 1.0 g silica powder into 100 ml deionized water to form aqueous solution of silica, adding 1.0-2.0 ml silane coupling agent, heating at reflux in protective gas atmosphere for 24 hours, uniformly forming a layer of silane coupling agent on the surface of silica, (4) dissolving 50 mg graphene oxide in mixed solvent comprising 5 ml ethanol and 5 ml deionized water, ultrasonically treating to obtain modified silica aqueous solution, stirring at room temperature for 4 hours, adjusting pH value of the solution at 2-7, coating graphene on the surface of silica, dripping small amount of reducing agent solution, reducing graphene oxide, removing excess oxygen-containing functional groups on the surface of the graphene oxide to obtain graphene-coated silica material, centrifuging, filtering, and drying to obtain black powdery solid.