▎ 摘　　要

NOVELTY - Preparation method of graphene oxide/silicon dioxide composite coating involves (a) reacting natural micron or nano-graphite with strong oxidizing agent, (b) washing graphene oxide slurry with water, (c) ultrasonically dispersing the dried graphene oxide slurry in water, (d) adding silicon dioxide to uniform graphene oxide dispersion liquid, stirring, carrying out ultrasonic treatment, centrifuging and drying, and (e) adding the solid product to deionized water and adding mixed solution of hydrazine hydrate solution and concentrated aqueous ammonia. USE - Method is useful for the preparation of graphene oxide/silicon dioxide composite coating (claimed). ADVANTAGE - The method enables preparation of graphene oxide/silicon dioxide composite coating with high stability and dispersibility and excellent formaldehyde adsorption function. The composite coating releases negative ions and resists bacteria. DETAILED DESCRIPTION - Preparation method of graphene oxide/silicon dioxide composite coating involves (a) reacting natural micron or nano-graphite with strong oxidizing agent at 20-40 degrees C for 1-3 hours to obtain graphene oxide slurry, (b) washing 1-2 g graphene oxide slurry with water until the slurry is neutral, (c) drying the graphene oxide slurry and ultrasonically dispersing the dried graphene oxide slurry in water to obtain uniform graphene oxide dispersion liquid, (d) adding silicon dioxide to the uniform graphene oxide dispersion liquid, stirring, carrying out ultrasonic treatment, centrifuging and drying to obtain graphene oxide-loaded silicon dioxide powder solid product, (e) adding the solid product to deionized water, adding a mixed solution of hydrazine hydrate solution and concentrated aqueous ammonia, uniformly stirring, carrying out water bath reaction, cooling, washing with water, centrifuging and drying to obtain graphene oxide/silicon dioxide composite material, (f) adding distilled water to the graphene oxide/silicon dioxide composite material and carrying out ultrasonic dispersion at an ultrasonic power of 60-180 W for 3-7 hours, and (g) mixing graphene oxide/silicon dioxide composite material and aqueous polyurethane in a mass ratio of 1-10:100 with distilled water and carrying out ultrasonic dispersion at an ultrasonic power of 60-180 W for 4-8 hours to obtain the graphene oxide/silicon dioxide composite coating.