▎ 摘　　要

NOVELTY - Graphene oxide is prepared based on mixed acid system by washing crystalline graphite flake raw material, drying, crushing, ultrasonicating graphite powder with intercalating agent i.e. 1st acid component to obtain graphite in 1st acid component, adding dispersing agent, dispersing for 0.5-3 hours to obtain 1st acid system, crushing oxidant, dissolving in 2nd acid component to obtain oxidant in 2nd acid component, adding long chain organic acid, ultrasonicating, cooling to obtain 2nd acid system, and dropwise adding 1st acid system to 2nd acid system. USE - Preparation of graphene oxide based on mixed acid system for graphene preparation (claimed). ADVANTAGE - The preparation of graphene oxide based on mixed acid system avoids graphene oxide agglomeration, reduces non-uniform reduction, reduces amount of acid, reduces corrosion, increases reaction efficiency, and yields large graphene sheets with large specific surface area and better product quality. DETAILED DESCRIPTION - Graphene oxide is prepared based on mixed acid system by washing crystalline graphite flake raw material, drying, crushing through 200-mesh sieve to obtain graphite powder, ultrasonicating graphite powder with intercalating agent i.e. 1st acid component to obtain 0.1-1 g/ml graphite in 1st acid component i.e. organic acid and/or inorganic acid, adding dispersing agent, ultrasonically dispersing for 0.5-3 hours to obtain 1st acid system, crushing oxidant, dissolving in 2nd acid component at 40-60 degrees C to obtain 0.5-5 g/ml oxidant in 2nd acid component i.e. weak organic acid and/or weak inorganic acid, adding long chain organic acid i.e. 10 carbon-containing saturated organic acid to oxidant-2nd acid system with ratio of graphite powder:long chain organic acid of 100:0.1-1, ultrasonicating for 0.5 hour, naturally cooling to obtain 2nd acid system, dropwise adding 1st acid system to 2nd acid system at speed of 1-2 drops/s to obtain mixed solution with volume ratio which follows equation (Cgraphitex V1st acid system)/(Coxidantx V2nd acid system)=1:2-8 in which Cgraphite is the concentration of graphite in 1st acid system, V1st acid system is the volume of 1st acid system, Coxidantis the concentration of oxidant in 2nd acid system, and V2nd acid system is the volume of the 2nd acid system, ultrasonically mixing mixture at 70-100 degrees C for 0.5-3 hours, dropwise adding water into mixture, standing for 3-10 minutes to obtain liquid mixture in which volume of water follows equation (Cgraphitex V1st acid system)/( rho waterx Vwater)=1:20-50, ultrasonically mixing liquid mixture for 0.5-3 hours, centrifuging at 4000 r/minute for 5 minutes, collecting supernatant, adding to 2-5% ammonium sulfate, salting out, filtering, washing filter cake with deionized water, washing with alcohol, and drying. An INDEPENDENT CLAIM is included for preparation of graphene which involves mixing prepared graphene oxide and high boiling point dispersing agent, ultrasonically dispersing to obtain 0.1-1 g/ml graphene oxide dispersion, adding reducing agent i.e. organic acid and/or organic acid salt with mass ratio graphene oxide:reducing agent of 1:2-8, heating by microwave of 400-900 W for 5-30 minutes, ultrasonically stripping at 100-600 W for 0.5-3 hours, adding water which is equal to volume of graphene oxide dispersion, filtering, washing with water, and drying.