▎ 摘　　要

NOVELTY - Preparing graphene oxide having microwave absorbing properties comprises e.g. (i) taking flake graphite (C), potassium persulfate (K2S2O8), phosphorus pentoxide (P2O5) and concentrated sulfuric acid, (ii) reacting on constant temperature water bath, (iii) diluting and washing by deionized water to neutralize, drying and grinding to obtain oxidized graphite precursor, (iv) mixing concentrated sulfuric acid, potassium permanganate, potassium dichromate and oxidized graphite precursor to obtain mixture, (v) adding the mixture in a constant temperature environment and reacting to obtain dark green viscous liquid, (vi) mixing 98% concentrated sulfuric acid and deionized water and reacting with concentrated sulfuric acid, deionized water and hydrogen peroxide to obtain bright yellow solution, (vii) filtering bright yellow solution and washing by diluted hydrochloric acid and deionized water to obtain mixed solution, and (viii) drying mixed solution and grinding to obtain graphene oxide. USE - The method is useful for preparing graphene oxide having microwave absorbing properties. DETAILED DESCRIPTION - Preparing graphene oxide having microwave absorbing properties comprises (i) taking flake graphite (C), potassium persulfate (K2S2O8), phosphorus pentoxide (P2O5) and concentrated sulfuric acid with fraction of 98% in a ratio of 1-3:1-5:1-4:8-10, (ii) mixing by stirring, and reacting on constant temperature water bath at 50-90 degrees C for 6-8 hours, (iii) diluting and washing by deionized water to neutralize, then suction pumping by vacuum pump, drying at room temperature and grinding to obtain oxidized graphite precursor, (iv) taking 98% concentrated sulfuric acid (ml), potassium permanganate (g), potassium dichromate (g) in a ratio of 1-4:13-23:4-8:1-3, firstly mixing oxidized graphite precursor with 98% of concentrated sulfuric acid on ice water bath, stirring by slowly adding potassium permanganate and potassium dichromate to obtain mixture, (v) adding the mixture in a constant temperature environment of 30-40 degrees C and reacting for 2-4 hours to obtain dark green viscous liquid, (vi) mixing 98% concentrated sulfuric acid and first deionized water in a ratio of 1-3:2-4,measuring the first deionized water, and taking first deionized water, 98% concentrated sulfuric acid, second deionized water and hydrogen peroxide in a ratio of 28-30:1-3, controlling the temperature of the dark green viscous liquid less than or equal to 45 degrees C, continuously introducing chlorine gas into the thick liquid of green, adding first part of deionized water, after 12-18 minutes, then adding second part of deionized water and hydrogen peroxide, and reacting to obtain bright yellow solution, and then stopping introducing chlorine gas, (vii) filtering bright yellow solution and washing by diluted hydrochloric acid, and with deionized water until pH reaches to 6.8-7.2 to obtain mixed solution, and (viii) drying mixed solution, and grinding to obtain graphene oxide.