▎ 摘　　要

NOVELTY - The preparation method of graphene oxide involves adding natural graphite, sodium nitrate and potassium permanganate to concentrated sulfuric acid under stirring, continuously stirring the mixture at 0-4 degrees C for 2 hours, heating the mixture at 35 plus minus 5 degrees C, then continuously stirring for 20-40 minutes and heating at 90-95 degrees C, stirring and heating the mixture for 15-30 minutes, then adding hydrogen peroxide, centrifuging supernatant, washing the supernatant with dilute hydrochloric acid and water to obtain liquid, and freeze-drying at -20 degrees C to -25 degrees C for 2-4 days. USE - The method is useful for preparing graphene oxide, which is useful for removing contaminants from water, where the contaminants contain heavy metals and bisphenol A (all claimed). ADVANTAGE - The method enables preparation of graphene oxide, which ensures quick and efficient adsorption of bisphenol A and heavy metals and other contaminants to provide water with drinking water standards. DETAILED DESCRIPTION - The preparation method of graphene oxide involves adding natural graphite, sodium nitrate and potassium permanganate to concentrated sulfuric acid under stirring, where the weight ratio of natural graphite and potassium permanganate is 1:1.5-1:6, continuously stirring the mixture at 0-4 degrees C for 2 hours, heating the mixture at 35 plus minus 5 degrees C, then continuously stirring for 20-40 minutes and heating at 90-95 degrees C, stirring and heating the mixture for 15-30 minutes, then adding hydrogen peroxide, centrifuging supernatant, washing the supernatant with dilute hydrochloric acid and water to obtain liquid, and freeze-drying at -20 degrees C to -25 degrees C for 2-4 days. INDEPENDENT CLAIMS are included for the following: (1) graphene oxide prepared by the method; and (2) use of graphene oxide for removing contaminants from water.