▎ 摘　　要

NOVELTY - Preparing magnetically modified graphene oxide hydrogel, comprises (i) preparing graphene oxide; (ii) dissolving graphene oxide and thiourea in hydrobromic acid under the protection of inert gas, reacting for 20-30 minutes, refluxing, cooling to room temperature, reacting, adding sodium hydroxide solution, reacting, and adjusting pH, recrystallizing and drying to obtain mercapto graphene oxide; (iii) adding L-cysteine and mercapto graphene oxide to a phosphate buffer solution having a pH of 7.4-8, reacting for 3-4 hours, taking out the product and immersing in deionized water for 2-3 days, drying to obtain modified graphene oxide hydrogel; and (iv) dissolving and mixing ferric chloride hexahydrate and ferrous sulfate heptahydrate under the protection of inert gas, and adding to the modified graphene oxide hydrogel solution, adjusting the pH to 8-10, reacting, separating hydrogel, washing with deionized water, drying to obtain magnetically modified graphene oxide hydrogel. USE - The method is useful for preparing magnetically modified graphene oxide hydrogel. ADVANTAGE - The method has good separation and regeneration performance and adsorption performance of heavy metal ion; and separates quickly absorbing material with the waste water. DETAILED DESCRIPTION - Preparing magnetically modified graphene oxide hydrogel, comprises (i) mixing graphite powder and sodium nitrite in a water bath of 0-5 degrees C, adding concentrated sulfuric acid, reacting for 1-2 hours and adding potassium dichromate, reacting for 1-2 hours, and adding dichloromethane is as a solvent, m-chloroperoxybenzoic acid, reacting for 1-2 hours, heating to 20-25 degrees C, and adding deionized water to continue the reaction for 0.5-1 hours, filtering, washing to neutral, vacuum drying at 40-45 degrees C to obtain graphene oxide; (ii) dissolving graphene oxide and thiourea in hydrobromic acid under the protection of inert gas, reacting for 20-30 minutes, refluxing at 50-60 degrees C for 12-15 hours, cooling to room temperature, and reacting at 0-5 degrees C for 20-30 minutes, adding sodium hydroxide solution, reacting for 8-12 hours, and adjusting the pH of the solution to 2-3 deionized water, recrystallizing and drying under vacuum at 45-50 degrees C to obtain mercapto graphene oxide; (iii) adding L-cysteine and mercapto graphene oxide to a phosphate buffer solution having a pH of 7.4-8, reacting for 3-4 hours, taking out the product and immersing in deionized water for 2-3 days, drying at 40-50 degrees C to obtain modified graphene oxide hydrogel; and (iv) dissolving and mixing ferric chloride hexahydrate and ferrous sulfate heptahydrate under the protection of inert gas, and adding to the modified graphene oxide hydrogel solution, adjusting the pH to 8- 10, reacting at 30-40 degrees C for 3-4 hours, separating the hydrogel, washing with deionized water, drying in vacuum at 45-50 degrees C to obtain magnetically modified graphene oxide hydrogel. An INDEPENDENT CLAIM is also included for use of a magnetically modified graphene oxide hydrogel obtained for preparing a magnetically modified graphene oxide hydrogel for identifying various heavy metal ions.