▎ 摘　　要

NOVELTY - The method for the preparation of high-dispersion magnetic graphene nano-adsorbent involves dispersing graphene oxide in deionized water, dissolving sodium nitrite in water to obtain a sodium nitrite aqueous solution, cooling, adding sulfanilic acid and hydrogen chloride aqueous solution, reacting in an ice water bath to prepare an aryl diazonium salt (I), dissolving sodium borohydride in water, adding aqueous solution of sodium borohydride to graphene oxide suspension, dripping aryl diazonium salt, and ultrasonically processing to obtain highly stripped sulfonated graphene. USE - Method is useful for the preparation of high-dispersion magnetic graphene nano-adsorbent, which is useful for adsorbing and removing organic contaminants including malachite green, methylene blue, methyl orange and methyl violet in water (all claimed). ADVANTAGE - The method ensures the preparation of high-dispersion magnetic graphene nano-adsorbent with high adsorption and magnetic properties, and can rapid and efficient separation of organic contaminant from water without environmental pollution. DETAILED DESCRIPTION - The method for the preparation of high-dispersion magnetic graphene nano-adsorbent involves ultrasonically dispersing 100 mg graphene oxide in 100 ml deionized water to obtain 1 mg/ml graphene oxide suspension, dissolving 72 mg sodium nitrite in 40 g water to obtain a sodium nitrite aqueous solution, cooling to 0-5 degrees C, adding 184 mg sulfanilic acid and 2 g of 1 mole/l hydrogen chloride aqueous solution, reacting in an ice water bath for 30 minutes to prepare an aryl diazonium salt of formula (I), dissolving 600-800 mg sodium borohydride in 20 ml water to obtain an aqueous solution of sodium borohydride, adjusting pH value of the graphene oxide suspension to 9-10 using 5 wt.% sodium carbonate aqueous solution, adding the aqueous solution of sodium borohydride, uniformly stirring, heating at 80 degrees C for 1-2 hours, cooling to room temperature, ultrasonic stripping for 15-30 minutes, dripping aryl diazonium salt under stirring, reacting in an ice water bath at room temperature for 2 hours, dialyzing with deionized water until the pH is 7, ultrasonically processing for 15-30 minutes to obtain highly stripped sulfonated graphene having superior water dispersibility, adding iron(II) chloride tetrahydrate and iron(III) chloride hexahydrate to 100 ml de-ionized water, where the molar ratio of iron(II) and iron(III) is 2:1, dissolving and mixing evenly, adding the mixture to the sulfonated graphene, adjusting the pH value of the mixed solution to 11 using 20-30 wt.% aqueous ammonia, adding the mixed solution to a hydrothermal reaction kettle, ultrasonically treating for 30 minutes at 100-20 degrees C, cooling to room temperature for 3-5 hours, washing by magnetic separation, vacuum drying at 60 degrees C for 24 hours to obtain a high-dispersion magnetic graphene nano-adsorbent. An INDEPENDENT CLAIM is included for application of magnetic graphene nano-adsorbent for adsorbing and removing malachite green or other organic contaminants in water, which involves adding aqueous solution containing organic pollutants to the adding magnetic graphene nano-adsorbent, ultrasonically processing for 3-5 minutes so that the magnetic graphene nano-adsorbent is uniform mixed with organic pollutants in water, allowing to stand at room temperature for 3-5 minutes, and subjecting the mixture to magnetic separation.