▎ 摘　　要

NOVELTY - Preparing graphene based ferroferric oxide nano composite material comprises (i) dissolving soluble ferric salt in deionized water, and stirring uniformly to obtain ferric salt solution; (ii) adding graphene oxide into ferric salt solution, and uniformly dispersing graphene oxide in ferric salt solution to obtain a mixed solution; (iii) dripping a reducing agent into the mixed solution, stirring at 60-150 degrees C for 30-240 minutes, and adding the reducing agent and ferric salt; and (iv) washing the reaction product obtained in the step (iii) with deionized water, and drying in vacuum. USE - The composite material is used as sewage treatment agent. ADVANTAGE - The method: is simple, low in cost, and is suitable for industrial production; can load the graphene particle on a uniform diameter particle, and can control the appearance of ferroferric oxide nano particle. The graphene ferroferric oxide nano composite material has large specific surface area, high saturation magnetic induction intensity, and heavy metal ion adsorption capacity. DETAILED DESCRIPTION - Preparing graphene based ferroferric oxide nano composite material comprises (i) dissolving soluble ferric salt in deionized water, and stirring uniformly to obtain ferric salt solution, where the concentration is 0.01-1 mol/l; (ii) adding graphene oxide into ferric salt solution, and uniformly dispersing graphene oxide in ferric salt solution to obtain a mixed solution, where the mass ratio of the graphene oxide and ferric salt is 1:100-1:1000; (iii) dripping a reducing agent into the mixed solution, stirring at 60-150 degrees C for 30-240 minutes, and adding the reducing agent and ferric salt; and (iv) washing the reaction product obtained in the step (iii) with deionized water, and drying in vacuum to obtain the graphene based ferroferric oxide nano composite material.