▎ 摘　　要

NOVELTY - Recoverable magnetic composite graphene-based metal catalyst is prepared by adding 0.2-2 g graphite and 0.2-2 g sodium nitrate into 9.2-92 mL concentrated sulfuric acid, adding solution with 1.2-12 g potassium permanganate and water, stirring at 90-95 degrees C for 30-60 minutes, adding hydrogen peroxide solution, filtering, and washing obtained solid with water to obtain graphite oxide; dispersing graphite oxide in ethylene glycol, adding metal salt and noble metal compound into graphite solution, and performing microwave irradiation for 1-l0 minutes. USE - Method of preparing recoverable magnetic composite graphene-based metal catalyst used in catalytic reduction of nitro compound including p-nitrophenol or p-nitroaniline (claimed). ADVANTAGE - The method has simple operation and low cost, and is green and environment-friendly. The obtained catalyst product has high catalytic efficiency and activity and good stability, and is easy to separate and recovered. DETAILED DESCRIPTION - Preparation of recoverable magnetic composite graphene-based metal catalyst comprises: (A) adding 0.2-2 g graphite and 0.2-2 g sodium nitrate into 9.2-92 mL of 95-98 wt.% concentrated sulfuric acid, stirring obtained solution for 1-5 hours at 0 degrees C to 4 degrees C, then adding solution with 1.2-12 g potassium permanganate and stirring at 35-40 degrees C for 1-2 hours; (B) adding 16-160 mL water into the solution, stirring at 90-95 degrees C for 30-60 minutes, adding 40-400 mL water and 1.2-12 ml of 30 wt.% hydrogen peroxide solution, then filtering, and washing obtained solid with water until pH value of solution is 6-7 to obtain graphite oxide; (C) dispersing graphite oxide in ethylene glycol for 4-8 hours to prepare 1-2 mg/mL solution; (D) taking 12.5-25 mL of the graphite solution, adding 0.055-0.22 g metal salt, ultrasonically treating for 1-10 minutes, adding 1.5-3 mL of 5-10 M sodium hydroxide aqueous solution, then adding 8-20 mg noble metal compound, ultrasonically treating for 1-10 minutes and performing microwave irradiation for 1-l0 minutes; and (E) washing the product with water and ethanol, respectively, and drying to obtain the recoverable magnetic composite graphene-based metal catalyst. An INDEPENDENT CLAIM is included for catalytic reduction of nitro compounds, comprising ultrasonically dispersing magnetic composite graphene-based metal catalyst into water to prepare 1-4 mg/mL dispersion liquid; adding 1-5 ml water into 10-50 mu L of 5-10 mM nitro compound aqueous solution, and then adding 10-50 mu L of 0.5-2 M sodium borohydride aqueous solution; and adding 10-50 mu L water dispersion liquid into the mixed solution to realize catalytic reduction of nitro compound.