▎ 摘　　要

NOVELTY - Preparation of manganese ferrite nanoparticles-graphene composite comprises oxidizing graphite with potassium permanganate to obtain graphene oxide, ultrasonically processing, diluting with water to obtain homogenous manganese-containing graphene oxide solution, adding hydrogen peroxide to reduce permanganate ions into divalent manganese ions, adding ferric and manganous salts, and uniformly stirring; adjusting pH to 8-13 with alkaline aqueous solution; and adding reducing agent and heating to 70-99 degrees C, maintaining temperature and stirring for 0.5-24 hours, magnetically separating, and drying. USE - Method for preparing manganese ferrite nanoparticles-graphene composite used as electromagnetic shielding material (claimed). ADVANTAGE - The method is simple and environmentally friendly, and has low cost. The obtained composite has specific surface area of 5-100 m2/g and electromagnetic shielding efficiency of 15-90 dB at 5 kHz to 18 GHz.