▎ 摘　　要

NOVELTY - A cobalt selenide/nitrogen and phosphorus co-doped graphene composite material is prepared by heating selenium powder solution, stirring to obtain reaction liquid I, heating triphenylphosphine solution, stirring to obtain reaction liquid II, heating nitrogen-doped graphene solution, ultrasonically processing to obtain reaction liquid III, heating cobalt acetylacetone solution, stirring to obtain reaction liquid IV, mixing reaction liquids I, II, III and IV, stirring to obtain reaction liquid V, transferring into hydrothermal reaction kettle, and reacting to obtain reaction product I; and cooling, centrifuging and separating, removing upper layer clear liquid, collecting lower layer solid substance, centrifugally cleaning collected lower layer solid substance using heptane anhydrous ethanol solution, and vacuum drying cleaned solid substance. USE - The method is used for preparing cobalt selenide/nitrogen and phosphorus co-doped graphene composite material as electromagnetic wave absorbing material (claimed). ADVANTAGE - The method solves nitrogen preparation, gradually release of harmful gas in phosphorus-doped graphene load nanomaterial, expensive raw material, high preparation cost, bad nano-particle load and not uniform load. DETAILED DESCRIPTION - A cobalt selenide/nitrogen and phosphorus co-doped graphene composite material is prepared by: (A) dissolving selenium powder in liquid oleylamine to obtain selenium powder solution, dissolving triphenylphosphine in liquid oleylamine to obtain triphenylphosphine solution, dispersing nitrogen-doped graphene into anhydrous ethanol to obtain nitrogen-doped graphene solution, and dispersing cobalt acetylacetonate (II) into anhydrous ethanol to obtain cobalt acetylacetonate solution; (B) heating selenium powder solution to 200-250 degrees C, stirring at 200-250 degrees C to obtain reaction liquid I, heating triphenylphosphine solution to 100-150 degrees C, stirring at 100-150 degrees C to obtain reaction liquid II, heating nitrogen-doped graphene solution to 40-60 degrees C, ultrasonically processing at 40-60 degrees C to obtain reaction liquid III, heating cobalt acetylacetone solution to 50-100 degrees C, stirring at 50-100 degrees C to obtain reaction liquid IV, mixing reaction liquids I, II, III and IV, stirring to 40-60 degrees C to obtain reaction liquid V, transferring into hydrothermal reaction kettle, and reacting to 180-240 degrees C for 120-240 minutes to obtain reaction product I; and (C) cooling to room temperature, centrifuging and separating, removing upper layer clear liquid, collecting lower layer solid substance, centrifugally cleaning collected lower layer solid substance using heptane anhydrous ethanol solution at 50-60 degrees C, and vacuum drying cleaned solid substance.