▎ 摘　　要

NOVELTY - Preparation of a nickel nanoparticles/graphene electromagnetic wave-absorbing material involves adding borohydride to a deionized aqueous solution under magnetic stirring to obtain a borohydride solution, slowly adding concentrated aqueous ammonia to the borohydride solution, uniformly dispersing the mixed solution to obtain an ammonia/borohydride mixture, adding a nickel ion source reagent/graphene oxide mixed solution to a constant temperature magnetic stirring water bath, continuously stirring at a rate of 500-1500 rpm under constant temperature, titrating the ammonia/borohydride mixed solution, dripping to the nickel ion source reagent/graphene oxide mixed solution at a molar ratio of nickel ion and borohydride of 1:(1-3) to carry out a titration reduction reaction to obtain a reaction product, cleaning the reaction product, and drying to obtain a nickel nanoparticles/graphene nanocomposite preliminary reaction product, and heat-treating the preliminary reaction product. USE - Preparation of a nickel nanoparticles/graphene electromagnetic wave-absorbing material used as electromagnetic shielding or loss material for electromagnetic protection and microwave stealth. ADVANTAGE - The prepared electromagnetic wave-absorbing composite material has high wave absorbing intensity, effective wave-absorbing frequency band width, and thin thickness and light, and is obtained by simple and low cost method. In the preparation of composite material, the synthesis reaction has mild reaction condition, short reaction time, no high temperature heating and no high reaction temperature. The graphene wrinkle effectively inhibits the agglomeration of nickel nanoparticles and promotes the dielectric and magnetic synergistic loss of electromagnetic waves. The composite material has small density, little addition amount, simple preparation technique and excellent wave-absorbing characteristics. DETAILED DESCRIPTION - Preparation of a nickel nanoparticles/graphene electromagnetic wave-absorbing material involves weighing and adding 0.2-0.8 g/L graphene oxide powder to deionized water, ultrasonically dispersing for 50-70 minutes to obtain a uniform graphene oxide dispersion, weighing and adding an appropriate amount of nickel ion source reagent to the graphene oxide dispersion, magnetically stirring to obtain 0.05-0.3 mol/L mixed solution of nickel ion source reagent/graphene oxide, weighing a certain amount of borohydride and adding to a deionized aqueous solution under magnetic stirring to obtain a borohydride solution, slowly adding concentrated aqueous ammonia to the borohydride solution, uniformly dispersing the mixed solution to obtain an ammonia/borohydride mixture, adding the nickel ion source reagent/graphene oxide mixed solution to a constant temperature magnetic stirring water bath, continuously stirring at a rate of 500-1500 rpm under constant temperature, titrating the ammonia/borohydride mixed solution, dripping to the nickel ion source reagent/graphene oxide mixed solution at a molar ratio of nickel ion and borohydride of 1:(1-3) to carry out a titration reduction reaction to obtain a reaction product, cleaning the reaction product, and drying to obtain a nickel nanoparticles/graphene nanocomposite preliminary reaction product, and heat-treating the preliminary reaction product by adding the preliminary reaction product to a tube furnace, heating to 600-700°C at a rate of 2-4°C/minute under the condition of passing argon for 1-3 hours, and continually passing argon to cool to room temperature. The volume ratio of concentrated aqueous ammonia and borohydride solution is (2-4):3.