▎ 摘　　要

NOVELTY - Nano material comprises iron (Fe), iron nitride (Fe4N), iron(II,III)oxide (Fe3O4), reduced graphene oxide (rGO), where the micro-topography is Fe/Fe4N/Fe3O4 nano-particles attached in the rGO sheet including graphite net-shaped structure, and Fe/Fe4N/Fe3O4 nano-particle distribution is uniform. USE - The nano material is useful for preparing electromagnetic wave absorption materials (claimed). ADVANTAGE - The nano material: has high-electromagnetic wave absorption performance, reasonable design, simple process, low synthetic raw material cost, safety and environmental protection, has controllable morphology and uniform size distribution; and when it is applied to electromagnetic wave absorbing materials, which has high electromagnetic wave absorption performance in the low frequency band, and has wide wave absorption with excellent effects e.g. frequency band, meet the comprehensive requirements of modern absorbing materials, namely thin, wide, light and strong. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) preparing the nano-material, comprising (i) dissolving soluble iron salt and soluble iron salt in water under the protection of inert gas, adding ammonia water to make the pH of the system to less than or equal to 10, reacting under the condition of stirring, then washing the obtained precipitate, vacuum drying, and grinding to obtain Fe3O4 nanoparticles, and (ii) fully dispersing Fe3O4 nano-particle obtained in the step (i) in the graphene oxide water dispersion, adding the secondary phosphoric acid aqueous solution and urea, fully dispersing and mixing uniformly, soaking at room temperature, then pouring out the supernatant, freezing and drying, and calcining under the protection of inert gas; and (2) use method of nanomaterials with high electromagnetic wave absorption properties, comprising using nanomaterials to prepare electromagnetic wave absorption coatings, and specifically including uniformly mixing and dispersing resin, silane coupling agent, Fe/Fe4N/Fe3O4-rGO nanomaterials and water to obtain electromagnetic wave absorption coating.