▎ 摘　　要

NOVELTY - Cobaltous oxide nano-graphene composite material comprises graphene sheet, and the cobaltous oxide nanocrystal dispersed on the graphene, where the grain diameter of the cobaltous oxide nanocrystal is 5-8 nm, average grain diameter is 6 nm. USE - The composite material is used in the electromagnetic wave absorbing field, and the catalysis field (claimed). ADVANTAGE - The material has no agglomeration phenomenon, has good magnetic performance, improves the electromagnetic wave absorption performance and catalytic performance. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing cobaltous oxide nano-graphene composite material comprising adding the graphite oxide in oleylamine and carrying out dispersion treatment to obtain mixed solution, mixing the acetylacetone cobalt and octadecylamine, adding to the mixed solution, under the state of stirring, heating the mixed liquid to 120-140 degrees C, keeping the temperature for more than 30 minutes, then continuously under the stirring state, heating to 290-310 degrees C, preserving heat for more than 2 hours, adding organic solvent in the reaction, separating the reaction product, washing reaction product and drying, where the acetylacetone cobalt and graphite oxide is 1 mol: (20-40) g, the mass ratio of graphite oxide and octadecylamine is 1:(12.5-50), the ratio of oleylamine to the graphite oxide is 1 l: 1 g.