▎ 摘　　要

NOVELTY - Cobalt oxide nano-crystal-graphene composite material is claimed, where graphene in the form sheet and cobalt oxide nano-crystal is dispersed on graphene. USE - The composite material is useful in catalytic field (claimed). ADVANTAGE - The composite material has good absorption properties and magnetic properties. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing cobalt oxide nano-crystal-graphene composite material comprising dispersing graphite oxide in N-methyl pyrrolidone to obtain mixed solution, and adding cobalt acetylacetonate and octadecyl amine to mixed solution, heating the mixed solution to 120-140 degrees C with stirring, insulating for 30 minutes or more, then continue heating with stirring to 190-202 degrees C, insulating for 2 hours or more, quenching reaction by adding organic solvent, separating reaction product, washing and drying, where mass ratio of cobalt acetylacetonate to graphite oxide is 1 mol:20-40 g, mass ratio of graphite oxide to octadecylamine is 1:12.5-50, and mass ratio of N-methyl pyrrolidone to graphite oxide is 1 L:1 g.