▎ 摘　　要

NOVELTY - A graphene/triiron tetroxide composite material comprises reduced graphene oxide and triiron tetroxide nanoparticles, and includes a three-dimensional porous structure. USE - Graphene/triiron tetroxide composite material is used for forming electromagnetic wave shielding material or device, or electromagnetic wave absorbing material or device (all claimed). DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of graphene/triiron tetroxide composite material, which involves mixing graphene oxide with a metal organic compound of iron in an organic solvent to form a mixed solution, performing solvothermal reaction of the mixed solution to form a three-dimensional graphene/triiron tetroxide gel-like material, removing the organic solvent from the gel-like material, and reducing the obtained material.