▎ 摘　　要

NOVELTY - Three-dimensional graphene foam, obtained by firstly mixing graphene oxide slurry, reducing agent and pore-forming agent, performing hydrothermal reaction to the resulting mixed solution, and vacuum-drying the resulting graphene gel, where the pore-forming agent includes pore-forming agent capable of sublimation under the temperature conditions of hydrothermal reaction and vacuum drying. USE - The three-dimensional graphene foam is useful as wave absorbing agent of wave absorbing material (claimed). ADVANTAGE - The three-dimensional graphene foam has low density, high dielectric properties (conductivity) and adjustable internal pore structure, and has the advantage of obtaining excellent wave-absorbing performance with an ultra-low addition amount. The method has simple process and low cost. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: preparing three-dimensional graphene foam; and wave-absorbing material.