▎ 摘　　要

NOVELTY - Graphene composite material comprises reduced graphene oxide. The reduced graphene oxide is a layered reduced graphene oxide, which has a sheet structure. The elementary carbon is coated with a hollow silicon dioxide ball, forming a carbon-coated hollow silicon dioxide ball. The carbon-coated hollow silicon dioxide is connected with the laminated structure of the layered reduced graphene oxide. USE - The material is useful in thermally conductive and/or electrical shielding materials (claimed). ADVANTAGE - The material has high heat conducting coefficient, high electromagnetic absorption and low electromagnetic reflection. The method is simple. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing the graphene composite material, comprising adding dopamine solution to the hollow silica sphere dispersion liquid, and stirring to prepare a silica-polydopamine solution, (ii) adding graphene oxide aqueous solution to the silica-polydopamine solution, adding acid to adjust the pH to less than or equal to 2.5, stirring and filtering with suction to obtain a filter cake, and (iii) calcining filter cake in an inert environment.