▎ 摘　　要

NOVELTY - Manufacture of three-dimensional graphene involves providing a core-shell composite in which core is surrounded by graphene or graphene derivative as shell material, and etching using an etching agent. USE - Manufacture of three-dimensional graphene used for manufacturing of reduced graphene used in manufacture of three-dimensional porous mesh structure (all claimed) used for structure material for active electrode used in energy conversion and switching device. ADVANTAGE - The method provides three-dimensional graphene having excellent dispersion stability and electroconductivity. The three-dimensional graphene enables efficient manufacture of reduced graphene with high productivity. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) core-shell composite, which comprises shell made of graphene oxide, surrounding the core containing polycrystalline iron oxide and/or polycrystalline metal oxide; (2) manufacture of three-dimensional porous mesh structure; and (3) manufacture of reduced graphene.