▎ 摘　　要

NOVELTY - Preparation of graphene oxide hydrogel involves annealing graphene oxide dispersion in a sealed container, or mixing graphene oxide dispersion and acid solution, adjusting pH to 1-4, and carrying out sol-gel phase transition reaction. USE - Preparation of graphene oxide hydrogel used for manufacture of reduced graphene film and graphene oxide fibers (all claimed). ADVANTAGE - The method efficiently and economically provides graphene oxide hydrogel with high productivity, by simple method. The reduced graphene film or graphene oxide fibers manufactured using graphene oxide hydrogel has high mechanical property, electrical conductivity, heat conductivity and toughness. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) manufacture of reduced graphene film using graphene oxide hydrogel; and (2) manufacture of graphene oxide fibers using graphene oxide hydrogel.