▎ 摘　　要

NOVELTY - Graphene oxide comprises a hydroxyl group and/or carbonyl-containing groups, in the Raman spectrum. The graphene oxide has intensity ratio (ID/IG) between the D band and the G band of the former/latter (intensity ratio) of 0.01-0.2. USE - The graphene oxide is useful for dispersion liquid (claimed). ADVANTAGE - The graphene oxide has high dispersibility and suppressed generation of structural defects. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) graphene oxide dispersion liquid comprising the above-mentioned graphene oxide and an aqueous dispersion medium; and (2) method for producing the graphene oxide, which involves subjecting suspension containing a carbon material having a graphene structure and an aqueous dispersion medium to plasma treatment in liquid or liquid surface to introduce a hydroxyl group and/or a carbonyl-containing group into graphene.