▎ 摘　　要

NOVELTY - Producing graphene oxide having increased amount of oxygen functional groups, comprises (a) adding iron compound and oxidizing agent in weight ratio of 0.01-3:0.1-10 into graphene oxide, and introducing oxygen functional groups by heating, and (b) purifying graphene oxide with introduced oxygen functional group. USE - The graphene oxide is useful for coating electrode (claimed). ADVANTAGE - The method is simple to process. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for ozonated graphene oxide produced by mixing iron compound and oxidizing agent with graphene oxide at 25 degrees C for 10-14 hours.