▎ 摘　　要

NOVELTY - Preparing cobalt manganate/N-doped graphene composite catalyst comprises e.g. choosing cobalt nitrate, manganese nitrate, citric acid, ultrapure water, N-doped graphene, and ethanol as raw materials, preparing dry cobalt oxide, calcining, dispersing cobalt manganate and N-doped graphene in ethanol, ultrasonically processing, mixing uniformly, suction filtrating, water washing, and finally vacuum drying, and placing cobalt manganate/N-doped graphene composite in tube furnace under inert gas atmosphere, controlling temperature at 400-800 degrees C for calcination, and controlling heating rate at 10-15 degrees C/minutes, and constant temperature for 60-180 minutes, cooling mixture to room temperature under inert atmosphere to obtain activated persulfate-cobalt-manganese/N-doped graphene composite catalyst. USE - The cobalt manganate/N-doped graphene composite catalyst is useful in removing water contaminants, i.e. preservative, paraben ethyl ester (EP), sunscreen 2-phenylbenzimidazole-5-sulfonic acid (PBSA), rhodamine B dye and/or methyl orange (claimed). ADVANTAGE - The method: is economical, and suitable for industrial production. DETAILED DESCRIPTION - Preparing cobalt manganate/N-doped graphene composite catalyst comprises (i) choosing cobalt nitrate, manganese nitrate, citric acid, ultrapure water, N-doped graphene, and ethanol as raw materials, (ii) preparing dry cobalt oxide by gel method, and then controlling at 10 degrees C/minutes in muffle furnace at 500 degrees C, calcining for 2 hours, to obtain cobalt manganate, (iii) dispersing cobalt manganate and N-doped graphene obtained in step (ii) in ethanol at mass ratio of 1:1, ultrasonically processing for 30 minutes, mixing uniformly, then suction filtrating, water washing, and finally vacuum drying at 50-60 degrees C for 12-24 hours to obtain dried cobalt manganate/N-doped graphene composite, and (iv) placing cobalt manganate/N-doped graphene composite in tube furnace under inert gas atmosphere, controlling temperature at 400-800 degrees C for calcination, and controlling heating rate at 10-15 degrees C/minutes, and constant temperature for 60-180 minutes, cooling mixture to room temperature under inert atmosphere to obtain activated persulfate-cobalt-manganese/N-doped graphene composite catalyst. An INDEPENDENT CLAIM is also included for use method of cobalt manganate/N-doped graphene composite catalyst in removing water pollution, comprising adding prepared cobalt manganate/N-doped graphene composite catalyst to sewage to be treated, adding potassium hydrogen persulfate, and stirring/oscillating at normal temperature.