▎ 摘　　要

NOVELTY - Preparation of graphene oxide-cobalt nano-composite catalyst, involves obtaining graphene oxide using graphite powder, concentrated sulfuric acid, potassium permanganate, hydrogen peroxide and deionized water, dissolving cobalt(II) sulfate heptahydrate in deionized water, then adding graphene oxide, ultrasonically dispersing, adding hydrazine hydrate, then ultrasonically dispersing, transferring a solution to a hydrothermal reaction vessel at 180 degrees C after the completion of ultrasonic dispersion treatment, cooling to room temperature, filtering, collecting precipitate and drying. USE - Preparation of graphene oxide-cobalt nano-composite catalyst used in catalytic degradation of rhodamine B dye (claimed). ADVANTAGE - The graphene oxide-cobalt nano-composite catalyst cannot be dissolved in neutral and alkaline environments, and has excellent crystallization property, catalytic performance and excellent visible-light responsiveness. The graphene oxide-cobalt nano-composite catalyst can efficiently catalyze ozone to degrade rhodamine B dye wastewater with a concentration of not smaller than 50 mg/L under the sunshine, and has excellent stability, high efficiency, and is low in price and free from toxicity. DETAILED DESCRIPTION - Preparation of graphene oxide-cobalt nano-composite catalyst, involves using natural graphite powder as the raw material for preparing graphene oxide, adding 1 g graphite powder with 23 mL of 98 %mass concentrated sulfuric acid in an ice bath, stirring for 10 minutes, adding 3 g potassium permanganate, continually stirring for 1 hour, transferring the resulting dark green mixture to a water bath, and continually stirring for 30 degrees C for 1 hour, dripping 46 mL deionized water in the water bath at 96 degrees C, then stirring for 30 minutes, and finally adding 10 mL hydrogen peroxide and 140 mL deionized water to terminate the reaction, centrifuging the resulting mixture at 4000 rpm for 10 minutes, using hydrochloric acid having mass concentration of 5% and washing three times with ethanol, collecting the resulting precipitate and drying at 60 degrees C for 12 hours to obtain graphene oxide, dissolving 0.0313-0.0399 g cobalt(II) sulfate heptahydrate in 40 mL deionized water, then adding 0.1 g graphene oxide, ultrasonically dispersing for 1 hour, then adding 0.1 mL hydrazine hydrate, then again ultrasonically dispersing for 5 minutes, transferring a solution to a hydrothermal reaction vessel at 180 degrees C for 10 hours after the completion of ultrasonic dispersion treatment, cooling to room temperature, filtering, collecting the precipitate, drying at 60 degrees C for 6 hours to obtain graphene oxide-cobalt nano-composite catalyst with a cobalt mass percentage of 5-6%.