▎ 摘　　要

NOVELTY - Preparing photocatalyst comprises preparing zinc iron oxide magnetic material by dissolving zinc salt and iron salt in absolute ethyl alcohol, reacting, separating, washing, drying, preparing magnetic material core by dispersing magnetic material and zinc nitrate hexahydrate or zinc sulfate heptahydrate in ethyl alcohol, ultrasonically dispersing, reacting with potassium hydroxide solution, precipitating, washing, magnetically separating, ultrasonically dispersing core and reduced graphene oxide in distilled water, reacting with aqueous ammonia and hydrazine hydrate, washing, and drying. USE - The photocatalyst is useful for magnetic control recovery of visible light (claimed). ADVANTAGE - The method produces methylene blue (MB) under visible light catalytic degradation for 120 minutes with MB residual rate of 26.7-41.2%, and can be separated by magnetic field. DETAILED DESCRIPTION - Preparing photocatalyst comprises (a) preparing zinc iron oxide magnetic material by dissolving zinc salt and iron salt in absolute ethyl alcohol in a molar ratio of 1:2, where the ratio of material to liquid is 1-3 (g/ml), stirring at room temperature for 5-12 hours, adjusting the pH to 9-10 with sodium hydroxide solution, stirring at room temperature, transferring to a polytetrafluoroethylene coated hydrothermal kettle of 90-250 degrees C, reacting for at least 5 hours, naturally cooling to room temperature, separating by magnet, washing with distilled water, drying under vacuum at 60 degrees C for 24 hours, (b) preparing magnetic material core by magnetic control separation of core-shell catalyst zinc iron oxide/zinc oxide by dispersing magnetic material and hexahydrate zinc nitrate or zinc sulfate heptahydrate in absolute ethyl alcohol in a molar ratio of 1:0.1-3, where the ratio of material to liquid is 2.5-3.5 (g/ml), ultrasonically dispersing for 0.1-5 hours, and transferring into a flask, adding ethanol solution of potassium hydroxide (25 mol/l), reacting for more than 9 minutes in a water bath of 25-95 degrees C, cooling to room temperature, precipitating by magnet separation, alternately washing with distilled water and absolute ethyl alcohol for 5 times, drying under vacuum at 60 degrees C for 24 hours, and (c) magnetically separating the prepared photo-catalyst with visible light response zinc iron oxide/zinc oxide-reduced graphene oxide by dispersing zinc iron oxide/zinc oxide core-shell photocatalyst and reduced graphene oxide in distilled water in a weight ratio of 100:0.15-4, where the material to liquid ratio is 1.1-1.2 (g/ml), ultrasonically processing for 10 minutes, electrically stirring for 24 hours, adding aqueous ammonia to adjust the pH of the reaction system to 9-10, adding hydrazine hydrate (0.49-3.88 ml), reacting for 1 hour at 95 degrees C, washing with distilled water, and vacuum drying at 40 degrees C for 48 hours.