▎ 摘　　要

NOVELTY - Double rare earth oxide graphene composite photocatalytic treatment of dye waste water comprises mixing graphene oxide powder, yttrium nitrate hexahydrate and cerium nitrate hexahydrate, adding ethanol, dispersing, adding polyvinylpyrrolidone, reacting, centrifugally separating, washing with ethanol and deionized water, drying to obtain yttrium oxide/cerium oxide/graphene composite product, adding into waste water, placing into a photocatalytic reactor, irradiating with mercury lamp, photocatalysis, filtering, determining cerium concentration and calculating photocatalytic removal rate. USE - The method is useful for double rare earth oxide graphene composite photocatalytic treatment of dye waste water (claimed). ADVANTAGE - The method ensures high dye waste water removal rate in a cost effective manner. DETAILED DESCRIPTION - Double rare earth oxide graphene composite photocatalytic treatment of dye waste water comprises (a) taking 2 g graphite powder and 1-2 g sodium nitrate mixture, adding 30-40 ml concentrated sulfuric acid (98%) and stirring in an ice bath for 2 hours, (b) adding 3-5 g potassium permanganate and stirring uniformly, (c) placing the mixture in 35 degrees C water bath, stirring for 2-3 hours, (d) adding 30-50 ml deionized water after removing from the water bath, heating and maintaining boiling state, continuously stirring for 2-3 hours, (e) cooling to room temperature and adding 100-300 ml deionized water, adding 50-150 ml hydrogen peroxide, and stirring the solid-liquid mixture, (f) washing the solid-liquid mixture with 3-5% hydrochloric acid, for 3-5 times, washing with deionized water for 3-5 times, until the pH of the solid liquid mixture is 6.8, (g) centrifugally separating the solid-liquid mixture to remove moisture to obtain graphene oxide solid, (h) drying at 50-80 degrees C for 15-18 hours, and grinding to obtain graphene oxide powder, (i) adding 5-10 ml deionized water and 10-40 ml ethanol, mixing uniformly, taking 12 mg graphene oxide powder, yttrium nitrate hexahydrate and cerium nitrate hexahydrate, uniformly mixing, adding ethanol solution after stirring, uniformly dispersing until yttrium hexahydrate nitrate and cerium nitrate hexahydrate are completely dissolved, adding 0.1-0.5 g polyvinylpyrrolidone, and stirring to dissolve, (j) transferring the mixture into a reaction kettle, and reacting at 160-180 degrees C for 16-20 hours, (k) centrifugally separating to remove moisture, washing with ethanol and removing un-reacted polyvinylpyrrolidone, washing with deionized water to remove un-reacted inorganic ions, until the pH of the solution is more than 6.8, drying the washed reaction product in a drying tank at 60-80 degrees C for 5-8 hours to obtain yttrium oxide/cerium oxide/graphene composite finished product, (l) taking 5-10 mg double rare earth oxide graphene composite product into 40 ml dye-containing waste water, where the initial cobalt concentration in the dye-containing waste water is 20-30 mg and the pH is 3.03-6.3, (m) adding the dye-containing waste water into a glass container and sealing, (n) placing the glass container in dark in a photocatalytic reactor, stirring for 30-60 minutes, and controlling the temperature at 20 degrees C, (o) stirring, irradiating the solid-liquid mixture with a mercury lamp for 35-120 minutes with mercury lamp power of 300 W, (p) performing photocatalysis, extracting 5 ml dye-containing waste water, and filtering, (q) taking 2 ml supernatant, using UV-spectrophotometry to determine cerium concentration in the dye after treatment, and (r) calculating photocatalytic removal rate using the formula (cobalt-cerium)/cobaltx 100%.