Preparation And Photocatalytic Properties Of Magnetic Nanoscale Photocatalyst Co²⁺-Fe₃O₄/Bi₂WO₆

Printing and dyeing wastewater is considered to be one of the most difficult industrial wastewater with a large number of organic dyes and auxiliaries.Dye in printing and dyeing wastewater is a threat to environmental and biological health.The efficient treatment of printing and dyeing wastewater are of great significance for the long-term development.Optical semiconductor catalysts are widely used in the degradation of organic mixtures,and the related research reports are common.However,in the actual process,the tiny particle size of the photocatalyst makes it difficult to separate from the water and can hardly be recycled.Magnetic nanocatalysts can use magnetic efficiency to recover the catalyst.Different magnetic loading forms will affect the catalytic activity of photocatalysts to varying degrees..So this paper attempts to immobilize Bi₂WO₆ on the surface of Fe₃O₄,and the preparation conditions were optimized.The crystal structure,crystallinity,magnetic properties,surface properties and morphology were analyzed and controlled by XRD,SQUID,BET,SEM,FT-IR,XPS.Rh B is used as the target substrate to evaluate the photocatalytic activity,and the details are as follows:1.The samples of Fe₃O₄,Fe₃O₄/Bi₂WO₆ and Bi₂WO₆ were prepared by hydrothermal method.FT-IR shows the surface of the three were all covered with PVP.The Fe₃O₄/Bi₂WO₆ sample is superparamagnetic.When the Fe₃O₄ compound is 0.04 g,the saturation magnetization of the composite catalyst is 4.250emu?T=300K?.G-1.The compound amount of Fe₃O₄ in the composite catalyst is directly proportional to the magnetic strength,and is inversely proportional to the photocatalytic activity.After 4 times reuse,the percent recovery of Fe₃O₄?0.04g?/Bi₂WO₆ composite catalyst is 94.6%,and shows good stability.2.In order to increase the photocatalytic activity of Fe₃O₄?0.04g?/Bi₂WO₆,the doping of Co²⁺ metal ions was made,and the amount of Co²⁺ and the precursor solution p H were optimized.In the range of doping in the experiment,the amount of Co²⁺ has a slight influence on the band gap of Fe₃O₄?0.04g?/Bi₂WO₆.The doping process makes more active sites on the surface of the crystal and enhances the photocatalytic activity of Fe₃O₄?0.04g?/Bi₂WO₆.The p H of precursor liquid has significantly affects photocatalytic efficiency of Fe₃O₄?0.04g?/Bi₂WO₆,and near neutral environment is more conducive to the preparation of?1mol%?Co²⁺-Fe₃O₄?0.04g?/Bi₂WO₆ with high photocatalytic efficiency.3.The reaction conditions of?1mol%?Co²⁺-Fe₃O₄?0.04g?/Bi₂WO₆ degradation of Rh B were optimized.The best reaction conditions is that the initial concentration of Rh B was 20mg/L,Co²⁺-Fe₃O₄?0.04g?catalyst amount was 0.1mol%,reaction p H was initial.