Preparation And Performance Research Of Bismuth-based Composite Materials Photocatalyst

With the rapid development of social and economic,environmental pollution has become a serious problem faced by human society.The abusing antibiotics caused a threat to humans and organisms through enrichment,and even the emergence of drug-resistant superbacteria.However,the traditional wastewater treatment technology is inability on complex macromolecular organic.Advanced oxidation technology generate strong oxidizing free groups and can efficiently degrade pollutants,which is considered great technology to remove water pollutants.Bi_3.64Mo_0.36O_6.55 is a special cubic phase crystal structure of bismuth molybdenum,which belongs to a typical Aurivillius type compound.The unique layered structure can effectively improve the photoelectric charge transfer.However,there are few reports on Bi_3.64Mo_0.36O_6.55’s pollutants degradation,due to its poor light absorption and recombination of photogenerated electron hole pairs.In this study,copper and iron elements were selected as the photo-Fenton-like reaction center.Bi_3.64Mo_0.36O_6.55 was loaded to prepare a heterogeneous photo-Fenton composite catalyst,which improve the separation efficiency of photogenerated carriers and promote the efficient degradation of antibiotics.The main research contents of this paper are as follows:1.Bi_3.64Mo_0.36O_6.55 and Cu Bi₂O₄ prepared Bi_3.64Mo_0.36O_6.55/Cu Bi₂O₄ composite,which constitutes photo-Fenton-like copper-based composite catalyst to efficient degrades pollutants.The composite material can catalyze the decomposition of H₂O₂,improve the efficiency of Cu⁺generation.The degradation of Bi_3.64Mo_0.36O_6.55/Cu Bi₂O₄ is 3.5 times than Cu Bi₂O₄,and the photo-degradation rate closed to 82.7%degradation after 30 min.Through trapping experiments and electron spin resonance,it is proved that the main free radicals in the Bi_3.64Mo_0.36O_6.55/Cu Bi₂O₄ system are·OH,·O₂^-and h⁺.Finally,discussed the effect of different p H value,hydrogen peroxide content,catalyst content and different pollution concentration on the degradation process.In addition,the system has high photo-degradation activity to degrade organic pollutants such as Rhodamine B,methyl orange and methylene blue.This study provides a new method to constructing a copper-based heterogeneous photo-Fenton-like system can effectively photo-degrade pollutants.2.Flaky structure magnetic material was prepare by strong alkaline solvothermal and high temperature calcination Ba Fe₁₂O₁₉.After loaded with nano-particles Bi_3.64Mo_0.36O_6.55,the Ba Fe₁₂O₁₉/Bi_3.64Mo_0.36O_6.55 composite material was construct a magnetically recyclable photo-Fenton-like degradation system.The composite catalyst not only activates hydrogen peroxide to generate oxidizing free radicals,but also promote the effective transfer of photo-generated electrons and improve the Fe³⁺/Fe²⁺cycle effect.The degradation of Ba Fe₁₂O₁₉/Bi_3.64Mo_0.36O_6.55-0.25 is 4.2times than Bi_3.64Mo_0.36O_6.55,and the photo-degradation rate closed to 84.5%degradation after 60 min.Ba Fe₁₂O₁₉/Bi_3.64Mo_0.36O_6.55 was separate by an external magnetic field after the photocatalytic activity reaction because of Ba Fe₁₂O₁₉’s magnetic properties.It is providing a new research idea for construct and iron-based heterogeneous Fenton-like system to magnetic degradation of antibiotics.3.MIL-88A was prepared by simple hydrothermal method and Bi_3.64Mo_0.36O_6.55nanoparticle was loade with polyvinylpyrrolidone to construct the Fe-based MOFs photo-Fenton-like degradation system.In Bi_3.64Mo_0.36O_6.55/MIL-88A composites,not only have large pore size,high adsorption and special layered structure,but also can effectively promote photogenerated charge transfer and accelerate the Fe³⁺/Fe²⁺cycling effect.The energy band structure,free radical capture experiment and ESR analysis showed that the CB electrons in Bi_3.64Mo_0.36O_6.55 could be transferred to MIL-88A.So MIL-88A has more photogenerated electrons,which could promote the Fe³⁺/Fe²⁺transformation,enhance the redeoxification ability of the material,and accelerate the system degradation of pollutants.