Application Of Superconducting Material YBCO In Catalytic Degradation Of Organic Dyes And Photocatalysis

Environmental pollution and the lack of clean energy have become one of the most serious problems in the world.In particular,The serious water pollution caused by human activities has led to more and more serious water shortage.Traditional physical techniques?activated carbon adsorption,ultrafiltration,reverse osmosis,chemical coagulation,ion exchange on synthetic adsorption resins,etc.?can effectively transfer organic contaminants from the aqueous phase to another phase.This physical treatment does not eliminate contaminants and sometimes causes secondary pollution.Moreover,the production cost of the regenerable adsorbent material is high.Therefore,the complete decomposition of organic matter is a very meaningful study.Advanced oxidation processes?AOPs?can degrade water pollution problems.The precondition for the occurrence of AOPs is the presence of highly active substances such as hydroxyl radicals?·OH?.Fenton reaction is one of the most rapid,cost-effective and advanced oxidation methods for treating non-biodegradable organic pollutants in wastewater.During the reaction process,the oxidant dissociates and forms highly active·OH,·OH can erode and destroy organic pollutants,and mineralize the organic compound dyes in the wastewater into harmless compounds such as CO₂,H₂O and inorganic salts.The use of solar photocatalysis to photodecompose organic pollutants in water is a new technology developed in the past two decades.·OH is an important active intermediate both in the traditional treatment of pollutants in water and in the new photocatalytic process.Its production and transformation process as well as its concentration have an important influence on the treatment of pollutants in water or the process of photolysis.YBa₂Cu₃O_7-??YBCO?is a high temperature superconducting material,it has excellent electron transport properties.In particular,it was found that this material had the properties of promoting the decomposition of H₂O₂ at room temperature.In the equilibrium of the formation reaction of H₂O₂,·OH is an important active intermediate.Therefore,based on the superconducting material YBCO,We investigated the effect of promoting the decomposition of H₂O₂ on organic pollutant degradation and photocatalysis.In the first part of the paper,we studied the application of superconducting material YBCO in catalytic degradation of organic pollutants.Superconducting material YBa₂Cu₃O_7-??YBCO?is a high-temperature superconductor with unique structural defects,variable stoichiometric,mixed valence copper ions,and high surface oxygen content,which make it has the potential of catalytic oxidation.This paper studies the application of YBCO in the catalytic degradation of organic pollutants.When YBCO and H₂O₂ exist simultaneously,YBCO can rapidly catalyze H₂O₂ aqueous solution to generate large amount of·OH.·OH,as a strong oxidant,can degrade the organic dye methylene blue?MB?in the solution.In this study,the superconducting material YBCO was synthesized by solid phase sintering method,then we explored the optimal conditions for degradation of MB.In the second part of the paper,we studied the effect of superconducting material YBCO on photocatalytic oxygen production.WO₃ has a solar absorption range of about 12%and good hole diffusion properties,so it is widely used in photocatalytic oxygen production and is a common photocatalytic oxygen production catalyst.In this study,WO₃ was used as the carrier and YBCO was supported on WO₃.We synthesized the composite catalyst YBCO/WO₃,and based on the special properties of YBCO surface,we explored the superconducting materials in promoting photocatalytic oxygen production performance.In the third part of the thesis,based on the preliminary work,we further studied the effect of superconducting material YBCO on photocatalytic hydrogen production.In the process of WO₂-Na_xWO₃ photolysis water,due to the generation of peroxide during the reaction,O₂ release is suppressed.YBCO has the ability to catalyze the oxidation of peroxide.By combining YBCO with WO₂-Na_xWO₃,we explored by promoting the decomposition of peroxide to improve the hydrogen production efficiency.