锆酸铋光催化剂的制备及可见光催化降解有机污染物的研究

To consider the genuine need for clean, safe drinking water and solve the more and more serious pollution of refractory organic pollutants, the new method of photocatalytic oxidation is put forward in this project. For developing photo catalytic materials with high quantum efficiency and wide spectral response, the novel semiconductor bismuth zirconate will be developed as efficient visible-light-responsive photocatalysts, its nanotube structure can be formed by template synthesis. And on this basis we load the metal nanoparticles on the surface of bismuth zirconate to form visible-light-driven plasmonic photocatalysts. The green environment-friendly preparation method of bismuth zirconate will be developed, and the migration path of photogenerated charge carriers will be ascertained by surface analysis techniques and photoelectrochemical approach, combining with the analysis of photocatalytic process, thus the photocatalytic mechanism of bismuth zirconate can be revealed, and the the coupling mechanism between the photo catalytic activity of bismuth zirconate and the surface plasmon resonance of the metal nanoparticles will be illuminated. Meanwhile, we will regulate and control the component ratio, particle size, morphology and surface structure to optimize nanocomposite materials with the most optimal photo catalytic activity. And on this basis, we research the photocatalytic degradation of phenol and methyl orange, including the adsorption and degradation mechanisms on these materials, the photocatalysis degradation reaction kinetics and key controlling factors, and a photocatalysis reaction system for degradation of water pollutants under visible light irradiation will be established. In a word, our research can offer an environmentally friendly method for eliminating organic pollutants in water, and is significant in ensuring safety of drinking water and protecting the environment and health of people.

从我国饮用水安全需求出发，围绕光催化技术去除水体难降解有机污染物问题，开发量子效率高、宽谱响应的光催化材料，本课题利用模板材料的定向作用制备锆酸铋纳米管，并将粒径可控的金属纳米粒子沉积在锆酸铋表面构筑等离子体光催化剂。研究新型铋系材料锆酸铋的绿色制备技术，采用表面分析技术和光电化学方法，结合光催化降解历程分析，探明光生电子的迁移途径，揭示锆酸铋光催化作用机理，阐明氧化物的光催化作用与金属纳米粒子的表面等离子体效应的耦合机制。调控材料组分配比和粒径形貌，优化纳米复合结构的光催化降解性能，以苯酚和甲基橙为降解对象，研究它们在新型光催化材料上的吸附、降解机理以及光催化降解动力学和关键影响因子，建立纳米材料可见光下降解水体污染物的处理体系，为水体有机污染物的有效降解和消除提供一条环境友好的新方法，对保护生态环境和人民群众身体健康具有重要的现实意义。

光催化高级氧化技术在污水处理应用中，研制新型可见光光催化材料是目前研究热点，本项目主要研究内容是制备新型Bi系光催化材料锆酸铋（Bi2Zr2O7），并将Ag/AgX/(X = Cl, I)沉积在Bi2Zr2O7表面构筑等离子体复合光催化剂Ag/AgX/Bi2Zr2O7 (X = Cl, I)，Ag纳米粒子的等离子体效应能够提高太阳光利用率，复合材料异质结构可以抑制光生载流子复合，提高量子效率，从而提高光催化能力。.研究发现，通过简易的沉淀-煅烧法制备Bi2Zr2O7，帯隙宽度约为2.59eV，最大光响应波长达480nm，在模拟太阳光照射下4h对甲基橙的降解率达到近50%。在溶解过程中添加葡萄糖，采用沉淀-煅烧法制备Bi2Zr2O7纳米片，通过超声波协助沉淀-光还原技术在Bi2Zr2O7纳米片表面沉积Ag/AgX(X=Cl, I)纳米颗粒。通过SEM、TEM、XRD、DRS、XPS观察材料的形态结构、晶相结构、光学吸收性能、元素表面化学形态。Bi2Zr2O7 材料为片状结构，厚度10-20nm。Ag/AgI/Bi2Zr2O7复合材料中Ag/AgI粒径约15nm，XRD结果显示AgI为立方相，XPS和HRTEM结果显示金属Ag纳米粒子存在，Ag/AgI/Bi2Zr2O7复合材料具有良好的可见光吸收性能和可见光催化剂降解甲基橙性能，可见光光照2 h可以去除78%甲基橙。Ag/AgI/Bi2Zr2O7复合材料具有良好的稳定性和重复利用性，循环使用4次，其光催化降解能力没有明显降低。Ag/AgCl/Bi2Zr2O7复合材料中Ag/AgCl粒径约10nm，XRD结果显示AgCl和Ag均为立方相，XRD、XPS和HRTEM证明光还原过程中金属Ag纳米粒子生成，DRS显示Ag/AgCl/Bi2Zr2O7复合材料具有良好的可见光吸收性能。Ag/AgCl/Bi2Zr2O7复合材料在可见光照射下，具有极优异的光催化降解能力，在60 min内降解去除溶液中全部甲基橙污染物。.本项目的相关研究成果，已发表SCI收录论文4篇，其中2区2篇，3区2篇，申请专利1项，该研究为新型可见光催化复合材料的研制及其在污水处理应用中提供科学参考。