改性纳米氧化锌材料的冻干法制备及光催化性能研究

发布时间：2018-05-08 02:22

本文选题：光催化 + 纳米氧化锌　；参考：《北京化工大学》2017年硕士论文

【摘要】：治理工业染料废水污染物的必要性越来越受到重视,对难降解染料的深度降解是研究的难题与热点。近年来,多相光催化技术应用于降解染料废水,因其强氧化性与广谱性,受到普遍关注。本论文采用聚合物辅助冻干法制备纳米氧化锌光催化剂,并对氧化锌进行离子掺杂改性,以偶氮类的甲基橙和蒽醌类的活性艳蓝KN-R为模拟染料污染物,对光催化剂的性能进行实验研究与降解机理探讨。首先论文考察了染料初始浓度、光催化剂的质量浓度、pH和光源因素对于光催化剂纳米氧化锌光催化降解甲基橙过程的影响,确定了单因素实验降解的最佳条件分别为甲基橙的初始浓度为10 mg·L~(-1),加入纳米氧化锌的质量浓度为400 mg·L~(-1),弱酸或强碱性条件,并给予365 nm主波长的紫外光照。然后以Box-Behnken试验设计方法建立了甲基橙的降解率与染料浓度、纳米氧化锌质量浓度、pH的二次多项式响应曲面预测模型,该模型能预测95%的响应值,且方差结果显示染料初始浓度和纳米光催化剂质量浓度的交互作用对降解效果最为显著。随后,分别对纳米氧化锌掺杂铝、铁、钴、铈、镧离子五种金属离子,其中,制备得到的铝掺杂纳米氧化锌表现出较氧化锌优异的活性,对10 mg·L~(-1)的甲基橙以及60 mg·L~(-1)的活性艳蓝,均能在1小时内达97%的降解率,远远高于纳米氧化锌2小时约6Fig.5%的降解率。并且XRD分析表明,铝离子掺杂使得粒径变小;8%掺杂质量分数的样品SEM照片显示其改变了纳米氧化锌的表面形貌。最后,以Langmuir-Hinshelwood为动力学模型,对比了纳米氧化锌和铝掺杂纳米氧化锌两种光催化剂对甲基橙光催化反应的动力学方程。采用液相色谱对甲基橙及活性艳蓝KN-R的不同降解时间的样品进行分析。
[Abstract]:The necessity of controlling pollutants in industrial dye wastewater has been paid more and more attention, and the deep degradation of dyestuffs is a difficult problem and hot spot. In recent years, multiphase photocatalytic technology has been applied to the degradation of dye wastewater. Because of its strong oxidizability and broad-spectrum, it has been widely concerned. This paper uses polymer assisted freeze drying to prepare nano Zinc Oxide. Photocatalyst, and the modification of Zinc Oxide by ion doping, with azo methyl orange and anthraquinone active brilliant blue KN-R as the simulated dye contaminants, the performance of the photocatalyst was studied and the degradation mechanism was discussed. First, the initial concentration of the dye, the mass concentration of the photocatalyst, the pH and the light source were investigated. The effect of nano Zinc Oxide on the photocatalytic degradation of methyl orange was determined. The optimum conditions for the single factor experimental degradation were 10 mg. L~ (-1) of methyl orange respectively. The mass concentration of nanoscale Zinc Oxide was 400 mg. L~ (-1), weak acid or strong alkaline condition, and the UV light was given to the main wavelength of 365 nm. Then, Box-Behnken test was used. The design method established the degradation rate and dye concentration of methyl orange, the mass concentration of nano Zinc Oxide, the two order polynomial response surface model of pH, which could predict the response value of 95%, and the result of variance showed that the interaction between the initial concentration of the dye and the mass concentration of nanometer photocatalyst was the most significant. Zinc Oxide is doped with five kinds of metal ions of aluminum, iron, cobalt, cerium and lanthanum ions. Among them, the prepared aluminum doped nanoscale Zinc Oxide shows excellent activity compared with Zinc Oxide, and the active brilliant blue of 10 mg. L~ (-1) methyl orange and 60 mg. L~ (-1) can reach 97% in 1 hours, far higher than that of nano Zinc Oxide in 2 hours about 6Fig.5% degradation. XRD analysis showed that the doping of aluminum made the particle size smaller, and the sample SEM with 8% doped mass fraction showed that it changed the surface morphology of the nano Zinc Oxide. Finally, the kinetic model of Langmuir-Hinshelwood was used to compare the photocatalytic reaction of two photocatalysts of nano Zinc Oxide and aluminum doped nanoscale Zinc Oxide to methyl orange. Mechanical equations. The samples with different degradation time of methyl orange and reactive brilliant blue KN-R were analyzed by liquid chromatography.

【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36;TQ132.41

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