稀土元素掺杂纳米ZnO功能材料的制备及性能研究

发布时间：2018-06-21 14:20

  本文选题：纳米氧化锌 + 掺杂　； 参考：《沈阳工业大学》2017年硕士论文

【摘要】：光催化氧化技术具有清洁性、高效性以及稳定性等众多特点,能够将光能转化为化学能,产生羟基自由基氧化水体中的难降解污染物质,受到了广泛的关注,为处理高难降解废水提供了一种新的方法。光催化技术中最重要的就是光催化材料的制备研究,半导体材料氧化锌是目前研究最热的光催化材料,具有很好的应用前景。本文研究纳米氧化锌的制备方法,通过稀土元素La掺杂和La-Cd共掺杂的研究,制备出高效稳定的光催化剂。考察复合催化剂的制备影响因素,以活性黑KNB染料溶液为模拟废水进行光催化降解,找出最佳的光催化降解条件并测试复合催化剂的稳定性。本文的主要研究成果如下:(1)微波法为纳米氧化锌的最佳制备工艺,并通过XRD和SEM表征对其微观结构进行分析,确定晶型为六方纤锌矿结构。紫外光照射下,利用不同条件制备的氧化锌对浓度为0.04g/L的活性黑KNB染料废水进行光催化降解,结果表明微波法制备氧化锌材料的最佳工艺条件为:n(六水合硝酸锌):n(尿素)=1:3,微波反应时间30min,微波加热功率640W,煅烧温度500℃。(2)La和Cd元素的掺杂未改变纳米氧化锌的主体结构,掺杂后的复合催化剂具有较高的光催化活性,La-Cd/ZnO复合光催化剂的最佳制备工艺为:镧镉掺杂比为2:1,微波反应时间30min,加热功率640W,煅烧温度500℃,反应溶液pH为7,最佳制备条件下,光催化降解活性黑KNB染料的降解率为98.9%。通过正交试验极差分析可知,制备因素对La-Cd/ZnO复合催化剂活性的影响排序为:煅烧温度镧镉掺杂比微波功率反应溶液pH。(3)考察光催化反应条件对La-Cd/ZnO复合催化剂降解染料废水的影响,实验结果证明光催化的最佳反应条件为:废水pH为7,染料初始浓度为0.08g/L,投加量为0.1g。紫外光照射2h对活性黑KNB的去除率为92.2%,通过多次重复使用,La-Cd/ZnO复合催化剂仍具有较高的光催化活性。
[Abstract]:Photocatalytic oxidation technology has many characteristics, such as cleanness, high efficiency and stability, which can convert light energy into chemical energy and produce hydroxyl radical oxidation of refractory pollutants in water. It provides a new method for the treatment of high-difficult-degradable wastewater. The preparation of photocatalytic materials is the most important in photocatalytic technology. The semiconductor material zinc oxide is the hottest photocatalytic material and has a good application prospect. In this paper, the preparation method of nanometer zinc oxide was studied, and high efficient and stable photocatalyst was prepared by La doping and La-Cd co-doping. The factors affecting the preparation of the composite catalyst were investigated. The reactive black KNB dye solution was used as the simulated wastewater for photocatalytic degradation. The optimum photocatalytic degradation conditions were found and the stability of the composite catalyst was tested. The main results of this paper are as follows: (1) Microwave method is the best preparation technology of nano-ZnO. The microstructure of nano-ZnO is analyzed by XRD and SEM, and the crystal structure is determined to be hexagonal wurtzite structure. Under ultraviolet irradiation, the reactive black KNB dye wastewater with 0.04g / L concentration of zinc oxide prepared under different conditions was photocatalytic degraded. The results show that the optimum technological conditions for the preparation of zinc oxide materials by microwave are: 1: n (zinc nitrate hexahydrate: 1: 3), microwave reaction time 30 min, microwave heating power 640 W, calcination temperature 500 鈩，

本文编号：2049002