几种锌基光催化剂的制备及其光催化性能的研究

发布时间：2018-01-22 06:24

  本文关键词： Zn基 纳米复合物 固相法 水热法 溶剂热法 光催化性能　出处：《淮北师范大学》2016年硕士论文　论文类型：学位论文

【摘要】：光催化技术是一种新型的废水处理和空气净化技术,其具备绿色环保、稳定、高效等优点,在环境污染治理方面有良好的应用前景。锌基半导体是一种重要的光催化材料,然而有关锌基光催化剂的制备方法及其在实际应用方面还存在许多问题,例如制备过程繁琐复杂,实际应用中存在光催化效率低,光催化剂分离回收困难,其循环利用效率和光催化效率低等问题,有待于进一步改进和优化。本论文是在前人研究的基础上,对现有的部分锌基光催化剂的制备方面进行了优化和改进,同时,通过负载等方法对其改性,方便了光催化剂的分离回收及其循环利用。主要研究内容和结果如下:1、以Na2WO4·2H2O和Zn(NO3)2·6H2O为原料,利用机械球磨固相法,制备纳米Zn WO4光催化剂。通过X-射线衍射仪(XRD)、透射电子显微镜(TEM)对所制得样品的物相和形貌进行表征,研究制备条件对产物组成和结构的影响,并对其光催化性能进行了初步探讨。结果表明,在室温条件下,不需要添加任何辅助试剂,采用机械球磨固相法成功地制备出Zn WO4纳米片。同时,光催化实验也表明,Zn WO4纳米片在紫外光照射下具有较好的光催化性能,3小时后甲基橙的降解率达到91%。2、以Na2WO4·2H2O,Bi(NO3)3·5H2O和Zn(NO3)2·6H2O为原料,采用机械球磨固相法制备出Zn WO4/Bi2WO6复合物。利用XRD、TEM、TEM-mapping对产物的物相组成、形貌进行了表征。探讨了球磨反应条件对产物的影响,并选取甲基橙作为目标降解物研究所得产物在可见光下的的光催化性能。结果表明,Zn WO4/Bi2WO6复合物光催化活性明显优于单一的Zn WO4或Bi2WO6。在球磨反应2小时并在350℃煅烧4h所得Zn WO4/Bi2WO6复合物表现出最高的光催化活性,在可见光下光催化反应1.5小时后,甲基橙的降解率达到96%。3、以SnCl4.4H2O、ZnSO4.7H2O和硫脲为原料,采用水热一锅法制备了ZnS-SnS2复合光催化剂。利用XRD、TEM对产物的物相组成和形貌进行了表征,并探讨了水热条件对产物的影响。选取甲基橙作为目标降解物研究合成产品的光催化性能。结果表明,合成的Zn S-Sn S2复合物光催化降解效率明显优于单一的Zn S和SnS2,在160℃下反应8 h合成的ZnS-SnS2表现出最高的光催化活性,光照3小时后,甲基橙的降解率达到89%。4、以葡萄糖和Fe3O4为原料制备出Fe3O4@C复合物并以此为载体,采用溶剂热法,以乙二醇为溶剂,加入Cu Cl2·2H2O,Sn Cl4·4H2O,Zn SO4·7H2O,硫脲,制备出具有磁性的Fe3O4@C@Cu2Zn Sn S4纳米光催化剂复合物。利用XRD、TEM对产物的物相组成和形貌进行了表征,探究了不同溶剂用量、反应时间、反应温度对Fe3O4@C@Cu2Zn Sn S4结构和性能的影响。
[Abstract]:Photocatalytic technology is a new type of wastewater treatment and air purification technology, which has the advantages of green environmental protection, stability, high efficiency and so on. Zinc based semiconductor is an important photocatalytic material. However, there are still many problems in the preparation of zinc-based photocatalyst and its practical application. For example, the preparation process is complicated, the photocatalytic efficiency is low, the separation and recovery of photocatalyst is difficult, the recycling efficiency and photocatalytic efficiency are low. On the basis of previous studies, the preparation of some zinc-based photocatalysts has been optimized and improved. At the same time, it has been modified by loading and other methods. The separation and recovery of photocatalyst and its recycling were facilitated. The main research contents and results were as follows: 1. Na2WO4 路2H2O and Zn(NO3)2 路6H2O were used as raw materials. Nanocrystalline Zn WO4 photocatalysts were prepared by mechanical ball milling solid state method. The phase and morphology of the samples were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The effect of preparation conditions on the composition and structure of the product was studied and the photocatalytic properties of the product were preliminarily discussed. The results showed that no auxiliary reagent was needed at room temperature. Zn WO4 nanocrystals were successfully prepared by mechanical ball milling solid state method. Meanwhile, the photocatalytic experiments showed that Zn WO4 nanoparticles had better photocatalytic properties under UV irradiation. After 3 hours, the degradation rate of methyl orange reached 91%. The raw materials were Na2WO4 路2H _ 2O, Bigno _ 3H _ 3O _ 3 路5H _ 2O and Zn(NO3)2 路6H _ 2O. Zn WO4/Bi2WO6 complex was prepared by mechanical ball milling solid phase method. The morphology was characterized and the effect of milling reaction conditions on the product was discussed. Methyl orange was selected as the target degradation material to study the photocatalytic properties of the product under visible light. The photocatalytic activity of Zn WO4/Bi2WO6 complex was obviously superior to that of Zn WO4 or Bi 2WO6.The Zn was prepared by ball-milling reaction for 2 hours and calcined at 350 鈩，

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