碘化银复合材料的合成及其光催化性质研究

发布时间：2018-05-07 01:32

本文选题：Ag + I　；参考：《河南师范大学》2015年硕士论文

【摘要】：随着人类社会的发展和工业化水平的提高,环境污染和能源危机问题成为当今社会亟待解决的难题。半导体材料因其在太阳能转换和光氧化有机污染物方面的应用,近年来受到了很大的关注。迄今为止的科学研究中,发现Ti O2因对染料有好的降解性能,没有毒性,有较好的稳定性和价格低廉等集一身的优点,被认为是最优秀的材料之一。然而Ti O2是宽带隙材料,只吸收自然光中3-4%的紫外光,所以很大程度上限制了其在实际工业中的应用。因此,研究出一种高可见光利用率的半导体材料,在光催化领域已经成为一个炙手可热的话题。卤化银及其复合光催化剂因提供了一个拓宽可见光吸收波长和有效的分离载流子的方法受到广泛关注。所以,利用碘化银的可见光响应性能,与多种短波吸收的半导体进行复合,使吸收波长红移。合成出新颖结构和性能的碘化银复合材料具有很重要的科学意义。本文主要研究工作如下:(1)选用P,I2和Ag2O为合成原料,通过简单低温水热方法,一步制备出了高收率的Ag/Ag I催化剂。并通过XRD,XPS,SEM,TEM,UV-vis等测试方法对样品进行了表征。通过上述一系列表征方法显示,当反应条件为:温度120oC,时间4 h时,合成的样品的形貌最均一。实验选取罗丹明B(Rh B)为目标降解物,检测样品在可见光下,对模拟废水的分解效率为97.8%。本章最后对Ag/Ag I样品降解模拟污水Rh B,可能的催化机理进行了详细探究。(2)采用简单水热方法合成花状Zn O,并通过原位沉积的方法对其进行不同含量纳米Ag I的修饰,从而得到不同负载量的Ag I/Zn O异质结。并探讨了在模拟太阳光下改变条件,对罗丹明B溶液催化效率的影响。系统研究了Ag I负载量、催化剂添加量、染料初始浓度等因素对光催化活性的影响。实验结果表明当Ag I负载量为10%,催化剂添加量为0.3 g/L,染料初始浓度为10-5 mol/L,Rh B的降解率最佳达98.5%。本文中对各种反应因素如何影响Ag I/Zn O光催化降解Rh B水溶液活性进行了合理分析。并对其可能的光催化机理和样品循环稳定性,以及在自然光下的光降解情况进行了详细的研究。(3)采用溶剂热方法合成3D蒲公英微球状Ti O2,并通过原位沉积的方法对其进行不同摩尔含量纳米Ag I的修饰,从而得到不同负载量的Ag I/Ti O2复合物。以不同染料为目标降解物,检测所制备样品在可见光下的光催化活性。并系统的研究了Ag I负载量、染料,光源等因素对光催化活性的影响。实验结果表明当Ag I负载量为15%,催化剂添加量为1.6 g/L,染料初始浓度为80 mg/L,活性艳红X-3B的降解率达到98.6%。本文中对各种反应因素如何影响Ag I/Ti O2光催化降解X-3B水溶液活性进行了合理分析。并对其可能的光催化机理和样品循环稳定性,以及在自然光下的光降解情况进行了详细的研究。
[Abstract]:With the development of human society and the improvement of industrialization level, environmental pollution and energy crisis have become a difficult problem to be solved. Semiconductor materials have attracted much attention in recent years because of their applications in solar energy conversion and photooxidation of organic pollutants. So far, it has been found that TIO _ 2 is considered as one of the most excellent materials because of its good degradation of dyes, no toxicity, good stability and low cost. However, TIO _ 2 is a wide band gap material, which only absorbs 3 ~ 4% of ultraviolet light in natural light, so its application in practical industry is limited to a great extent. Therefore, a semiconductor material with high visible light efficiency has become a hot topic in the field of photocatalysis. Silver halide and its complex photocatalysts have attracted wide attention for their ability to broaden the visible light absorption wavelength and to effectively separate carriers. Therefore, the visible light response of silver iodide is combined with a variety of shortwave absorption semiconductors to make the absorption wavelength red shift. It is of great scientific significance to synthesize silver iodide composites with novel structure and properties. The main work of this paper is as follows: (1) the high yield Ag/Ag I catalyst was prepared by a simple low temperature hydrothermal method. The samples were characterized by means of XRDX, XRDX, SEMX, TM, TEM, UV-vis and so on. The results show that the morphology of the synthesized samples is the most uniform when the reaction conditions are 120oC and 4 h. Rhodamine B(Rh B was selected as the target degradation material. The degradation efficiency of the sample was 97.88 under visible light. In the end of this chapter, the possible catalytic mechanism of degradation of simulated wastewater Rh B by Ag/Ag I sample was studied in detail. (2) Flower Zn O was synthesized by simple hydrothermal method and modified by in situ deposition with different content of nano Ag I. The Ag I/Zn O heterostructures with different loads are obtained. The effect of changing conditions on the catalytic efficiency of Rhodamine B solution under simulated solar light was discussed. The effects of Ag I loading, catalyst addition and initial dye concentration on photocatalytic activity were systematically studied. The experimental results show that the optimum degradation rate of Rh B is 98.5 when the loading amount of Ag I is 10 g / L, the amount of catalyst is 0.3 g / L, and the initial concentration of dye is 10 ~ (-5) mol / L ~ (-1) Rh _ B. In this paper, the influence of various reaction factors on the photocatalytic degradation of RHB aqueous solution by Ag I/Zn O was reasonably analyzed. The possible photocatalytic mechanism and the stability of the sample cycle were also studied. The photodegradation of 3D dandelion microsphere TIO _ 2 was synthesized by solvothermal method and modified by in-situ deposition with different molar content of nano-Ag _ I. The Ag I/Ti O 2 complex with different loading amounts was obtained. The photocatalytic activity of the prepared samples under visible light was determined by using different dyes as the target degradation materials. The effects of Ag I loading, dye and light source on photocatalytic activity were studied systematically. The experimental results show that the degradation rate of reactive brilliant red X-3B reaches 98.6 when the loading amount of Ag I is 15, the amount of catalyst added is 1.6 g / L, the initial concentration of dye is 80 mg / L, and the degradation rate of reactive brilliant red X-3B is 98.6%. In this paper, the influence of various reaction factors on the photocatalytic degradation of X-3B aqueous solution by Ag I/Ti O _ 2 was reasonably analyzed. The possible photocatalytic mechanism, the stability of the sample cycle and the photodegradation under natural light were studied in detail.
【学位授予单位】：河南师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33

【相似文献】