可见光催化剂钨酸铋的合成及光催化性能研究

发布时间：2018-06-08 19:25

  本文选题：钨酸铋 + 半导体　； 参考：《天津科技大学》2017年硕士论文

【摘要】：近年来,由于在治理环境污染和光解水制氢方面表现出潜在的应用前景,光催化技术得到了研究者的广泛关注。紫外光响应光催化剂如Ti02禁带宽度约为3.2ev,仅吸收占太阳光4%的紫外光(λ400nm)部分,严重限制了太阳能的利用,而太阳光中的可见光部分占太阳光能量的45%,因此,可见光响应光催化剂成为当前研究的热点和重点。其中,钨酸铋(Bi2W06)的禁带宽度约为2.7ev,是潜在的可见光响应光催化剂。本文采用溶胶凝胶法制备可见光催化剂Bi2W06,并利用X射线衍射、扫描电镜、红外光谱和紫外可见分光光度计等技术手段表征样品的结构和性能。以紫外光为光源,甲基橙为降解对象,考察了催化剂焙烧温度、甲基橙溶液pH、甲基橙浓度、催化剂用量对催化体系的影响。并以氙灯模拟太阳光,考察了两种光源在体系中的光催化活性。光催化降解实验表明,甲基橙溶液pH=3,催化剂用量为1.2g/L,甲基橙溶液浓度为5mg/L时,使用400℃焙烧的Bi2W06,有最好的光催化活性。1.2g/L、400℃焙烧的Bi2W06粉末,降解10mg/L、pH=3的甲基橙溶液,氙灯光照150min降解率达到92%,太阳光降解率达到了 58%。采用无模板水热法,通过HNO3和NH3·H20调节体系的pH值,合成不同形貌和光催化活性的Bi2W06粉体催化剂。并利用X射线衍射、透射电镜、红外光谱、紫外可见分光光度计、紫外可见漫反射光谱和N2吸附脱附法等技术手段表征样品的结构和性能。光催化降解实验表明,在pH=7时,反应温度为180℃,反应时间为24h,合成了纳米尺寸的Bi2W06样品,且具有最佳的光催化活性,降解10mg/L的罗丹明B溶液,350w氙灯光照60min降解率达到了 95.6%。
[Abstract]:In recent years, photocatalytic technology has attracted wide attention due to its potential application in environmental pollution control and hydrogen production by photolysis water. The ultraviolet photocatalyst, such as Ti02 photocatalyst, has a band gap of 3.2evand absorbs only 4% of the solar light (位 400nm), which seriously limits the utilization of solar energy, while the visible light in the solar light accounts for 45% of the solar energy. Visible light-responsive photocatalyst has become the focus and focus of current research. The band gap of bismuth tungstate Bi2W06) is about 2.7 ev. it is a potential visible light responsive photocatalyst. In this paper, the visible light catalyst Bi2W06was prepared by sol-gel method. The structure and properties of the samples were characterized by X-ray diffraction, scanning electron microscopy, infrared spectroscopy and UV-Vis spectrophotometer. The effects of calcination temperature, pH of methyl orange solution, concentration of methyl orange and the amount of catalyst on the catalytic system were investigated with ultraviolet light as light source and methyl orange as degradation object. The photocatalytic activity of the two light sources in the system was investigated by using xenon lamp to simulate solar light. The photocatalytic degradation experiment showed that the best photocatalytic activity of Bi2W06 calcined at 400 鈩，

本文编号：1996921