软铋矿类微纳米材料的液相制备及光催化性能研究

发布时间：2018-02-15 23:59

本文关键词： 软铋矿可控合成溶液法异质结光催化　出处：《安徽理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：环境污染问题日益严峻,研制开发具有高活性的软铋矿类可见光催化剂具有重要意义。但目前文献报道的软铋矿材料,其自身结构及功能缺陷从而导致比表面积较小,光生电荷的分离效率较低,可见光催化活性不高。本文主要讨论了半导体光催化剂的光催化机理,影响光催化性能的因素,并详细介绍了提高光催化剂催化性能的途径以及光催化剂的表征手段,拟采用温和的水热合成法,通过水溶性和高粘度的表面活性剂控制反应速率,从而诱导纳米单元自组装,制备出具有高比表面积的Bi12MO20-x(M = Si、Ti、Zn)多级结构;进一步在材料表面进行半导体复合,构筑相应的多级复合光催化剂,促进光生电荷的高效分离;以罗丹明B可见光催化降解为探针反应,并结合XRD、光谱分析等方法,探讨产物的微结构对载流子的分离、转移以及催化活性的影响;揭示此类光催化剂高活性的本质因素。该项目的实施将丰富软铋矿材料的制备技术,并为拓展新型光催化材料提供新的研究思路。本文得出以下结论:1.实验通过水热法合成了多级立方块状的Bi12SiO20,并对其形貌与结构进行了 X射线粉末衍射(XRD)、扫描电子显微镜(SEM)、能谱(EDS)、高分辨透射电镜(HRTEM)和X射线光电子能谱(XPS)等表征,同时对其在可见光下降解罗丹明B的光催化过程以及光催化机理进行了详细的研究。2.实验通过水热合成法,基于异质结的设计理论,成功制备了一种新颖的Bi12ZnO20-Bi2WO6异质结光催化剂,以预先制备的Bi2WO6为Bi源,通过可控部分沉淀转移法成功制备了一种新颖的Bi12ZnO20-Bi2WO6(BZO-BWO)异质结光催化剂。为了研究其光催化性能,以所制备的BZO-BWO为光催化剂,以罗丹明B(RhB)为模拟染料,研究其对染料的降解效率,并对催化机理进行了研究。3.实验采用水热法,使部分沉淀成功转化,制备出了一种新颖的Bi12TiO20-Bi2WO6(BTO-BWO)异质结光催化剂。光催化实验表明,在紫外-可见光的辐射下Bi12TiO20-Bi2WO6异质结对降解RhB具有超高的光催化活性。最后,本文对其光催化机理进行了讨论,分析了光生电荷分离过程。
[Abstract]:The problem of environmental pollution is becoming more and more serious, so it is of great significance to develop visible light catalyst with high activity of soft bismuth ore. However, the structure and function defects of soft bismuth mineral materials reported in the literature at present lead to smaller specific surface area. The separation efficiency of photogenerated charge is low and the visible photocatalytic activity is not high. This paper mainly discusses the photocatalytic mechanism of semiconductor photocatalyst and the factors affecting its photocatalytic performance. The ways to improve the photocatalytic performance and the characterization methods of photocatalyst were introduced in detail. The method of mild hydrothermal synthesis was used to control the reaction rate through water-soluble and high-viscosity surfactants, thus inducing the self-assembly of nano-units. The multistage structure of Bi12MO20-x(M with high specific surface area was prepared, and the semiconductor composite was carried out on the surface of the material, and the corresponding multistage composite photocatalyst was constructed to promote the efficient separation of photogenerated charges. The catalytic degradation of rhodamine B in visible light was used as a probe reaction. The effects of the microstructure of the product on the separation, transfer and catalytic activity of carriers were investigated by means of XRD and spectroscopic analysis. The implementation of this project will enrich the preparation technology of soft bismuth ore materials. In this paper, the following conclusions are drawn: 1. The multilevel cubic bulk Bi12SiO20 has been synthesized by hydrothermal method. The morphology and structure of Bi12SiO20 have been characterized by X-ray powder diffraction (XRD) and scanning electricity (SEM). The electron microscopes were characterized by SEM, EDS, HRTEM (high resolution transmission electron microscopy) and X-ray photoelectron spectroscopy (XPSs). At the same time, the photocatalytic process and photocatalytic mechanism of Rhodamine B were studied in detail. 2. A novel Bi12ZnO20-Bi2WO6 heterojunction photocatalyst was successfully prepared by hydrothermal synthesis based on the design theory of heterojunction. A novel heterojunction photocatalyst, Bi12ZnO20-Bi2WO6WO BZO-BWO-BWO, was successfully prepared by controlled partial precipitation transfer method using pre-prepared Bi2WO6 as Bi source. In order to study its photocatalytic properties, the prepared BZO-BWO was used as photocatalyst and Rhodamine Bhl RhBas as mimic dye. The degradation efficiency of the dye was studied and the catalytic mechanism was studied. 3. A novel heterojunction photocatalyst Bi12TiO20-Bi2WO6WO (BTO-BWOO) was prepared by hydrothermal method. The photocatalytic activity of Bi12TiO20-Bi2WO6 heterogeneity pair degradation of RhB under UV-Vis radiation is very high. Finally, the photocatalytic mechanism is discussed and the process of photogenerated charge separation is analyzed.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36

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