原位离子交换法合成AgBrAg3PO4复合光催化材料
毕业论文关键词 可见光催化 Ag3PO4 复合光催化剂 离子交换法 = Title In situ synthesis of ion exchange AgBr/Ag3PO4 photocatalytic material
Abstract Ag3PO4 can absorb visible light less than 530 nm with quantum yield up to 90% and shows strong oxidability and has great potential applications in degrading organic pollutants and photocatalytically splitting water. However, Ag3PO4 is a photosensitive, and water-soluble, which greatly reduces its structural stability in the photocatalytic process If without sacrificing agent in the photocatalysis,the photoreduction of Ag3PO4 to metal Ag will occur, resulting in the reduced photocatalytic activity. Therefore, how to develop a convenient and effective way to improve the stability of photocatalyst Ag3PO4, and increase its photocatalytic activity without sacrificing agent adding, will be the focus of future research. In this research, a mild liquid phase synthesis route was used prepare Ag3PO4 photocatalytic material with high catalytic activity, Furtherly, Ag3PO4/AgBr composite photocatalyst was synthesized throught an in-situ ion exchange method. All samples were characterized by XRD, SEM, EDS, Raman and UV–vis DRS, and the photocatalytic activities of the samples were assessed by monitoring the decolorization process of Rhodamine B (RhB) dye under visible light without any sacrificial reagents. the relationship between the performance and synthetic route, structure, and morphology was investigated, which can provide guidance for the preparation of composite catalyst, mechanism analysis, and potential applications.
Keywords Visible light catalytic Ag3PO4 Composite photocatalyst Ion exchange
目次
1绪论1
1.1半导体光催化材料简介.1
1.2光催化材料反应机理..2
1.3半导体光催化活性的影响因素.3
2Ag3PO4光催化剂..4
2.1Ag3PO4材料概述..4
2.2Ag3PO4材料光催化机理探索4
2.3Ag3PO4材料合成方法5
2.4Ag3PO4材料分析方法5
3实验部分.7
3.1实验试剂和仪器.7
3.2制备方法.7
3.3样品检测与表征.9
3.4光催化性能检测.9
3.5循环稳定性检测..10
4结果分析..11
4.1XRD结果分析11
4.2SEM-EDS表征分析..11
4.3UV-visDRS分析.13
4.4Ag3PO4可见光催化活性分析.16
结论.21
致谢22
参考文献..23
1 绪论 1.1 半导体光催化材料简介 二十一世纪，世界各地都面临如何又快又好的发展的首要问题。生态破坏和资源稀缺是最主要的两个困难。近年来，中国虽然各方面都发展很快，但环境也受到了相当严重的污染。半导体光催化法拥有很大的开发潜力可以应对这些困扰。首先，光催化剂材料可以很有效的利用取之不尽的太阳能。再者，光催化材料还可以非常高效的治理各式各样的污染物。因而，应对环境问题时，光催化技术是极具有影响力的。随着科研人士的不断探索，光催化材料的各种优点及其应用都被不断发掘出来。其中光催化材料因为价格很便宜，没有毒性，性能很稳定等，已经在污染物的清除和防治等得到了很大的使用[1]。 自1972年时，东京大学 Fujishima A 同Honda K 教授[2]在自然杂志上阐述了紫外光的辐射下 TiO2材料能够把 H2O 降解。研究人员一致认可 TiO2材料有着非常高效的，而且很有潜能的一种催化剂。因为TiO2材料性能极其的稳定，使用时很安全，不带有任何的毒性，而且其市场价格也非常便宜。可是，即便这几十年来实验人员们在不断地发掘，半导体光催化技术依旧无法做到很好的使用太阳光能。最重要的原因是 TiO2材料的Eg很大，大概是 3.2 eV。对应的激发波长是在300nm 以下的紫外光部分。众所皆知，紫外光拥有的能量仅占据太阳光能的几个百分点而已。因而，TiO2 材料对太阳能很小的使用率极大地影响了它在各方面的使用[5]。是以，开发出新的催化材料已然是现代科研的重要项目之一。