光化学制备具有光催化功能的SnO2微/纳结构及其复合材料

Tin oxide (SnO2) is an important n-type semiconductor and has been considerably used in photocatalysis. Up to now, a variety of techniques have been devoleped to prepare SnO2 photocatalyst including sol-gel,hydrothermal method, chemical vapor deposition method. Generally, these preparation methods involve more than one step and some of these methods involve expensive starting material with high-temperature or high pressure synthetic process. Therefore, development of high-output, low-cost and simple synthesis approaches of SnO2 with high photocatalytic activity is necessary. Photochemical preparation technology is a promising way to prepare semiconductor materials because of lower energy consumption and less environmental pollution. In this project, based on the photocatalytic application, micro/nano structure SnO2 and its composites will be prepared directly using a room temperature photochemical synthesis method. The resulting various micro/nano structures maybe exisit some element lost, element rich or defects because of photochemical reaction at the interface, which would influence the photo-electron transfer properties of SnO2 in photocatalysis. In this work, we will investigate preparation and construction of micro/nano structure SnO2 under the low power ultra-violet light or sunlight irradiation at room temperature, and discuss the related photochemical reactions mechanism. The resulting materials will be characterized by various analytical techniques and their photocatalytic activity also be evaluated. The effect of different variables on micro-structure, composition and photocatalytic properties will be investigated in detail. Further, in order to increase the photocatalytic performance, conjugated polymer doped or loading SnO2 composites will also be prepared with photochemical method. The effect of structure, composition, and interface of the composites on the photocatalytic activity will be investigated, and the relative photocatalytic mechanism will also be discussed. The objective of this project is to establish a new room method to prepare micro/nano structure SnO2 and its composites with high photocalytic activity, and further to develop a kind of new technology to prepare,load,and dope photocatalyst. At present, the application of this project will be beneficial to promote SnO2 application in photocatalysis field.

SnO2是一种重要的半导体材料，发展其室温制备技术并拓宽其在光催化领域的应用范围具有重要的理论和现实意义。本项目拟以SnO2的光催化功能为牵引，引入简便、廉价、低温、绿色的光化学合成技术，制备SnO2微/纳结构及其复合材料。所合成微/纳米结构材料通常会因光化学反应而造成一定的元素缺失、富集或空位形成，这些特点对材料的光-电子转移具有重要影响，在光催化领域，具有重要的应用。本项目将主要研究利用低功率紫外光或太阳光控制合成SnO2微/纳结构，研究合成中的光化学反应机理；分析合成条件、形态控制因素、材料组成、光催化性能之间的量化关系。在此基础上，利用共轭聚合物对其进行掺杂复合，制备SnO2复合光催化材料，探讨光化学条件下的复合与负载原理，优化其光催化性能。本项目实施将建立新的SnO2微/纳结构材料室温合成方法，促进SnO2在光催化领域的实际应用，获得一类催化剂制备、负载和复合新技术。

本项目从现有光催化剂制备能耗较高，且SnO2光催化性能开发不足的现状出发，利用简单、廉价、低温、绿色的光化学合成技术，设计合成了系列微/纳结构化SnO2。研究了反应条件对产物产率，形貌和结构的影响，分析了其中所涉及的光化学反应机理，评价了所制备材料的光催化性能。取得的主要研究成果包括：（1）利用二价锡盐为原料，通过加入表面活性剂，控制制备了棒状、片状、球状和无定型颗粒状的Sn02微/纳结构。获得了在室温下光化学制备具有光催化功能的二氧化锡微/纳结构的方法. 该方法具有能耗低、环境友好、产物产率高、反应条件温和操作简单等优点。（2）完成了利用聚合物微球为模版，通过光化学法构筑SnO2复合微球和空心微球工作。获得了简单，快速的制备SnO2微球的方法。所制备的SnO2空心微球具有较强的光催化活性。（3）通过紫外光辐照诱导噻吩单体在SnO2表面原位聚合制备了PTH/SnO2共轭聚合物复合材料。PTH/SnO2能提高SnO2在太阳光下的光催化性能。（4）通过光辐照诱导Ag+在SnO2表面沉积，制备了Ag/SnO2复合光催化材料。SnO2表面修饰适当的银有利于进一步提高SnO2的光催化性能。（5）对产物的光催化性能进行了系统表征，发现所制备的系列SnO2微/纳结构有优良的光催化活性，可光催化降解有机染料。光化学制备的SnO2与共轭聚合物或贵金属复合掺杂后，当光照激发后，可提高光生电子的载流子的分离效率，有效抑制光生电子-空穴的复合，从而提高光催化降解效率。所制备的SnO2材料有望作为光催化剂应用在环境污染处理领域。