暴露{101}面自掺杂TiO2纳米片薄膜光电极制备及其可见光降解水中PPCPs研究

In order to improve the visible light photocatalytic (PC) performance and separation efficiency of photogenerated charge carriers of materials, self-doped TiO2 nanosheets films (STNSFs) photoelectrodes with exposed{101} facets were rapidly fabricated by integration hydrothermal method and solution reduction strategy. Subsequently, the intrinsic relationships among micro morphology and structure, surface chemical states, separation efficiency of photogenerated charge carriers, and PC performance of the STNSFs photoelectrodes with exposed {101} facets were investigated through transmission electron microscope, X-ray photoelectron spectroscopy, electron spin resonance and time-resolved surface photovoltage spectrum techniques. Meanwhile, both the formation principle and enhanced visible light PC mechanism were clarified. Based on the adsorption and decomposition behaviors of pharmaceutical and personal care products(PPCPs) in the reaction system on the surface of the STNSFs photoelectrodes with exposed {101} facets, the effects of different parameters and reactive species on the visible light PC efficiencies were explored. Furthermore, the corresponding models and kinetic equations of PC degradations were concluded, as well as the PC mechanism for the degradation of PPCPs in water, which could provide a feasible strategy for the design and development of environment-friendly functional materials for emerging contaminants containing wastewater purification. In addition, the high PC efficiency for the removal of PPCPs in water could also provide technical support for the industrialized application. The synthetic strategy in this project possesses the characteristics of simple-operation, fast-reaction and easy enlarged synthesis.

为提高材料的载流子分离效率与可见光催化活性，本课题拟利用水热法与液相还原法快速构建暴露{101}面自掺杂TiO2纳米片薄膜光电极。通过透射电子显微镜、X-射线光电子能谱、电子自旋共振以及时间分辨表面光电压谱等测试揭示暴露{101}面自掺杂TiO2纳米片薄膜光电极微观形貌结构-表面化学形态-载流子分离效率-光催化活性之间的内在关联，并阐明其形成机制与可见光催化活性提高机理。通过研究反应体系中药品及个人护理品在暴露{101}面自掺杂TiO2纳米片薄膜光电极表面的吸附和降解行为，探究不同影响因素与活性物种对其可见光催化效率的作用规律，归纳出相应的光催化降解模型与动力学方程，解析其对水中药品及个人护理品的光催化降解机理，为高效去除水中新兴污染物的水净化环境功能材料的设计与开发提供切实可行的策略，为光催化技术的工业化提供技术支持。本项目拟采用的合成策略具有操作简单、反应迅速且容易放大合成等特点。

新兴污染物在市政水厂中被频繁检出，对人类环境带来极大的危害。而粉末态催化剂存在不易回收，难重复使用的缺陷。因此，本项目在Ti箔基底上原位生成了TiO2纳米棒/纳米片（TiO2 NRs/NSs）光电极，对其进行自掺杂与AgBr修饰以及MS (M=Bi, Sn)纳米粒子改性研究，并对其物理化学与光电化学性能以及光催化活性进行了系统分析。开展了以下研究工作：.为研究微观结构对TiO2光催化剂光催化性能的影响，通过制备工艺参数优化，制备了TiO2 NRs/NSs光电极。优化后的TiO2 NRs/NSs光电极具有良好的紫外-可见光吸收能力与光电化学性能以及可见光催化活性。在35 W氙灯光照150 min后，对亚甲基蓝（MB）的光催化去除效率为73.56%。.为克服可见光利用率低和载流子复合率高的缺陷，构筑了Ti3+自掺杂（Ti3+/TiO2 NRs/NSs）与AgBr纳米饼修饰的TiO2 NRs/NSs（AgBr-Ti3+/TiO2 NRs/NSs）光电极，并进行了物理化学及光电催化性能测试。结果表明：Ti3+/TiO2 NRs/NSs和AgBr-Ti3+/TiO2 NRs/NSs光电极对MB的光催化降解效率能够分别达到89.61%和98.7%，此外，其光电流密度、载流子浓度以及光电化学性能均得到明显的改善。.为进一步提高TiO2 NRs/NSs光电极的光催化性能，制备了MS (M=Bi, Sn)改性的TiO2 NRs/NSs光电极（MS/TiO2 NRs/NSs）。结果表明：经Bi2S3和SnS纳米粒子表面改性之后，TiO2 NRs/NSs光电极的光转化效率、载流子寿命、电荷层厚度、载流子分离效率以及光催化活性均显著增加。150 min光照后，SnS/TiO2 NRs/NSs光电极对MB的降解效率为96.3%。.以水中新兴污染物布洛芬（IBU）为目标物，运用制备的改性TiO2 NRs/NSs光电极在可见光照下对其进行光催化降解，并研究了IBU降解的影响因素及动力学特征。结果表明：SnS/TiO2 NRs/NSs光电极对IBU表现出最好的光催化降解效能。光照180 min后，其对IBU的光催化TOC去除率为72%，且循环使用4次后依然具有良好的光催化活性。.本项目的开展与实施为高效净化水中新兴污染物的环境功能材料开发提供新的思路、理论基础和技术支持，具有重要的科学意义。