取代Dawson结构HPC@TiO2分子印迹可见光催化剂的结构调控与降解PPCPs性能增强

Much attention has been devoted to development of novel technologies for degradation of pharmaceuticals and personal care products （PPCPs）due to their potential environmental threats. Titanium dioxide (TiO2) is widely used in photocatalytic degradation of PPCPs because of its high chemical stability, non-toxicity, and so on. However, TiO2 is effective only under ultraviolet radiation and the low quantum efficiency hindered its further utilization. Therefore, how to make use of TiO2 sunlight catalytic degradation of PPCPs is an environmental material problem, which need to be solved urgently. . This project prepares to take investigation on tunable microstructure and enhanced photocatalytic activity for PPCPs degradation of substituted Dawson type heteropoly compounds HPC@TiO2 molecularly imprinted visible light photocatalysts as the research object. Firstly, visible light responsive substituted Dawson type heteropoly compounds are synthesized via double decomposition reaction, embedded modification method and so on with rare earth or transition metal to replace the addenda atoms or counter cations. Secondly, molecular imprinted TiO2 photocatalysts are synthesized via sol-gel method and so on. Thirdly, substituted Dawson type heteropoly compounds HPC@TiO2 molecularly imprinted visible light photo-catalysts are constructed by impregnation method, etc. And then different techniques including XRD, etc. are employed to characterize substituted Dawson type heteropoly compounds HPC@TiO2 molecularly imprinted visible light photocatalysts. The indicator reaction, visible light photo-degradation of PPCPs acetosalicylic acid and 4-hydroxybenzoate, can be used to evaluate photocatalytic activities of the as-prepared samples ..To establish foundation for the design and industrial application of efficient visible light induced TiO2 composite photocatalyst, the relationship between structure and activity is investigated systematically on the basis of the theoretical analysis and calculation, synthesis law is revealed.

减灭药品及个人护理用品(PPCPs)潜在环境威胁的新技术日益受到重视。因具有化学稳定性高、无毒等优点，TiO2被广泛应用于光催化降解PPCPs。然而，TiO2存在仅能被紫外光激发、低量子效率等不足。因此，如何利用TiO2太阳光催化降解PPCPs是亟待解决的环境材料问题。. 拟以取代Dawson结构HPC@TiO2分子印迹可见光催化剂的结构调控与降解PPCPs性能增强为研究对象，用复分解、嵌入改性法等合成稀土（过渡）金属取代多原子（抗衡阳离子）可见光响应HPC；用溶胶凝胶法等制备分子印迹TiO2；经浸渍法等构筑取代Dawson结构HPC@TiO2分子印迹可见光催化剂，用XRD等进行表征，以可见光降解PPCPs乙酰水杨酸、对羟基苯甲酸乙酯为探针反应考察其光催化活性。探索可见光响应高活性TiO2复合光催化剂的制备方法，结合理论分析计算，系统研究构效关系，揭示合成规律，为其设计及工业应用奠定基础。

药品和个人护理用品(PPCPs)具有较强的生物活性和生物降解缓慢的特点，对环境、生物和人类健康能造成持久性影响和危害。TiO2因具有无毒、稳定性好等优点成为了光催化去除水体中PPCPs等有机污染物的研究热点。然而，TiO2存在仅能被紫外光激发、量子效率低等不足。因此如何提高TiO2的量子效率和拓宽其光吸收范围是光催化降解PPCPs增强的关键。.本项目以取代Dawson结构杂多化合物(SD-HPC)、分子印迹TiO2(MT)为构筑单元，利用SD-HPC的电荷受体作用，将光生电荷有效分离，提高光催化量子效率，并利用SD-HPC对可见光的吸收来扩展复合光催化剂的光吸收范围，同时利用MT光催化剂的印迹空腔，对PPCPs产生富集作用，进而提升SD-HPC@MT复合光催化剂的效能。项目重点合成了Co3P2W18O62@TiO2、K17[Ce(α2-P2W17O61)2]@TiO2分子印迹可见光催化剂，获得了SD-HPC@MT分子印迹可见光催化剂的合成方法与规律。详细研究了不同SD-HPC@MT分子印迹可见光催化剂的光催化性能，研究了SD-HPC在复合光催化剂中对其光催化活性的影响，SD-HPC@MT分子印迹可见光催化剂的重复使用性能，明确了SD-HPC@MT的光催化机理。通过将六种SD-HPC@MT分子印迹可见光催化剂分别用于光催化降解PPCPs，研究了取代金属种类、数量对分子印迹SD-HPC@MT可见光催剂光催化降解PPCPs性能的影响。.在此基础上，研究了SD-HPC组成、含量对SD-HPC@MT光催化剂降解PPCPs性能的影响，进而研究了分子印迹SD-HPC@MT可见光催化剂组成、微观结构与光催化效能之间的构效关系。同时还研究了pH、H2O2及光催化剂用量等因素对不同SD-HPC@MT光催化活性的影响，进一步优化了光催化效能，优化后的PPCPs去除率最高可达到97.3%。SD-HPC@MT中SD-HPC的引入能够抑制光生电子复合，而过量的SD-HPC能形成电子陷阱，降低光催化活性。分子印迹空穴能够增加PPCPs的吸附，提升光催化效能。本项目的实施可为SD-HPC@MT分子印迹可见光催化剂的可控合成提供新的思路，同时为降解PPCPs用高活性TiO2可见光催化剂的设计、应用提供理论依据与技术支撑。

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