臭氧光催化转化的基础研究

The negative influence of ozone (O3) is increasingly prominent, due to its strong oxidizing property. The environment pollutions caused by O3 threats seriously to people's life safety and health. Especially, in closed environment where most of people appear frequently, such as subway cars, aircraft cabins, and so on, which is difficult to rapid degradation. Therefore, how to remove O3 efficiently and conveniently becomes an important research subject. In order to realize that the degradation of O3rapidly and effectively, a series of new type of precious metal modification (001) TiO2/Gn composite photocatalysts will be prepared and be applied to the treatment of high concentration of O3 in closed environment. The main research contents: Preparation of precious metal modification (001) TiO2/Gn composite photocatalysts step by step via modified Hummer method, hydrothermal method and chemical reduction method, respectively. XRD, SEM, TEM, XPS, IR, DRS, UV, and NMR are used to characterize analyze the composite materials comprehensively. The coordination mechanism among precious metal, (001) TiO2 and Gn will be investigated in detail. Design and build photocatalytic reactor, investigate the photocatalyst degradation of O3 by the composite photocatalysts. The efficiency of photocatalytic degradation will be tested. The effects of Gn dosage, the crystal plane (001) of TiO2, and precious metals type on the efficiency of photocatalyst degradation of O3 were also studied. The reaction mechanism of photocatalyst degradation of O3 by the precious metal modification (001) TiO2/Gn will be analyzed.

具有极强氧化性的臭氧（O3）给人类生活带来日益负面影响，尤其在西藏高海拔地区室内环境、活动频繁的车厢，以及高空飞行的客机坐舱等封闭环境中，随海拔浓度增高的O3难以实现自降解而给人们的健康构成持续威胁和影响，因此高效便捷地去除空气中O3在西藏意义重大。本项目研究制备一系列新型贵金属改性(001)TiO2/Gn复合光催化剂，利用气相光催化反应器，实现封闭环境空气中O3安全快速降解。采用改性Hummer法和水热法分步制备贵金属改性(001)TiO2/Gn复合光催化剂；通过XRD、TEM、XPS、IR、DRS、UV、NMR表征方法对贵金属改性(001)TiO2/Gn复合材料进行表征和分析，研究三者协调作用机理。在光催化反应器中采用复合光催化剂降解处理O3，测定降解效率，研究Gn用量、TiO2（001）晶面、贵金属类型等对光催化效率的影响规律，实现光催化降解臭氧反应机理和动力学的基础研究。

本研究采用改性Hummer法制备氧化石墨作为Gn前驱物，通过加入酞酸四丁酯以传统溶胶凝胶法将Gn与TiO2复合，并通过改变氧化石墨投加量制备出不同C/Ti比的TiO2-Gn复合材料。采用XRD、拉曼光谱、SEM、TEM等表征所制备材料的晶相组成及表面形貌，验证了所制备的复合光催化剂为片层态Gn为载体上附着以锐钛矿为主晶相的TiO2纳米颗粒材料。并用亚甲基蓝溶液分别试验了不同C/Ti比复合材料的吸附性能和光催化活性，并分析反应机理。选出光催化活性最高的含C量为1.5wt%的TiO2-Gn复合材料进行光催化降解O3研究。 .本研究选用光催化技术手段，自行设计搭建气相光催化反应器，对O3进行光催化降解实验研究。结果表明所制备的TiO2-Gn复合光催化材料对O3的降解性能显著优于纯TiO2，分别考察了反应时间和初始O3浓度对复合材料光催化降解活性的影响。在本实验条件下，O3浓度为0.150ppm- 0.200ppm时，复合光催化剂受紫外光激发60min的光催化降解率为66.12%，初始O3浓度为0.950ppm-1.000ppm时，其光催化降解率约为77%，较低浓度时(0.100ppm-0.150ppm)，O3去除率也能达到45.45%。此外，本研究还探讨了光催化材料的重复使用性能，复合光催化剂重复使用4次，其对O3的光催化降解率仅下降2.53%。根据实验数据和结论，分析了TiO2-Gn复合光催化剂降解O3的反应机理。