【作者】 王晓辉；

【导师】 杨建军； 金振声；

【作者基本信息】 河南大学 ， 分析化学， 2004， 硕士

【摘要】 去年全国人民面临“非典型性肺炎”的侵害，为了净化室内空气，许多以杀菌灯为光源的光催化空气净化器应运而生，这就产生了室内污染物---臭氧，臭氧对人身体具有很大的危害性，所以研究空气中杀菌灯产生的臭氧和臭氧的消除工作就很具有实际意义。 本文用流动型反应装置，对8W杀菌灯（λ=253.7nm）辐照空气时产生的臭氧进行了研究。发现在一定条件下当空气与杀菌灯接触大约7s时，就有超出0.33μg／L的臭氧产生。随着空气流速的减小，产生的臭氧的量随之变大。采用兰州化物所生产的臭氧分解催化剂对臭氧的消除进行了研究，发现当体积空速小于1.1×10⁵h^-1时，臭氧可以降解到安全范围。 通过比较臭氧在四种不同产地TiO₂（舟山TiO₂、泰州TiO₂、P-25和fluka TiO₂）表面的分解性能，发现其光催化消除臭氧的活性顺序是P-25＞舟山TiO₂＞泰州TiO₂＞fluka，然后在活性较高、价格较低的舟山TiO₂上分别负载了0.1％的Pt、Au和Ag，发现它们对臭氧消除率随着反应时间的延长而不断下降，经过几十个小时以后基本达到稳定，其活性及稳定性研究结果为：Au／TiO₂＞Ag／TiO₂＞Pt／TiO₂＞TiO₂。然后又在舟山TiO₂上分别负载了0.1％和1％质量的Au,评价结果为：0.1％Au（wt）／舟山TiO₂＞1％Au（wt）／舟山TiO₂。 舟山TiO₂和1％Au（wt）／舟山TiO₂反应前后的XPS谱图结果显示：两个催化剂反应100h后的氧钛比都比反应前增加约30％，这可能是因为（1）在Au／舟山TiO₂河南大学分析化学专业二零零一级硕士学位论文:摘要消除臭氧的过程中，TIOZ表面发生了重构，Ti原子的配位数发生变化，因而氧钦比增加;（2）反应过程中表面吸附了02一，从而氧钦比也增加。这可能也是它们对臭氧消除率在初始阶段随反应时间的延长而不断下降的原因。 活性较高的0.1%Au（wt）/舟山Tiq进行了400h的寿命评价，臭氧的消除率开始的时候一直下降，到250h小时以后基本达到稳定，且能保持较高的活性，所以可以初步作为有效消除臭氧的高活性、长寿命、低成本的光催化剂。更多还原

【Abstract】 Many people were hurted by SARS which spread all over the country .To clean the indoor air many air-cleaning instruments with the bactericidal lamp were produced, but it can generate a harmful gas-ozone, so it is necessary to design a kind of more safe and effective air-cleaning instrument ,and it has practical significance to study the generation of O3 under bactericidal lamp illumination and ozone decomposition .In air, the generation of O3 under bactericidal lamp illumination was studied with a flow-type reactor at room temperature. The results showed the concentration of ozone generated went beyond 0.33ug/L (allowable concentration) when the contact time for 8W bactericidal lamp was about more than 7s, and the ozone concentration increased with the decreasing air flow rate. The catalytic decomposition of ozone was also studied with the use of carbon-supported MnO2-Fe2O3 catalyst. The results showed ozone could be decomposed to below 0.28|j.g/L when the volume space velocity was less than 1.1x105h-1.Ozone decomposition was investigated over four kinds of TiO2 (Zhou Shan TiO2, Tai Zhou TiO2,P-25,fluka)which were bought from different places ,results of this study indicated that the performance of their photodecomposition ozone was P-25> Zhou Shan TiO2 > Tai Zhou TiO2 >fluka. Then we prepared Metal/ Zhou Shan TiO2 using the impregnation . Comparison experiment of their stability on ozone decomposition was done with the same weight of Au,Ag and Pt supported on Zhou Shan TiO2. Results of this study indicated that the ozone photodecomposition activity of them decreased with the prolonged reaction time , and nearly reached a stable value at last. 0.1%Au(wt)/ Zhou Shan TiO2 was found to be of high activity .Their order of photodecompositionozone was Au/ TiO2 > Ag/ TiO2 >Pt/ TiO2.This showed the activity of photocatalysis was increased when Au,Ag and Pt were loaded onto Zhou Shan TiO2-Then 0.1%Au(wt)/ Zhou Shan TiO2 and 1%Au(wt)/ Zhou Shan TiO2 were prepared with the same method ,and their activity were studied too. Results indicated: 0.1%Au(wt)/ Zhou Shan TiO2>1%Au(wt)/ Zhou Shan TiO2.XPS spectra of Zhou Shan TiO2 and l%Au(wt)/ Zhou Shan TiO2 showed that the atomic ratio of oxygen and titanium after reaction was 30% more than that before reaction, the reason may be as follows: First, the TiO2 surface reconstructed during the reaction between TiO2 and ozone, the coordinator of Ti changed. Second, O2- was adsorped onto the TiO2 surface. So the ratio of oxygen and titanium increased.The lifetime was studied about the 0.1%Au(wt)/ Zhou Shan TiO2 , we find its activity of decomposing ozone decreased during the reaction ,but it kept a stable activity after the reaction went on for 250h . So 0.1%Au(wt)/ Zhou Shan TiO2 may be the right catalyst in the designing air-cleaning instrument with its lower lost ,ionger service and higher activity.更多还原