【摘要】 以锐钛矿、金红石及混晶TiO2作光催化剂,以活性艳红X-3B及苯酚作模型污染物,研究了TiO2的晶型对其可见光催化性能的影响.结果表明:在Vis/O2条件下,以锐钛矿或混晶TiO2作光催化剂,反应80 min对活性艳红X-3B的降解率近100%,金红石型TiO2的则不到15%;在Vis/H2O2条件下,三种光催化剂均能降解苯酚,且金红石型TiO2显示更高的催化活性,反应180 min对苯酚的降解率达54%.通过对反应体系的荧光光谱分析显示,反应过程涉及.OH自由基的产生和参与;在TiO2可见光催化反应过程中,由锐钛矿型TiO2经一系列复杂反应产生H2O2,生成的H2O2在TiO2表面形成活性位吸附,从而拓宽TiO2的光吸收范围至可见光区,再在可见光激发下产生.OH自由基等活性物种而对污染物起降解作用.更多还原

【Abstract】 The effects of crystalline structure,anatase,rutile and mixing crystal,on the visible-light photocatalytic performance of TiO₂ were studied with reactive red X-3B and phenol as model pollutants.The results showed that the degradation ratio of reactive red X-3B after 80 min reaction could be as high as 100% when using anatase or mixing crystal TiO₂ as photocatalyst under the condition of Vis/O2,but the degradation ratio was less than 15% when using rutile TiO₂ as photocatalyst.Phenol could be degraded under the condition of Vis/H2O2 by any of the three photocatalysts;rutile form exhibited a better photocatalytic activity,and its degradation ratio could be 54% after 180 min reaction.Fluorescence spectrum analysis indicates that the reaction process is predominated by the generation of ·OH radicals in the system.In the process of TiO₂ visible-light photocatalysis,hydrogen peroxide is generated by anatase TiO₂ from a series of complex reactions,and the generated hydrogen peroxide is absorbed on the surface of TiO₂ to form active species,which is responsible for the generation of ·OH radicals and the degradation of organic pollutants under visible light irradiation.更多还原