Pd-TiO_(2)光催化高效降解有机卤代污染物

Highly efficient degradation of organohalides pollutants by Pd/TiO_(2) photocatalyst

环境中有机卤代污染物具有浓度低、难降解、高毒性和生物富集性等特点,因此对有机卤代污染物的环境行为的理解和去除技术的研究具有非常重要的意义。Pd/TiO_(2)光催化剂在卤代有机污染物的降解过程中表现出高效的催化活性。研究表明,光催化降解活性同芳环电子密度及其取代基性质有密切的联系;给电子基团对于光催化还原脱卤反应有利;相同条件下,脱溴反应速率高于脱氯反应速率。

The recalcitrant organohalides pollutants in the environment have the characteristics of low concentration,hardly degradation,extremely toxic and accumulation in the biosphere.The research of the environmental behaviors of the organohalides and the degradation techniques is necessary.Pd/TiO_(2) photocatalyst is highly active for the organohalides pollutants degradation.Present study shows the degradation performance is dependent on the electron density of the aromatic ring as well as the properties of the substation groups.The electron-donating groups on the aromatic ring contribute positively to the cleavage of the carbon-halogen bond.Meanwhile,the debromination reaction rate is greater than that of dechloridation under the same condition.