| 초록 |
Polyoxometalates (POMs) as a homogeneous photocatalyst and semiconductor oxide TiO2 as a heterogeneous photocatalyst share many aspects of similarity in their operating mechanisms. In this study, we compared photocatalytic inactivation of pathogenic E. coli using POM and TiO2 in aqueous solution. Almost all the initial E. coli (5 X 107 cell/ml) were inactivted with 40 min in the presence of both POM and TiO2, but the POM-mediated inactivation was faster than that with TiO2 under the experimental conditions employed in this study. Photocatalytic inactivation of E. coli was more efficient by free H4O40SiW12 or Mo12O40P than by TiO2. Kinetic studies using tert-butyl alcohol or methanol as an OH radical scavenger suggested that OH radicals are dominant photooxidant in photocatalyst inactivation. In particular, the biocidal action of the photocatalyst has been accepted that reactive oxygen species (ROS) and OH radicals play the role. |
