Degradation of Orange II over sulforhodamine B (SRB) sensitized TiO_2 under visible irradiation

摘要

Sensitization technology as a surface modification technology has been used to modify TiO_2 to enlarge its sunlight utilization efficiency. In this study, polymerization reaction of acrylamide was used to form polymer film on the surface of TiO_2 (P25), and dye molecular of SRB was fixed in the web of acrylamide polymer at the same time, so sulforhodamine B (SRB) sensitized P25 was obtained. Compared with pure P25, the response of SRB sensitized P25 to both UV and visible lights was enhanced. And it can degrade Orange II, SRB, and RhB with less time; the optimal amount of catalyst for Orange II was 1.5 g/L. When the catalyst was used for second and third time, its catalyst activity was declined, but still better than P25 under otherwise identical conditions. Active species were estimated by adding different scavengers to the photocatalytic system, and it was found that the degradation of Orange II over SRB sensitized P25 mainly involved the mechanism of ?OH and singlet oxygen.