Photosensitized Oxidation of Emerging Organic Pollutants by Tetrakis C_(60) Aminofullerene-Derivatized Silica under Visible Light Irradiation

摘要

We recently reported that C_(60) aminofullerenes immobilized on silica support (aminoC?,/silica) efficiently produce singlet oxygen (1O_2) and inactivate virus and bacteria under visible light irradiation.1 We herein evaluate this new photocata-hrst for oxidatnc degradation of It emerging organic contaminants, including pharmaceuticals such as acetaminophen, carbamazepine, dmetidine, propranolol, ranitidine, gulfisoxazole, and trimethoprim, and endocrine ditruptors such as bisphenol A and pentacblorophenol Tetrakis aminoC_(60)/sffica degraded phar-maceuticah under visible light irradiation faster than common semiconductor photocatalytts such as platinized WO_3 and carbon-doped TiO_2. Furthermore, amtaoC_(60)/silica exhibited high target-specmcirr without significant interference by natural or-ganic matter. AmutoC_(60)/silica was more efficient than unsupported (voter-suspended) C_(60) aminofullerene. This was attributed to bneticaBy enhanced O_2 production after immobilaation, which reduces agglomeration of the photocatalyst, and to adsorption of Pharmaceuticals onto the silica support, which increases exposure to O_2 near photocatarytic sites. Removal emciency increased with pH for contaminants with a phenolic moiety, such as bisphenol A and acetaminophen, because the electron-rich phenolates that form at alkaline pH are more vulnerable to singlet orygenabon.