| Autor: |
Zanella R; a Centro de Ciencias Aplicadas y Desarrollo Tecnológico , Universidad Nacional Autonoma de Mexico, Circuito Exterior S/N, Ciudad Universitaria , Coyoacan , Mexico., Avella E; a Centro de Ciencias Aplicadas y Desarrollo Tecnológico , Universidad Nacional Autonoma de Mexico, Circuito Exterior S/N, Ciudad Universitaria , Coyoacan , Mexico., Ramírez-Zamora RM; b Instituto de Ingeniería , Universidad Nacional Autonoma de Mexico , Coyoacan , Mexico., Castillón-Barraza F; c Centro de Nanociencias y Nanotecnología , Universidad Nacional Autónoma de México , Ensenada , México., Durán-Álvarez JC; a Centro de Ciencias Aplicadas y Desarrollo Tecnológico , Universidad Nacional Autonoma de Mexico, Circuito Exterior S/N, Ciudad Universitaria , Coyoacan , Mexico. |
| Abstrakt: |
Mono- (Au, Ag and Cu) and bi-metallic (Au-Ag and Au-Cu) nanoparticles were deposited on TiO 2 and tested for the photocatalytic degradation of sulfamethoxazole using either UV-C or simulated sunlight. The optimal loading of metallic nanoparticles was determined as 1.5 wt% for Au and Ag, and 1.0 wt% for Cu. In the case of bi-metallic nanoparticles, only the ratio 1:0.5 wt% for both Au-Ag and Au-Cu was tested. In experiments using UV-C light, the highest degradation performance was found for Ag/TiO 2 , while bi-metallic nanoparticles supported on TiO 2 also showed increased photocatalytic activity compared with unmodified TiO 2 . In simulated sunlight irradiation tests, Au/TiO 2 showed to be the most efficient material. Complete mineralization of sulfamethoxazole was achieved when surface-modified materials were tested in both UV-C and simulated sunlight experiments. Photolysis was efficient to fully degrade sulfamethoxazole, although mineralization was lower than 10% for both luminic sources. The main by-products of sulfamethoxazole were determined in photolysis and photocatalysis tests using UV-C light, and degradation paths were proposed. By-products showed non-toxicity and low antibiotic activity. Reuse of the catalysts upon three reaction cycles did not result in the loss of activity. |
