Enhanced photocatalytic degradation of sulfamethoxazole by deposition of Au, Ag and Cu metallic nanoparticles on TiO2

• Published in: Environmental technology Vol. 39; no. 18; pp. 2353 - 2364
• Main Authors: Zanella, Rodolfo, Avella, Edwin, Ramírez-Zamora, Rosa María, Castillón-Barraza, Felipe, Durán-Álvarez, Juan C.
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 17-09-2018; Taylor & Francis Ltd
• Subjects: Antibiotics; by-products; Byproducts; Catalysts; Catalytic activity; Copper; Gold; Irradiation; Mineralization; Nanoparticles; noble metals; Photocatalysis; Photodegradation; Photolysis; Silver; Simulation; Sulfamethoxazole; Sunlight; Titanium dioxide; Toxicity; Ultraviolet radiation
• ISSN: 0959-3330; 1479-487X
• DOI: 10.1080/09593330.2017.1354926

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.