Photodegradation of ciprofloxacin in water using silver nanostructures

Abstract

Contamination of aquatic resources with antibiotics poses a threat to the environment and human health, leading to the increase of antimicrobial resistance, which is predicted to be the leading cause of death by 2050. Conventional water treatment systems are often ineffective in removing antibiotics and the implementation of more efficient methods, such as photocatalysis, is an important step forward to mitigate this problem. Nanomaterials have shown efficiency as photocatalysts in the degradation of organic pollutants, due to their high surface area/volume ratio. Among these nanomaterials are silver nanoparticles, which are easy to prepare, low cost, and have shown good performance in photocatalysis. In this study, silver nanospheres (AgNSps) and nanoplates (AgNPls) were prepared for the treatment of water contaminated with the antibiotic ciprofloxacin (CIP), under simulated sunlight irradiation. Results revealed that all AgNPs prepared were efficient in the photodegradation of CIP, in PBS and river water matrix, achieved a degradation efficiency higher than 77 % in 5 min of irradiation. Moreover, the photodegradation rate constant was enhanced in the presence of the catalyst, from 0.178 ± 0.007 min−1 to 0.47 ± 0.05 and 0.51 ± 0.09 min−1, with AgNSps and AgNPls, respectively, in river water. Thus, this work demonstrates that AgNPs are promising photocatalysts for solar-driven removal of antibiotics from water, enabling the treatment of contaminated waters.

Keywords

• Nanomaterials
• Photocatalysis
• Antibiotics' removal
• Water treatment