Tetracycline sensitizes TiO2 for visible light photocatalytic degradation via ligand-to-metal charge transfer

Treatment of antibiotics contaminated water remains a global environmental challenge. In this study, tetracycline (TC) was found to effectively sensitize pure TiO 2 for visible light photocatalytic degradation via a ligand-to-metal charge transfer mechanism. The sensitization was attributed to the formation of TC-TiO 2 complex and the overlap of the molecular orbitals of TC and the conduction band of TiO 2 . The intermediate degradation products of TC, however, did not sensitize TiO 2 , which was the reason for the low mineralization rate. Nevertheless, our results showed that the intermediate degradation products of TC had significantly reduced bactericidal effects and less induction of antibiotic-resistance genes (ARGs). This study showcases an effective treatment of antibiotics-containing wastewater using the most common photocatalyst TiO 2 with reduced risk in the spread of ARGs. Tetracycline sensitized pure TiO 2 for visible light photocatalytic degradation via ligand-to-metal charge transfer mechanism. The intermediate degradation products of TC, however, did not sensitize TiO 2 .