Ciprofloxacin degradation with a defective TiO2-x nanomaterial under sunlight

TiO2 nanoparticles obtained by microwave-assisted hydrothermal synthesis were subjected to facile post-processing based on vacuum annealing. The resulting defective (TiO2-x) material showed extended light absorption in the visible range, enhancing sunlight compatibility. Structural and optical characterization point to the arising of an Urbach tail as the main reason. TiO2-x was then employed as photocatalyst for the inactivation of ciprofloxacin, an emerging environmental threat and source of antimicrobial resistance, under sunlight. TiO2-x performed significantly better than its parent compound and mechanistic analysis of the degradation pathway indicates that this material is a promising candidate for solar treatment of fluoroquinolones residues in water.