Critical role of tetracycline's self-promotion effects in its visible-light driven photocatalytic degradation over ZnO nanorods.

Zinc oxide (ZnO), which is widely applied for ultraviolet-light driven photocatalysis, has no activity in visible-light photocatalytic process due to its large band gap of ∼3.2 eV. Herein, however, we demonstrated the multiple self-promotion effects of tetracycline as band adjuster, photo-sensitizer, and charge transfer promoter for ZnO nanorods, realizing its visible-light photocatalytic degradation with an excellent removal efficiency up to 91.1% within only 2 h. Besides, the influence of complex realistic factors on this unique process was evaluated together with tests with realistic water matrices. Furthermore, the active species and degradation products were identified. Both acute and developmental toxicities were found to be reduced as the degradation proceeds. These results pave the path for the brand-new self-driven visible-light photocatalysis. [Display omitted] • It is the first time to report visible-light photo-degradation of TC over ZnO. • TC acts as reactant, band adjuster, photo-sensitizer, and charge transfer promoter. • Photo-degradation of various antibiotics was comparatively studied. • Reaction pathway was revealed with toxicity reduced as degradation proceeds. • This process shows a great promise for practical application. [ABSTRACT FROM AUTHOR]