Excellent photocatalytic degradation of tetracycline over black anatase-TiO2 under visible light

As an emerging semiconductor different from regular white TiO 2 , black TiO 2 has attracted intensive attention on visible light driven photocatalysis for degrading dyes, but rarely for degradation of antibiotics. In this study, black anatase-TiO 2 was demonstrated to be an effective catalyst for tetracycline (TC) visible light photodegradation. 66.2% removal efficiency of TC was achieved over black TiO 2 under visible light illumination, while white TiO 2 and N-doped TiO 2 exhibited 43.4% and 59.6% removal efficiencies, respectively. Furthermore, only ⋅O 2 − radicals played an important role in TC photodegradation over white TiO 2 , whereas both ⋅O 2 − and h + were responsible for the degradation over black TiO 2 and N-doped TiO 2 . Different from white TiO 2 for visible light photocatalytic TC degradation that follows photosensitization, the visible light photodegrataion over black TiO 2 is due to photoexcitation.