Bi-B-TiO2-based photocatalytic decomposition of cytostatic drugs under simulated sunlight treatments

Abstract

Abstract The Bi-B co-doped TiO 2 photocatalysts were prepared via a simple sol-gel method. Initially, the photocatalysts were applied to decompose ifosfamide (IF). 3Bi-B-TiO 2 was found to be the most effective photocatalyst with regard to the cytostatic drug decay; it was also characterized by good sedimentation properties. For the constant concentration ratio of [IF]:[catalyst], this photocatalyst was more effective in the removal of IF at low drug concentrations. The study employing scavengers, i.e. F − ions and isopropanol demonstrated that the modification of TiO 2 with Bi and B co-dopants has a negative effect on the generation of OH free radicals. The decomposition of the studied cytostatic drug was most likely connected to the reaction with OH ads radicals generated at the catalyst surface. The quantitative and qualitative determination of IF intermediates during the photocatalytic decomposition in the presence of 3Bi-B-TiO 2 showed that dechlorination was a more advanced process compared to the oxidation of organic matter. Lastly, other cytostatic drugs such as, cyclophosphamide (CP), 5-fluorouracil (5-FU) and imatinib (IMA) decomposed in the presence of 3Bi-B-TiO 2 under artificial sunlight and visible light irradiation. The rate and efficiency of photocatalytic decay of the aforementioned cytostatic drugs increased in the following order: CP ≈ IF