Photocatalytic oxidation of cytostatic drugs by microwave‐treated N‐doped TiO₂ under visible light

Abstract

Abstract BACKGROUND 5‐Fluorouracil is one of the most commonly used cytostatic drugs worldwide. However, the toxicity and persistence of 5‐fluorouracil in the environment have recently received considerable attention. In this study, 5‐fluorouracil removal was performed by photocatalytic oxidation with microwave‐treated N‐doped TiO 2 under visible light. RESULTS The microwave‐treated N‐doped TiO 2 removed 5‐fluorouracil with a higher degradation efficiency than N‐doped TiO 2 synthesized with the traditional thermal treatments. The most efficient N‐doped TiO 2 ( N6 ) was synthesized using 1 M NH 4 OH pre‐immersion and a 3 h 180°C microwave treatment, followed by 55°C calcination for 6 h. The photocatalytic degradation of 5‐fluorouracil achieved 88.8% removal within 20 h of treatment by N6 under visible light, which is higher than that obtained by Degussa P25 TiO 2 (61.5%). Higher concentrations of NH 4 OH and longer calcination times resulted in decreased 5‐fluorouracil degradation; the particle size of the synthesized N‐doped TiO 2 increased after calcination. The surface area decreased while the pore volume and pore size increased after synthesis. Furthermore, the basicity of the sites on the synthesized N‐doped TiO 2 decreased after calcination. CONCLUSION This study, for the first time, reported that microwave‐assisted treatment for N‐doped TiO 2 synthesis effectively removed 5‐fluorouracil and cyclophosphamide compared with traditional thermal treatment. © 2014 Society of Chemical Industry