Photocatalytical removal of fluorouracil using TiO2-P25 and N/S doped TiO2 catalysts: A kinetic and mechanistic study

Α Koltsakidou; M Antonopoulou; Ε Εvgenidou; I Konstantinou; A E Giannakas; M Papadaki; D Bikiaris; D A Lambropoulou

doi:10.1016/j.scitotenv.2016.08.208

Photocatalytical removal of fluorouracil using TiO₂-P25 and N/S doped TiO₂ catalysts: A kinetic and mechanistic study

Sci Total Environ. 2017 Feb 1:578:257-267. doi: 10.1016/j.scitotenv.2016.08.208. Epub 2016 Nov 14.

Authors

Α Koltsakidou¹, M Antonopoulou², Ε Εvgenidou¹, I Konstantinou³, A E Giannakas², M Papadaki², D Bikiaris¹, D A Lambropoulou⁴

Affiliations

¹ Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
² Department of Environmental and Natural Resources Management, University of Patras, 30100 Agrinio, Greece.
³ Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece.
⁴ Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece. Electronic address: dlambro@chem.auth.gr.

PMID: 27856058
DOI: 10.1016/j.scitotenv.2016.08.208

Abstract

In the present study, the photocatalytic activity of TiO₂-based photocatalysts toward degradation and mineralization of the anti-cancer drug 5-fluorouracil (5-FU) in aqueous phase was investigated under simulated solar and visible irradiation. Commercial TiO₂ (P25) and N/S-doped TiO₂ catalysts synthesized by a simple sol-gel method were used as photocatalysts. TiO₂ P-25 was found to be the most photoactive catalyst for the removal of 5-FU, under simulated solar irradiation. Among N/S-doped TiO₂ catalysts, the one with molar Ti:N/S ratio equal to 0.5 was the most efficient under simulated solar irradiation. In contrast, under visible irradiation the catalyst with equimolar Ti:N/S ratio showed the highest performance for the removal of 5-FU. Scavenging experiments revealed that HO radicals and h⁺ were the major reactive species mediating photocatalytic degradation of 5-FU using TiO₂ P-25 and N/S-doped TiO₂ catalysts, under simulated solar irradiation. On the other hand, the essential contribution of ¹O₂ and O₂^- in the degradation of 5-FU under visible light was proved. The transformation products (TPs) of 5-FU, were identified by LC-MS-TOF suggesting that defluorination followed by hydroxylation and oxidation are the main transformation pathways, under all the studied photocatalytic systems.

Keywords: 5-Fluorouracil; N/S-doped TiO(2) catalysts; Scavengers; TiO(2); Transformation products.

MeSH terms

Catalysis
Fluorouracil / isolation & purification*
Light
Photolysis*
Titanium / chemistry*

Substances

titanium dioxide
Titanium
Fluorouracil