Chinese Journal of Catalysis ›› 2015, Vol. 36 ›› Issue (11): 1818-1824.DOI: 10.1016/S1872-2067(15)60967-6

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Kinetics and mechanism of thymine degradation by TiO2 photocatalysis

L. Elsellamia,b,c, N. Hafidhib, F. Dappozzea, A. Houasb, C. Guillarda   

  1. a IRCELYON, CNRS UMR 5256/Université Lyon 1, 2 Avenue Albert Einstein, 69626 Villeurbanne Cedex, Lyon, France;
    b Research Unit Catalysis and Materials for the Environment and Processes URCMEP (UR11ES85), University of Gabes, University Campus Hatem Bettahar-Erriadh-6072 Gabes, Tunisia;
    c Higher Institute of Applied Sciences and Technology of Gabes, University of Gabes, Tunisia
  • Received:2015-08-08 Revised:2015-08-24 Online:2015-11-02 Published:2015-11-02
  • Contact: L. Elsellami. 电话: +216-75-392600; 传真: +216-75-392241; 电子信箱: elsellami_leila@yahoo.fr
  • Supported by:

    This work was supported by The French Institute of Tunisia and University of Gabes, Tunisia (Scientific Stay High Level 2015).

Abstract:

The advanced oxidation processes were examined toward the degradation of thymine (C5H6N2O2), a type of nucleic acid from the pyrimidine family. As observed, the photodegradation of thymine over TiO2 photocatalyst was rapid and significant in aqueous solution under UV irradiation. Different parameters were studied, including the adsorption of thymine onto TiO2 photocatalyst, the kinetics of degradation, and the effect of pH on the photocatalytic properties of thymine degradation. Additionally, the mineralization of the products obtained upon thymine photodegradation was studied. The disappearance and mineralization rates of thymine during the photocatalytic process were also compared and discussed. The mineralization of nitrogen was also investigated, and the identification of the intermediate products was established. Finally, electronic density calculations were used to propose possible chemical pathways for the photodegradation of thymine over TiO2 photocatalyst under UV irradiation.

Key words: Titania, Photocatalysis, Thymine, Photomineralization, Frontier electron density