Combined adsorption process and photocatalytic degradation of some commercial herbicides over N-doped TiO₂ particles supported on recyclable magnetic hexagonal mesoporous silica

ABSTRACT

Magnetic hexagonal mesoporous silica (magnetic HMS) containing N-doped TiO₂ was prepared by hydrothermal method and used for the removal of trifluralin, 2,4-dichlorophenoxyacetic acid, and glyphosate herbicides at the presence and absence of UV/visible lights. The prepared samples were found as efficient for the removal of the herbicides and easily recyclable after treatment by UV irradiation. A red shift effect by nitrogen doping was also observed in the prepared samples resulting photocatalytic activity at the presence of visible light. Kinetic studies indicated that the photodegradation followed as the first order and k_UV ≈ 10k_vis. The results also showed synergetic effects between the adsorption of herbicides on the surface of magnetic HMS and photoreactions over N-doped TiO₂ species.

KEYWORDS:

• Photocatalyst
• nitrogen doping
• herbicide
• titanium oxide
• HMS

Acknowledgements

This research was supported by Qaemshahr Branch of Islamic Azed University (IAU) and the authors thank Mrs. Azimi for her assistance in Laboratory of Analysis at IAU University. The authors also thank Dr. Babanejad for HPLC analysis at Mazandaran University of Medical Sciences.