Solar photocatalytic degradation of diclofenac aqueous solution using fluorine doped zinc oxide as catalyst

• Published in: Journal of photochemistry and photobiology. A, Chemistry. Chemistry., 2020-03, Vol.391, p.112364, Article 112364
• Main Authors: Rueda-Salaya, L., Hernández-Ramírez, A., Hinojosa-Reyes, L., Guzmán-Mar, J.L., Villanueva-Rodríguez, M., Sánchez-Cervantes, E.
• Format: Article
• Language: English
• Subjects: Diclofenac solution; Fluorine doped ZnO; Heterogeneous photocatalysis; Solar radiation
• ISSN: 1010-6030; 1873-2666
• DOI: 10.1016/j.jphotochem.2020.112364

Eschematic representation of DCF degradation using fluorine doped zinc oxide under solar radiation [Display omitted] •ZnO photocatalysts with different amounts of fluorine incorporated were prepared by sol-gel technique.•Box Behnken combined with Response Surface Methodology was used to optimize the photocatalytic process.•Almost complete mineralization (90%) of DCF emergent pollutant was achieved using F doped ZnO.•This system represents an environmentally friendly process due to the use of solar light. The photocatalytic degradation of a sodium diclofenac (DCF) solution (10 mg/L) under simulated solar radiation was evaluated using a ZnO semiconductor modified by the incorporation of 10, 15, and 20 wt.% fluorine (ZnO-F10, ZnO-F15 and ZnO-F20). The ZnO-F catalysts were synthesized by the sol-gel method using zinc acetate as a precursor of zinc oxide and NH4F as a fluorine source. The photocatalytic performance of the F-doped ZnO material was compared to that of bare ZnO. The obtained photocatalysts were characterized using X-ray diffraction (XRD), Scanning electron microscopy with Energy dispersive spectroscopy (SEM-EDS) and X-ray photoelectron spectroscopy (XPS) techniques. The Brunauer-Emmett-Teller (BET) surface area, pH of zero charge (pHpzc), and band gap of the solids were also evaluated. An experimental Box-Behnken design combined with response surface methodology was applied to establish the optimal conditions for the photocatalytic degradation of the DCF solution. Complete DCF degradation, total release of chloride ions, and approximately 90% mineralization were achieved during degradation of the drug at an accumulated energy of 400 kJ/m2 under the optimized experimental conditions (1 g/L of ZnO-F20 catalyst with the pH of the DCF solution maintained at 6.5).