Solar light driven magnetic-photocatalyst nanohybrid and photocatalytic degradation of pharmaceutical pollutants

Pharmaceutical pollutants substantially affect the environment; thus, their treatments have been the focus of many studies. In this regard, photocatalytic degradation ofpharmaceutical pollutants in the wastewater using dispersed semiconductor nanophotocatalysts under solar light has a number of advantages such as high activity, cost effectiveness and utilization of free solar energy. However, it is difficult to recover and recycle nanophotocatalysts since the fine dispersed nanoparticles are easily suspended in waters. Furthermore, a large amount of photocatalysts will lead to color contamination. Thus, it is necessary to prepare photocatalysts with easy separation for the reusable application. To take advantage of high photocatalysis activity and reusability, magnetic photocatalysts with separation function were utilized. In this report, the solar light photocatalytic degradation of ibuprofen (IBP) as a model of pharmaceutical pollutants in water media was investigated. Two types of magnetic nanophotocatalysts (Magnetic Fe3O4/Bi2WO6 and POM-γ-Fe2O3/SrCO3 nanohybrids) were used for photocatalytic degradation of IBP. In the case of Fe3O4/Bi2WO6 nanohybrid, high photocatalytic activity was obtained under sunlight condition with the addition of hydrogen peroxide improving the efficiency of IBP degradation. Further, the removal of IBP in the dark condition could be ignored (Fig.1 and 2). In the case of POM-γ-Fe2O3/SrCO3 nanohybrid in comparison with the γ-Fe2O3/ SrCO3, the degradation of IBP after 2-h exposure to the solar light irradiation was significantly higher for POM-γ-Fe2O3/ SrCO3 nanohybrids and the degradation of IBP was enhanced by the addition of H2O2 to the air saturated solution. The photocatalytic activity and magnetization properties of this magnetic photocatalyst nanohybrid provide a promising solution for the degradation of water pollutants and photocatalyst recovery.

Keywords:

Magnetic properties , Photocatalysis , Degradation , Solar light , Pharmaceutical pollutants