Phosphotungstic acid immobilized onto ZnO coated zerovalent iron (Fe@ZnO/PW) core/shell magnetic nanocomposite for enhanced photocatalytic bacterial inactivation under visible light

Abstract

Abstract In this work, phosphotungstic acid (PW)-based magnetic nanocomposite (Fe@ZnO/PW) was synthesized, characterized and used as a recyclable photocatalyst for bacterial inactivation of pathogenic E. Coli bacterium under LED lamps as a light source. Different characterization methods (X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), vibrating sample magnetometer (VSM), BET surface area and pore volume and UV-vis absorption spectra) were used to characterize the synthesized Fe@ZnO and Fe@ZnO/PW magnetic nanocomposites. The Fe@ZnO/PW nanocomposite retaining magnetic properties was easily separated using an external magnet. Fe@ZnO/PW could completely inactivate 107 cfu/ml of E. coli after 2 h of irradiation time. Considerably, Fe@ZnO/PW photocatalyst exhibited good stability and no reduction of its photocatalytic bacterial inactivation performance was observed even after six successive cycles.