Recyclable and Photocatalytic Properties of ZnFe2O4/ZnO for Wastewater Treatment and Disinfection

In this work, the magnetic and photocatalytic ZnFe2O4/ZnO, at two different ratios (1 : 1 and 1 : 8), have been prepared via a simple one-step method. Characterization of the nanocomposite was performed using Dynamic Light Scattering (DLS), Fourier Transformed Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Brunauer-Emmett-Teller (BET) isotherm. The photocatalytic activity was evaluated by monitoring the photodegradation of methylene blue and the photo-assisted bleaching of p-nitrosodimethylaniline, under UV365nm irradiation. The photocatalytic performance is related to the amount of ZnO on the composite. Therefore, using ZnFe2O4/ZnO at 1 : 8 ratio (0.1 mg mL(-1)), efficiency of 80 % was achieved after 120 min. The material can be recovered magnetically and reused for at least three consecutive cycles without losing their activity. Water disinfection performance was also determined by measuring E. coli inactivation. Remarkably, ZnFe2O4/ZnO at 1 : 8 (0.1 mg mL(-1)) proved to be more effective for bacterial inactivation than ZnO alone, with an inactivation performance of 90 % after 15 min. Interestingly, these composites can be used as highly efficient photocatalysts for wastewater treatment and water disinfection, and are magnetically separable and reusable.