Superparamagnetic Zinc Ferrite Nanoparticles as Visible-Light Active Photocatalyst for Efficient Degradation of Selected Textile Dye in Water

Abstract

Photocatalysis is a promising technology for the degradation of recalcitrant organic pollutants in water. In this study, superparamagnetic zinc ferrite nanoparticles (ZnFe2O4) were synthesized and characterized using scanning electron microscopy, X-ray diffraction, energy dispersive X-ray and Fourier transform infrared spectroscopy. The synthesized nanoparticles (NPs) of ZnFe2O4 were observed to have a photosensitive nature and showed characteristic visible-light-induced activation that was used for the photocatalytic degradation of a textile dye, Remazol brilliant violet 5R (RBV-5R). The effect of different operational parameters such as pH, H2O2, catalyst dosage, concentration of RBV-5R and the reusability of ZnFe2O4 as well as scavengers were investigated under visible irradiation. The almost complete degradation (99.9%) of RBV-5R was observed at pH 10, 0.1 g of ZnFe2O4 and 6 mM of H2O2 in 30 min. The photocatalytic degradation of RBV-5R followed pseudo-first-order kinetics. The mineralization was calculated from total organic carbon (TOC) that was represented by 82% TOC removal in 30 min. The results revealed that visible-light-induced ZnFe2O4 photocatalysis may be a promising technology for the elimination of toxic organic dyes, such as RBV-5R, from water resources.

Keywords

• visible light-assisted photocatalysis
• zinc ferrite (ZnFe₂O₄) nanoparticles
• Remazol brilliant violet 5R
• water treatment
• advanced oxidation processes