Co-substituted Mg–Zn spinel nanocrystalline ferrites: Synthesis, characterization and evaluation of catalytic degradation efficiency for colored and colorless compounds

Abstract

In this investigation, cobalt substituted Magnesium–Zinc ferrites were successfully synthesized by using the co-precipitation technique. The prepared spinel ferrites were characterized by using Scanning electron microscopy (SEM), Ultraviolet–Visible analysis, X-ray powder diffractometer (XRD) and Fourier-transform infrared spectroscopy (FTIR). Confirmation of formation of a single-phase spinel structure was assessed by the XRD and FTIR. Crystallite size, evaluated from X-ray analysis, of MZF, MZF1, MZF2, MZF3 is 9.72 nm, 7.21 nm, 8.49 nm and 8.30 nm respectively. Cluster formation and agglomeration of powdered samples of Co substituted Mg–Zn ferrites were represented through the SEM images. The optical bandgap range was calculated from the Ultraviolet–Visible spectrum. The photocatalytic activity was assessed through the photodegradation of coloured and colourless pollutants under sunlight. This paper focuses on the photocatalytic degradation of harmful compounds like benzimidazole and methylene blue. The photocatalytic activity of Mg–Zn ferrites as a photocatalyst was enhanced by the substitution of cobalt in it. Especially, MZF3 with the highest cobalt content gave the maximum photodegradation of methylene blue. Hence, we conclude that Mg0.5Zn0.5CoxFe2O4 works as a potential catalyst in wastewater treatment.