Zinc ferrite ZnxFe3–xO4 nanocomposites as efficient photocatalysts: a study of synthesis, properties and catalytic activity

Zinc ferrite nanocomposites ZnxFe3-xO4 (x=0, 0.5, 0.7, 0.8, 0.9, and 1) were successfully synthesized using the sol-gel co-precipitation technique. The physicochemical properties of the resulting nanocomposites were investigated using X-ray diffraction (XRD), Rietveld refinement technique (GSASII), scanning electron microscopy (SEM), Fourier transforms infrared (FTIR) spectrometry, UV/vis spectroscopy, and a vibrating sample magnetometer (VSM). The predominant phase in all of the samples was found to be ZnFe2O4 spinel, with other phases such as Fe2O3 and Fe3O4 also present. The crystallite size ranged from 6.87 to 10.88 nm, and the resulting spinel phase powder had grain sizes between 100 and 220 nm. The lattice constants and coercivity of the samples increased with increasing Zn concentration, while saturation magnetization decreased. The photocatalytic activity of the nanocomposites for the photo-degradation of methylene blue (MB) aqueous solution was investigated, and the ZnFe2O4 nanocomposites showed the highest MB degradation rate and efficiency (92%) within 60 minutes of UV and visible light irradiation. These results demonstrate the potential of ZnFe2O4 nanocomposites synthesized via the sol-gel co-precipitation technique for photocatalytic applications.