Diclofenac sodium is an anti-inflammatory drug commonly used to cure pain in various treatments. The remarkable potential of this pain-killer leads to its excessive use and, therefore, a persistent water contaminant. Its presence in aqueous bodies is hazardous for both humans and the environment because it causes the growth of harmful drug-resistant bacteria in water. Herein, we present a comparative study of the ZnO and ZnFe₂O₄ as photocatalysts for the degradation of diclofenac sodium, along with their structural and morphological studies. A simple co-precipitation method was used for the synthesis of ZnO and ZnFe₂O₄ and characterized by various analytical techniques. For instance, the UV-Vis study revealed the absorption maxima of ZnO at 320 nm, which was shifted to a longer wavelength region at 365 nm for zinc ferrite. The optical band gaps obtained from the Tauc plot indicated that the incorporation of iron has led to a decreased band gap of zinc ferrite (2.89 eV) than pure ZnO (3.14 eV). The metal-oxygen linkages shown by FTIR indicated the formation of desired ZnO and ZnFe₂O₄, which was further confirmed by XRD. It elucidated the typical hexagonal structure for ZnO and spinel cubic structure for ZnFe₂O₄ with an average crystallite of 31 nm and 44 nm for ZnO and ZnFe₂O₄, respectively. The micrographs obtained by SEM showed rough spherical particles of ZnO, whereas for ZnFe₂O₄ flower-like clustered particles were observed. The photocatalytic investigation against diclofenac sodium revealed the higher degradation efficiency of ZnFe₂O₄ (61.4%) in only 120 min, whereas ZnO degraded only 48.9% of the drug. Moreover, zinc ferrite has shown good recyclability and was stable up to five runs of photodegradation with a small loss (3.9%) of photocatalytic activity. The comparison of two catalysts has suggested the promising role of zinc ferrite in wastewater remediation to eliminate hazardous pharmaceuticals.

	Year	Citations

References