Photocatalytic Activity of ZnFe₂O₄ Nanoparticles for the Degradation of Fast Green FCF and Orange II Dyes

Introduction: Synthetic dyes are extensively used in various industries. However, their persistence, toxicity, and resistance to biodegradation make them significant environmental pollutants, particularly in wastewater. Traditional treatment methods often fall short in completely removing such contaminants. In recent years, photocatalysis using semiconductor materials has emerged as a promising approach to dye degradation under mild conditions. Among various metal oxide photocatalysts, zinc ferrite (ZnFe₂O₄) has gained attention due to its narrow band gap, good stability, low cost, and activation under visible light.

Methods: ZnFe₂O₄ nanoparticles (NPs) were synthesized using a co-precipitation process and tested for photocatalytic effectiveness in degrading synthetic dyes under visible light. UV-Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX) were used to confirm the structural, optical, and morphological features of the produced ZnFe₂O₄ sample. The photocatalytic activity was tested with Fast Green FCF and Orange II Sodium Salt, two common azo dyes.

Results: The spectrophotometric monitoring of dye degradation revealed that the produced material had significant photocatalytic efficacy. Under visible light irradiation for 90 minutes, the ZnFe₂O₄ NPs achieved 54% degradation of Fast Green FCF and 73% degradation of Orange II Sodium Salt.

Conclusion: This study emphasizes the benefits of utilizing ZnFe₂O₄ NPs as a visible-light-activated, cost-effective, and environmentally friendly photocatalyst. These findings add to the growing corpus of research aimed at establishing sustainable wastewater treatment options.