Photocatalytic Properties of MnZnFe ₂ O ₄ Nanoparticles

Zinc ferrite (ZnFe2O4) is attracting increasing interest due to its advantageous optical properties and remarkable chemical and thermal stability. With its bandgap energy in the visible range, this ferrite is a promising material for the photodegradation of organic pollutants in wastewater, provided that its electronic structure is modified to reduce the rapid recombination of photogenerated electron–hole pair. In this study, an attempt to substitute manganese for zinc in the synthesis of zinc ferrite nanoparticles was successfully carried out using the sonochemistry method. Structural and morphological characterizations confirm the formation of nanoparticles, and optical properties reveal a significant decrease in the bandgap energy, from 2.03 to 1.41 eV with increasing manganese concentration. This ability to tune the bandgap energy allows for optimizing the material composition for a specific type of pollutant. Photocatalytic tests under visible light, focused on the degradation of the rhodamine B dye, demonstrate that the modified ferrite performs better than the initial material, where hydroxyl radicals play a key role in the dye degradation process. This enhanced photocatalytic efficiency is due to a better alignment of the energy bands of the ferrite material with respect to the standard hydrogen electrode, resulting in excellent photocatalytic activity combined with exceptional recyclability and high chemical stability. This control over doping allows for the tailoring of nanoparticles for large-scale wastewater treatment applications under solar visible light.