Synthesis and Catalytic Properties of Nanosized Zinc and Nickel Ferrites

Nanosized NiFe₂O₄ and ZnFe₂O₄ were synthesized by the citrate combustion method. The nanopowders were characterized by elemental analysis and powder X-ray diffraction; size, dispersion, and morphological features were determined. It was established that the nanopowders of the synthesized ferrite spinels (average particle size 38 ± 3 nm for NiFe₂O₄ and 49 ± 3 nm for ZnFe₂O₄) are effective catalysts for the oxidation reaction of methylene blue dye (degradation efficiency 92% for nickel ferrite and 95% for zinc ferrite). The observed dependence of the catalytic activity of nanosized ferrites on the type of illumination is more pronounced for nickel ferrite (a 2.5-fold increase in the reaction rate constant and a 31% increase in the degradation efficiency).