Comparative study of (NiFe2O4) photocatalysts for oxytetracycline degradation: Effect of synthesis method on performance stability

Oxytetracycline (OTC) is an antibiotic characterized by its persistence, bioaccumulation, and low biodegradability, posing a significant risk to human health. In this study, the degradation of OTC under visible light was investigated considering the structural, morphological and photocatalytic performance of NiFe 2 O 4 nanoparticles under different synthesis methods (mechanochemical, hydrothermal, sol–gel and solid state). The materials were characterized using XRD, XPS, SEM, BET, FT-IR spectra, UV–Vis, PL, and Raman spectroscopy to evaluate their crystallinity, particle size, elemental composition and oxidation states, bandgap, and surface properties. NiFe 2 O 4 synthesized by the mechanochemical method exhibited the highest photocatalytic efficiency, achieving 84.57% OTC degradation, attributed to its lower band gap (1.745 eV) and enhanced surface reactivity. In comparison, NiFe 2 O 4 produced by the sol–gel method also demonstrated high degradation efficiency, while the samples obtained via the hydrothermal and solid-state methods showed lower photocatalytic activity, attributed to their larger bandgaps and more significant particle agglomeration. Photocatalytic stability was evaluated over multiple reaction cycles, with the mechanochemically synthesized sample showing the highest stability. This study highlights the importance of synthesis methods in optimizing the photocatalytic properties of NiFe 2 O 4 , establishing it as a promising material for removing pharmaceutical contaminants from water. • Among the NiFe 2 O 4 samples analyzed, showed the highest photocatalytic efficiency. • The low bandgap favored better visible light absorption, resulting in a degradation rate of 84.57%. • The morphology and particle size were strongly influenced by the synthesis. • NFO-1 show the highest stability in photocatalytic cycles, optimizes photocatalytic properties. • NFO-1 show structural stability, making it suitable for environmental photocatalysis.