Photocatalytic degradation of diclofenac sodium under UV light by a biosynthesized magnetic spinel nickel ferrite (NiFeO) nanoparticles using rosemary leaf extract.

In this study, we report the first successful biosynthesis of magnetic nickel ferrite nanoparticles NiFeO NPs via a sono-chemical method, employing ultrasonic assistance and using rosemary leaves extract as a multifunctional capping, reducing, and stabilizing agent. This approach was undertaken with the aim of developing a catalyst for the photodegradation of the nonsteroidal anti-inflammatory drug diclofenac sodium (DS), which not only represents an environmentally benign alternative to conventional chemical methods but also results in NiFeO NPs with enhanced structural, optical, and magnetic properties. Characterization by XRD and FESEM-EDX analysis indicated the formation of NiFeO NPs with quasi-spherical morphology. TEM/HR-TEM analysis revealed its spinel phase structure, with particle sizes ranging from 4 to 20 nm. FT-IR was utilized to elucidate molecular vibrations, while VSM revealed the superparamagnetic behavior of these NPs; this property enables their efficient recovery after the photocatalytic process. The photocatalytic degradation of DS by NiFeO NPs with a band gap energy of 2.7-3.32 eV was examined under ultraviolet light (UV-A) irradiation. Various operating parameters, including solution pH, DS concentration, and NiFeO catalyst dose, were studied. The degradation kinetics were monitored using a UV-Visible spectrophotometer. The biosynthesized NiFeO NPs demonstrated a high degradation efficiency of 95% for DS in acidic pH conditions within only 140 min. The NiFeO NPs exhibited excellent recyclability and maintained structural and photocatalytic stability over three consecutive photodegradation cycles.