The dissertation aims to prepare iron oxide (Fe₂O₃) and zinc sulfide (ZnS) nanoparticles via a green synthesis approach using mint leaf extract as an eco-friendly reducing and stabilizing agent. It also aims to fabricate core–shell nanostructures, including Fe₂O₃@Ag/AgCl, ZnS@Ag₂S, ZnS@Fe₂O₃, and ZnS@Fe₂O₃/Ag, investigate the effect of different silver nitrate (AgNO₃) concentrations on their composition and properties, evaluate their photocatalytic efficiency in the degradation of methylene blue dye under ultraviolet (UV) irradiation, and assess their cytotoxic effects on normal Rat Embryo Fibroblast (REF) cells and human breast cancer (MDA-MB-231) cells using the MTT assay.

The dissertation also included the characterization of the synthesized nanoparticles using X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), and ultraviolet–visible (UV–Vis) spectroscopy. Their structural, morphological, and optical properties were investigated. The results confirmed the successful green synthesis of the nanoparticles and the formation of core–shell nanostructures, with improved properties following silver incorporation. These improvements contributed to enhanced photocatalytic performance and increased cytotoxic activity against human breast cancer (MDA-MB-231) cells while maintaining good biocompatibility toward normal Rat Embryo Fibroblast (REF) cells.

• Conducting in vivo studies to evaluate the safety and therapeutic efficacy of the prepared nanostructures.
• Investigating the molecular mechanisms underlying the effects of the nanostructures on cancer cells.
• Evaluating the efficiency of the prepared nanostructures in the removal of other organic pollutants and in industrial wastewater treatment .

Excellent with Honors.