In this Thesis, the aim is to synthesize and identify calcium-zinc ferrite magnetic nanoparticles using olive tree leaf extract and surface modification and functionalization, as well as investigate some of their applications. In the first part of the research, CaZnFe2O4@OLE green magnetic nanoparticles were synthesized through the reaction of polyphenols present in olive tree leaf extract and iron, calcium, and zinc metal salts. Then, these green magnetic nanoparticles were coated with copper acetate salt. Various analyses, such as FT-IR, XRD, TGA, FE-SEM, ICP, VSM, and EDX-map, were used to confirm and identify the structure of CaZnFe2O4@OLE-Cu green magnetic nanoparticles. To investigate the application of synthetic magnetic nanoparticles, it was used as a catalyst in multi-component reactions, so by using these green magnetic nanoparticles, chromene derivatives (Scheme 1) and derivatives of bis coumarin (Scheme 2) were produced with a maximum efficiency of 95% and 97%, respectively. Also, these magnetic nanoparticles were well used in the catalytic reduction process of some nitrophenol compounds. In this process, the reduction was done well, and the rate constant values for 4-nitrophenol and 3-nitrophenol were reported as 0/0406 s-1 and 0/0103 s-1, respectively. On the other hand, the antibacterial properties of these magnetic nanoparticles were also investigated. The results showed that the synthesized green magnetic nanoparticles have good antibacterial properties. In another part of the work, we could functionalize the surface of CZFO@SiO2-Pr-Azo-SA magnetic nanoparticles in several synthesis steps. The structure of synthesized magnetic nanoparticles was identified and confirmed using FT-IR, TGA, XRD, FE-SEM, VSM, Zeta potential, and EDX-map analyses. After the synthesis and identification of these magnetic nanoparticles, it was used as a nano absorber of Rhodamine B (RhB) dye and lead metal ions (ΙΙ) from an aqueous solution. Two widely used models, Langmuir and Freundlich, were used to investigate the adsorption isotherm, and the obtained data showed that the adsorption process for rhodamine B dye and lead ions follows the Langmuir isotherm with a correlation coefficient of 0/9784, 0/9074, respectively. The maximum absorption capacity for rhodamine dye is equal to 13/59 mg / g and for lead ions is 322/58 mg /g of nano absorbent. In addition, the results showed that the reaction kinetics follows the pseudo-second-order adsorption kinetics model. The adsorption process of rhodamine B dye and lead ions by synthesized magnetic nanoparticles was exothermic. Also, thermodynamic parameters showed that the absorption process for both pollutants have a spontaneous nature.
