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چکیده
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The development of eco-friendly nanomaterials has attracted growing interest as sustainable alternatives to conventional chemical synthesis. In this work, cerium oxide nanoparticles (CeO₂n) were synthesized via a green co-precipitation route employing Laurus nobilis leaf extract as a dual reducing and stabilizing agent. The choice of L. nobilis is motivated by its rich content of bioactive phytochemicals, particularly polyphenols and flavonoids, which are expected to influence both nanoparticle stabilization and functional activity. The as-synthesized nanoparticles were systematically characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), ultraviolet–visible (UV–Vis) spectroscopy, and field- emission scanning electron microscopy (FESEM). XRD confirmed the formation of crystalline CeO₂n with a cubic fluorite phase, while FESEM images revealed quasi-spherical and nanorod morphologies. UV–Vis spectra showed a blue-shifted absorption edge near 300 nm, indicative of quantum-size effects, with calculated band gaps inversely related to particle size. The photocatalytic activity was assessed through the degradation of methyl orange under UV irradiation, achieving degradation efficiencies of 96.5%, 47.5%, and 77.3% for samples synthesized with 5, 10, and 15 mL of extract, respectively. The nanoparticles also demonstrated significant antioxidant potential, highlighting the synergistic contribution of phytochemicals in enhancing biological activity. From a chemical engineering standpoint, this study introduces a process-oriented approach by systematically investigating the effect of Laurus nobilis extract concentration on the structural, optical, and photocatalytic properties of CeO₂ nanoparticles. The results demonstrate a clear structure– property–performance relationship, offering valuable insight for the optimization and scale-up of green nanoparticle synthesis.
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