In this study, ZnO nanoparticles were successfully synthesized via a green co-precipitation method using orange peel extract as a natural complexing and stabilizing agent. XRD analysis confirmed a hexagonal wurtzite structure with an average crystallite size of 46 nm, which was significantly smaller than the 64 nm obtained for the control sample prepared without the extract, demonstrating the critical role of phytochemicals in restricting crystal growth. FE-SEM revealed spherical nanoparticles below 100 nm, and EDX confirmed zinc and oxygen as the dominant elements. FT-IR analysis showed a characteristic Zn–O vibrational band at 450–550 cm⁻¹ after calcination at 500 °C, confirming the removal of organic residues. UV-Vis absorption exhibited a strong band at 375 nm, with a DRS-derived band gap of 3.29 eV. Photoluminescence spectroscopy displayed a near-band-edge emission peak at 393 nm attributed to excitonic recombination, confirming high crystallinity and low defect density. Collectively, these results demonstrate that orange peel extract enables the green synthesis of high-quality, crystalline ZnO nanoparticles with favorable structural and optical properties suitable for photocatalytic and antimicrobial applications.
Hossein Yarahmadi (Sun,) studied this question.