Efficient and Sustainable Synthesis of Zinc Salt-Dependent Polycrystal Zinc Oxide Nanoparticles: Comprehensive Assessment of Physicochemical and Functional Properties

This research involved synthesizing zinc salt-dependent zinc oxide nanoparticles (ZS-ZnO-NPs) using different zinc salts (ZnCl2, ZnSO4·H2O, Zn(CH3COO)2·2H2O, and Zn(NO3)2·6H2O) and plant extracts of Phoenix dactylifera L. The synthesis efficiency was evaluated, and to carry out further investigations, zeta potential measurements, as well as SEM and TEM examinations, were performed to assess the morphology and size distribution of the nanoparticles. XRD and UV-Vis spectroscopy were also employed to confirm the crystalline nature and optical properties of the synthesized ZS-ZnO-NPs, respectively. FTIR analysis was also performed to identify chemical groups on the nanoparticle surface. Furthermore, the ZS-ZnO-NPs’ ability to scavenge free radicals (FRs·), and thus their antioxidant capacity, was assessed using the DPPH FR· assay. The results showed that the type of zinc salt used for the synthesis significantly influenced the yield, stability, optical properties, morphology, and size distribution of nanoparticles. The zinc salt-dependent yield exhibited a notable range, varying from 50.3% to 55.3%. The nanoparticle size ranged from 3.7 to 10.2 nm, with the zeta potential ranging from −28.6 to −46.7 mV and the gap energy (Eg) ranging from 3.28 to 3.39 eV. Moreover, the synthesized ZS-ZnO-NPs exhibited concentration and time-dependent inhibitory activity against DPPH FR·, showing potential as antioxidant agents in biomedicine and other industries.