Comparative Green Synthesis of ZnO Nanoparticles Using Morus alba and Morus nigra: Influence of Phytochemicals on Nanoparticle Properties

This study evaluated the efficiency of the secondary metabolites of Morus alba and Morus nigra leaves in the ZnO NP green synthesis. Both species exhibited comparable levels of total phenols (0.742 and 0.756 mg g⁻¹) for M. alba and M. nigra. Higher flavonoids (0.260 mg g⁻¹) in M. nigra compared to Morus alba (0.113 mg g⁻¹) was observed, while tannins were equal (0.006 mg g⁻¹) in both. UV–Vis’s spectra showing peaks at 367.70 and 370.1 nm confirmed the ZnO NP formation using M. alba and M. nigra aqueous leaf extracts respectively. FTIR analysis confirmed Zn–O stretching vibrations near 428 cm⁻¹ and the presence of functional groups (O–H, C=O, and C–O). XRD patterns confirmed the hexagonal wurtzite structure, with peaks corresponding to the standard ZnO planes in both species. EDX showed high purity of Zn and O with 78.42 and 21.58% in M. alba and 78.20 and 21.80% in M. nigra. The nanoparticle was quasi-spherical, with mean sizes of 46.22 nm for M. alba and 56.01 nm for M. nigra. The findings show both species are effective for producing pure ZnO NPs, with M. nigra exhibiting stronger reducing capacity and M. alba generating more uniform nanoparticles. Both species proved to be effective and promising for sustainable plant-based ZnO nanoparticle synthesis.