Antibacterial Activity and Photocatalytic Performance of Zinc Oxide Nanoparticles from Morus alba L.

The plant-mediated synthesis of zinc oxide nanoparticles (ZnO NPs) using Morus alba L. leaf extract has been developed as a low-cost, environmentally benign, and simple approach. Characterization techniques such as UV-Visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were used to confirm biosynthesis, crystalline nature, morphology, dimensions, and elemental composition of the ZnO NPs. XRD confirmed the hexagonal wurtzite phase of ZnO with an average crystallite size of 30.54 nm. X-ray dispersive spectroscopy suggests that the composition of ZnO NPs is represented by the emission of 76% of the total energy by zinc and 13% by oxygen. The antibacterial activity of the biosynthesized ZnO NPs was evaluated, which indicates significant inhibition of bacterial strains, including Vibrio cholera and Escherichia coli (O157:H7), as compared to native ZnO. The maximum inhibition zones of ZnO NPs at a 50 mg/mL concentration were observed for V. cholerae and E. coli (O157:H7) at 24.3 ± 2.4 and 16.5 ± 2.7 mm, respectively. Moreover, the photocatalytic activity of the synthesized ZnO NPs was examined through the photodegradation of a methylene blue (MB) solution under solar light irradiation. The photodegradation efficiency of MB increased by 50% at ZnO NP concentrations of 30 ppm. This suggests that the synthesized ZnO NPs exhibited promising photocatalytic and biological properties in various applications.