Green Synthesis of Zinc Oxide (ZnO) Nanoparticles Using Madhuca longifolia Flowers for Enhanced Photodegradation and Antibacterial Applications

The present study involves green synthesis of ZnO nanoparticles (NPs) using aqueous Madhuca Longifolia flower extract from hydrothermal synthesis. The ZnO NPs were characterized by X-ray diffraction (XRD), UV–visible studies, Transmission electron microscopy (TEM), FT-IR, SEM, and EDAX. The NPs were evaluated for photodegradative and antimicrobial activities. UV–visible absorption of ZnO NPs showed an absorption band at 356 nm, which can be assigned to an effective formation of ZnO NPs having appreciable activity in the visible range, confirmed by the Tauc plot showing a 3.21 eV band gap. TEM image confirms the formation of nanoparticles, and the average crystallite sizes were found to be 17-20 nm. Eosin Blue (EB) dye was effectively degraded under sunlight in the minimum quantity of ZnO NPs. Excellent bactericidal activity was shown by the NPs on Gram-positive (Bacillus cereus ATCC13061, Staphylococcus saprophyticus KCTC3345) and Gram-negative (Escherichia coli KCTC1682, Salmonella typhimurium KCCM11862) bacteria. Synthesis of multifunctional ZnO NPs using naturally occurring M. longifolia plant flower has been an excellent, cost-effective, and environmentally friendly alternative to chemical methods.