Biosynthesis of zinc oxide nanoparticles and their catalytic and disinfection evaluation

Abstract

The present work reports the green engineered synthesis of Zinc Oxide Nanoparticles (ZnO NPs) via fresh leaves of Phyllanthus emblica. The standard crystallite dimension (D) obtained for the synthesized NPs were 19.56 nm as determined by Scherrer formula. The XRD peaks corresponding to pure hexagonal wurtzite crystalline structure confirms the formation of ZnO. The spherical shape of ZnO NPs has been confirmed by TEM images. The band at 876 cm−1 corresponds to the vibrations of elongation and deformation of the Zn-O vibration as confirmed by FT–IR spectra. UV-Visible reflectance reveals optical energy gap of 3.35 eV for the synthesized sample. The TGA analysis revealed that the samples underwent a continuous weight loss up to 600 °C. Prepared ZnO NPs have displayed antibacterial activity against two bacterial strains viz, Staphylococcus aureus and Proteus vulgaris. The synthesized NPs show a higher antibacterial activity for gram positive Staphylococcus aureus (12 mm) than gram negative Proteus vulgaris (5 mm) as estimated by the standard pharmaceutical formulation. Further, photocatalytic activity (PCA) of prepared NPs were also analyzed for Malachite Green (MG) under UV light irradiation. Nearly 91.8% of decolorization of dye occurred in 60 min of time intervals suggesting that the ZnO NPs prepared by biosynthesis route will be much valuable for dye bacterial decontamination and decolorization.