Facile green synthesis of zinc oxide nanoparticles by Eucalyptus globulus and their photocatalytic and antioxidant activity

Eucalyptus globulus leaf extract mediated synthesis of spherical zinc oxide nanoparticles (ZnO NPs) was carried out under ambient conditions. UV–Visible studies of the synthesized nanoparticles revealed the characteristic peak at 361 nm indicating the formation of ZnO nanoparticles. Powder X-ray Diffractometric (XRD) study showed the strong, intense and narrow-width diffraction peaks indicating the formation of crystalline nanoparticles with most stable hexagonal phase. Field emission-scanning electron microscopy (FE-SEM) and high resolution-transmission electron microscopic (HR-TEM) results confirmed the formation of spherical ZnO NPs with mean particle size of 11.6 nm which is in close agreement with XRD pattern. Further, energy dispersive X-ray diffraction analysis (EDAX) revealed the formation of highly pure ZnO NPs with the peaks of Zn and O atoms. ZnO NPs exhibited effective photocatalytic activity in degrading Methylene blue and Methyl orange with maximum degradation efficiency up to98.3% at 30 mg of catalyst doses. In addition, ZnO NPs exhibited high antioxidant activity against DPPH free radicals scavenger