Green synthesis and characterization of zinc oxide nanoparticles using Eucalyptus globulus Labill. leaf extract and zinc nitrate hexahydrate salt

Abstract

This study consists of a reliable process for synthesizing ZnO NPs by green method. Here, Eucalyptus globulus Labill. leaf extract is utilized as an efficient chelating and capping agent for synthesizing ZnO NPs from zinc nitrate hexahydrate salt. The plant ingredients, structure, morphology, thermal behavior, chemical composition and optical properties of ZnO nanoparticles were investigated using several characterization techniques, namely XRD, FE-SEM, EDX, BET, Zeta potential, DLS, differential scanning calorimetry (DSC) analysis, FT-IR analysis and UV–Vis spectroscopy. The UV–Vis and FTIR analysis of Eucalyptus globulus leaf extract verified that this extract is a promising candidate for biosynthesizing ZnO NPs. The XRD spectrum, DLS and the SEM images confirmed the crystallinity and the spherical-shape of the ZnO NPs with an average size between 27 and 35 nm. The band-gap of the ZnO were measured to be around 2.67 eV. Zeta potential and BET analysis showed that, the biosynthesized ZnO NPs possess good stability and the their specific surface area is 23.481 m2/g. DSC analysis exhibits two endothermic peaks related to the water evaporation absorbed by the NPs and modification of zinc complex to zinc hydroxide, with a single exothermic peak related to the crystallization of ZnO NPs and degradation of organic materials.