Green Synthesis and Structural Characterisation of Zinc Oxide Nanoparticles and Chitosan-Zinc Oxide Nanocomposite Using Azadirachta Indica aqueous Leaf Extract

Abstract

Nanotechnology involves the use of nanoparticles to solve problems in various scientific fields including medicine and agriculture. This study was aimed to synthesise Zinc Oxide Nanoparticles (ZnO NPs) and Chitosan-Zinc Oxide Nanocomposite (CS-ZnO NC) using aqueous leaf extract of Azadirachta indica. Phytochemical analysis was carried out on the fresh leaf extract using standard methods. The synthesized Zinc Oxide nanoparticles and chitosan-zinc oxide nanoparticle composite were characterized for optical properties, crystallite size, functional groups, and morphological structure using UV-visible spectrophotometry, X-Ray Diffraction (XRD), and Scanning Electron Microscopy (SEM) respectively. The phytochemical screening revealed the presence of alkaloids, flavonoids, tannins, saponins, and terpenoids, which serve as reducing and stabilising agent for the synthesis of Zinc Oxide nanoparticles and Chitosan-Zinc Oxide Nanocomposite. Using Debye-Scherrer’s equation, the average crystallite sizes of ZnO NPs and CS-ZnO NC were 28.3 nm and 20.3 nm respectively. The SEM studies revealed ZnO NPs and CS-ZNO NC to have hexagonal to almost spherical morphological structures. The findings of this study suggest that ZnO NPs and CS-ZnO NC can be synthesised via green method using Azadirachta indica aqueous leaf extract for use in removal of glyphosate from contaminated water.