Comparative Studies of Biosynthesized Zinc Oxide Nanoparticles

Abstract

Zinc oxide nanoparticles are one of the known safe compounds, and their low toxicity makes them suitable for waste water remediation. An environment-friendly approach of synthesizing nanoparticles is the use of plant extracts which are rich sources of phytochemicals as reducing agents. In this research, aqueous extracts of four different plants' leaves were analyzed and found to contain anthocyanins, steroids, phenolics, saponins, flavonoids, and terpenoids. Optimization study prepared the precursors (zinc salt and plant extracts) in varying volume-ratios of 1:1, 1:2 and 2:1; a higher yield was observed for the ratio 1:1 having calculated percentage yields of 50.0 %, 64.1 %, 21.8 %, and 68.0 % for leaves of guava, tropical almond, lemon, and Mexican sunflower, respectively. The TEM characterization of these biosynthesised nanoparticles have sizes in the range 0.22 nm and 5.80 nm, while the EDS spectra presented these nanoparticles as highly pure having major elements of zinc and oxygen. The small sizes and very high purity of the biosynthesised nanoparticles make them fit for adsorption applications such as waste water remediation.