GREEN SYNTHESIS OF ZNO NANOPARTICLES

Abstract

The extensive applicability and diverse characteristics of metallic oxide nanomaterials in the fields of sustainable remediation, biology, and electronics render them a promising material. Among the various metal oxides, zinc oxide (ZnO) nanoparticles are particularly noteworthy due to their high exciton binding energy (60 meV) and wide band gap (3.37 eV). Techniques such as metallurgical processes, sol-gel methods, mechanochemical approaches, and laser ablation have all been employed to synthesize ZnO nanoparticles. In comparison to more traditional techniques, green synthesis is considered more stable, less hazardous, and more cost-effective. Any part of the plant—including the stem, leaves, flowers, fruit, and roots—may be utilized as the phytochemical concentrate, which functions as a capping and reducing agent during the synthesis process. In addition to aqueous plant extract, a precursor such as zinc acetate dihydrate, zinc sulfate, or zinc nitrate is incorporated during the synthesis. Among the various reducing and capping agents found in the plant extract are phenolic acids, flavonoids, alkaloids, terpenoids, proteins, polysaccharides, saponins, and tannins. Furthermore, fungi, bacteria, algae, and plant extracts may all be employed in green synthesis. This study thoroughly examines the different plant extracts utilized in the production of ZnO nanoparticles. Additionally, this publication delivers an outline of current advancements in the synthesis of zinc oxide nanoparticles using fungi, bacteria, and algae.