Effects of processing parameters on green synthesised ZnO nanoparticles using stem extract of Swertia chirayita

Abstract

This study focuses on the effective synthesis of ZnO nanoparticles from the stem extract of Swertia chirayita via the use of zinc acetate as precursor. Three different synthesis methods namely Sonication, Wet-chemical and Hydrothermal methods were used in the development of ZnO nanoparticles, due to its simple and easily scalable attribute. A comparative assessment was subjected over the prepared ZnO nanoparticles to evaluate the influence over the nanoparticles physico-chemical property and also to determine the most effective processing method to green synthesise ZnO nanoparticles. The ZnO nanoparticles synthesised demonstrates retainment of spherical crystalline structure, even though the processing parameters of the ZnO nanoparticles were varied during its synthesis. ZnO nanoparticles synthesised using hydrothermal process exhibits smaller particle size (17 nm), better photocatalytic activity (88.67%) and antibacterial activity against Escherichia coli (26 mm) and Staphylococcus aureus (28 mm) compared to the other ZnO nanoparticles. These results could be strongly attributed to the smaller particle size due to the controlled pressure and temperature employed during the production of ZnO using hydrothermal process. The observed result revealed the calibrable nature of the ZnO nanoparticles property in virtue of its processing parameters and also its high affectivity in biomedical application.