Green and Chemically Prepared Zinc Sulfide Nanoparticles: A Comparative Study

Abstract

Biosynthesis of zinc sulfide (ZnS) nanoparticles (NPs) using plant extracts is an alternative method to traditional chemical route. In this study, ZnS-NPs was synthesized via two different routes: (i) bio-based method  using leaf extract of Plectranthus barbatus as a capping agent and (ii) using the chemical co-precipitation route as a capping–free method. The effect of synthesis routes on the structural, morphological, and optical properties of the prepared NPs was analyzed. The obtained ZnS-NPs was characterized using UV-Visible, FTIR, XRD, and SEM. According to XRD analysis, the average crystallite size were found to be 2.259 and 3.080 nm for chemically and bio-synthesized ZnS, respectively; while SEM revealed aggregated NPs to be counted. Additionally, the optical energy bandgap were 3.82 and 3.73 eV of the samples synthesized via chemical and green methods, respectively. The obtained results indicates that ZnS-NPs prepared via the capping–free chemical route is is more favored, in term of its morphological and optical properties, compared to the sample prepared by green method.