Tuning the Properties of ZnS1-x Nanoparticles by Controlling Reaction Conditions

Abstract

In this work, a modified synthesis method was deployed to obtain nanocrystalline zinc sulfide from zinc acetate. By utilizing the hydrothermal and sol gel method, the influence of; reaction time, solvent and temperature control was used to tune the properties of zinc sulfide. Our results showed that ZnS obtained by sol gel in water + hydrothermal (ZnS (A)) typified formation of increased sulfur vacancies while an increase in reaction time resulted in decreased sulfur vacancies. The introduction of chemical defects in sol gel in methanol + KOH obtained ZnS resulted in lower grain size. We observed that crystallinity improved with increased reaction time and the introduction of KOH and methanol as solvent could shorten the reaction time required for improved crystalline property. Our result showed that reaction time influenced the dislocation density of the material to a greater extent than type of solvent used. The crystallite size estimated by Scherer formula was between the range 2.50–4.91 nm while the band gap energy of the ZnS samples were calculated in the range 3.8 eV- 4.6 eV. Utilizing this novel synthesis method can stimulate new directions in synthesizing ZnS crystals with options of choosing appropriate method for specific applications depending on properties to be traded off.