Synthesis and Characterization of ZnSb₂S₄ in an Aqueous Sb₂S₃–ZnSO₄ System: Thermogravimetric, X-Ray Diffraction, and Electron Microscopy Analyses

Zinc antimony sulfide (ZnSb₂S₄) is an antimony-based chalcogenide of interest because of its potential functional applications. In this study, a low-temperature aqueous route was investigated for the synthesis of ZnSb₂S₄ through the reaction of antimony(III) sulfide (Sb₂S₃) with zinc sulfate (ZnSO₄), using Sb₂S₃ derived from Daridagh antimony ore as the starting material. The effects of the reactant ratio, solution pH, and reaction conditions on product formation were examined. Chemical analysis indicated that the elemental composition of the synthesized product was consistent with the proposed ZnSb₂S₄ formula. The quantitative assessment suggested that approximately 75% of the antimony was retained in the solid phase, whereas the remaining 25% was present in the solution. Product formation was strongly influenced by solution pH, with more favorable results obtained under mildly acidic to near-neutral conditions. Strongly acidic conditions inhibited the formation of the target product. The obtained product was characterized using thermogravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). TGA results indicated that the material remained relatively stable up to approximately 300 °C, followed by a substantial mass loss at higher temperatures. XRD measurements provided information on the structural characteristics of the synthesized product, while SEM observations revealed its morphology and microstructure. Overall, the results suggest that the aqueous Sb₂S₃–ZnSO₄ system provides a relatively simple, low-temperature route for preparing zinc–antimony sulfide materials from ore-derived precursors.