Determination of the size of copper sulfide nanoparticles synthesized by chemical precipitation using the Scherrer equation

Abstract

This study reports the synthesis and structural characterization of copper sulfide nanoparticles (CuS NPs) prepared via the chemical precipitation method. The synthesis was carried out using aqueous solutions of copper (II) sulfate pentahydrate (CuSO4·5H2O) and sodium sulfide decahydrate (Na2S·10H2O) under controlled temperature and constant stirring conditions. Structural characterization was performed by X-ray diffraction (XRD). The diffraction patterns showed good agreement with the reference data reported in the International Centre for Diffraction Data (ICDD) database (PDF 00-06-0464), confirming the formation of the covellite phase with a hexagonal crystal structure. The average crystallite size was estimated from the broadening of the diffraction peaks using the Scherrer equation. The calculated crystallite sizes ranged from 6.62 nm to 14.01 nm, indicating that the synthesized material exhibits nanometric crystalline domains. It should be noted that the Scherrer equation provides an estimation of the coherent diffraction domain size (crystallite size), which does not necessarily correspond to the actual particle size in cases where nanoparticles are polycrystalline or form aggregates. The observed size variation is attributed to the intrinsic anisotropy associated with the hexagonal crystal structure of the covellite phase.