Pure and Yb3+-doped ZnS (YbxZn1−xS) nanoparticles were prepared in this research via hydrothermal route at 160 °C and 12 h. The obtained products were characterized by means of Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and X-ray powder diffraction (XRPD). XRPD analyses displayed that the particles were perfectly crystallized and assigned to the cubic structure of zinc sulfide. TEM and SEM images indicated that the sizes of particles were in the range of 10-80nm.The photocatalytic performance of Yb3+-doped ZnS nanoparticles was assessed in an aqueous solution by observing the decolorization of Tartrazine (Yellow 5) in the process of visible-light radiation. The degradation percent of Yb0.06Zn0.94S and bare ZnS was 92.15 and 22.10% after 100 min of treatment, respectively. 6% Yb3+-doped ZnS nanoparticles demonstrated the highest removal efficiency between various values of dopant agent. It was noticed that the existence of inorganic ions like C2O42−, I−and other radical scavengers like benzoquinone and butanol decreased the decolorization efficiency.
