Synthesis of CdS nano-spheres by a simple and fast sonochemical method at room temperature

Nano-spheres of hexagonal CdS were prepared by a sonochemical method using CdCl2 and Na2S2O3 as precursors, with different molar ratios of cadmium and sulfur in starting solutions, in ethylene glycol and cetyltrimethylammonium bromide (CTAB) as a surfactant. The XRD patterns for all samples presented the set of peaks characteristic of CdS in hexagonal phase. The crystallite size decreases as the sulfur content increased in the starting solution as a consequence of the quick release of sulfide ions trapped in the micelles formed by the CTAB surfactant, which controls the CdS nanoparticles growth. The diffuse reflectance spectroscopy (DRS) results have shown that it is possible to tune the emission of visible light of the CdS semiconductor changing only the starting Cd:S ratios in this synthesis procedure. •Hexagonal CdS was prepared as homogeneous nano-spheres by a sonochemical method.•The crystallite size decreases as the sulfur content increased in the starting solution.•It was possible to tune the emission of visible light of the CdS changing Cd:S ratios in the synthesis procedure.