A new route for the synthesis of cadmium sulfide by reacting of cadmium oxide with sulfidizing gas mixture

Abstract

In this study, the sulfidization of CdO was investigated by using solid-gas reactionsunder sulfidizing gas mixture which contains the gas mixture of carbonyl sulfide, COS, carbondisulfide, CS2 and sulfur, S 2. The greenockite form of cadmium sulfide, CdS, was synthesized as first time via the reaction performed under sulfidizing gas mixture. The reactions were performed at temperatures between 750 and 950°C. The X-ray diffraction patterns (XRD) of the solid crystalline products revealed the stable greenockite form of CdS with a hexagonal structure having the unit cell parameters a = 4.135, c = 6.772 Å, space group, P63mc (JCPDS 6-314). When the sulfidizing reaction carried out below 700°C, some unreacted CdO was encountered among products. In the case of reactions carried out temperatures between 850 and 950°C, even though there are some differences in the XRD peak intensities, the CdS with greenockite form was continued to observe. Sublimation of CdS was observed for the sulfidizing reactions performed at 1000°C or higher temperatures. Thus, the conditions for the synthesis reaction of CdS with greenockite structure by sulfidizing process were optimized with respect to temperature and period as 750°C and 3 hr, respectively.