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

In this study, the sulfidization of CdO was investigated by using solid-gas reactions under a sulfidizing gas mixture that contained a gas mixture of carbonyl sulfide, COS, carbon disulfide, CS2 and sulfur Si. The greenockite form of cadmium sulfide, CdS, was synthesized for the first time via a reaction performed under a sulfidizing gas mixture. The reactions were performed at temperatures between 750 and 950 degrees 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 angstrom; c = 6.772 angstrom; space group, P6(3) (JCPDS 6-314). When the sulfidizing reaction was carried out below 700 degrees C, some unreacted CdO was encountered among the products. In the case of the reactions carried out at temperatures between 850 and 950 degrees C, even though there were some differences in the XRD peak intensities, the US with the greenockite form continued to be observed. Sublimation of US was observed for the sulfidizing reactions performed at 1000 degrees C or higher temperatures. Thus, the conditions for the synthesis reaction of CdS with the greenockite structure by the sulfidizing process were optimized with respect to the temperature and period of time as 750 degrees C and 3 hr, respectively.