Příprava nanokompozitů ZnS a CdS na montmorillonitu a jejich využití pro fotoredukci a fotooxidaci vybraných látek

Abstract

ZnS and CdS nanoparticles were prepared in the presence of a stabilizing compound, commonly the cationic surfactant cetyltrimethyammonium. The resulting nanosuspensions were deposited on the clay mineral montmorillonite leading to the origin of stable powdered nanocomposite. The properties of the nanoparticles and their nanocomposites were examined by several instrumental analytical methods. The size of the nanoparticles was 3.5 nm (ZnS) and 4.8 nm (CdS), respectively. The nanoparticles were aggregated by means of the surfactant and equally distributed over the montmorillonite surface. The efficiency of the prepared nanocomposites for the photoreduction of dissolved carbon dioxide was found to be 3- to 8-fold higher in comparison with the standard commercial photocatalyst TiO2 (P25 Evonik). The phodegradation of phenol in solution was also very efficient. The decomposition by just the UV light and the adsorption of phenol on the montmorillonite contributed to the overall phenol removal. The nanocomposite of cadmium sulphide appeared to be more resistant against the photocorrosion and release of the nanoparticles to the solution during the photoreactions. However, in case of possible utilization of both nanocomposites it is necessary to pay attention to the environmental protection because of potential contamination by heavy metals.