Příprava core-shell nanočástic CdS a ZnS a jejich fotokatalytické vlastnosti

Abstract

This master thesis deals with the preparation of semiconductor core-shell CdS-ZnS nanoparticles by using precipitation reactions at room temperature. The prepared core-shell nanoparticles were characterized by TEM and stability of their aqueous dispersions with cetyltrimethylammonium bromide was characterized by measuring the zeta potential. Energy band gap for single particles was determined from the measured UV-VIS spectras. Photocatalytic efficiency of core-shell nanoparticles has been studied in the degradation of methylene blue in aqueous solution, as a source of irradiation was used Hg lamp with an emission maximum of 365 nm. The residual concentration of methylene blue was determined from the UV-VIS absorption spectra. From the data it is evident that with increasing number of ZnS shells around the nucleus of CdS the photocatalytic efficiency decreases. Accelrys Materials Studio software was used to determine the theoretically required amount of ZnS to create a specific number of shells.