γ-Radiolysis preparation of nanometer-sized cadmium sulphide quantum dots stabilized in nanozeolite X and ZSM-5

Abstract

The radiolytic preparation of CdS nanoparticles stabilized in colloidal zeolites is presented. Nanosized zeolites with different structural frameworks, i.e. FAU and MFI, are used as host materials for the stabilization of different amounts of Cd²⁺. The colloidal zeolites are stabilized in ethanol and then subjected to γ-irradiation in the presence of mercaptoethanol to generate HS⁻ anions that diffuse and react with Cd²⁺ to form CdS. The growth of the CdS nanoparticles is supported by the results of UV-vis absorption and emission spectroscopy. The formation of CdS is mostly limited by the total irradiation dose, and the size of the CdS NPs can be controlled; thus, small isolated CdS oligomers to larger interconnected clusters with tunable optical properties can be formed.