Synthesis of Water-Dispersed Thioglycolic Acid-Capped ZnSe Quantum Dots in Aqueous Media

摘要

Water-dispersible ZnSe quantum dots (ZnSe QDs) were prepared in aqueous media and characterized by ultraviolet-visible absorption, fluorescence emission spectroscopy, X-ray powder diffraction, transmission electron microscopy, energydispersive spectroscopy, and inductively coupled plasma atomic emission spectroscopy. The influences of various experimental variables on the photoluminescence properties of ZnSe QDs were investigated. The results showed that the average diameter of these nanocrystals was 4 nm with narrow size distribution. The optimized conditions were as follows: pH value of 9.5, Zn/NaHSe molar ratio of 10:1, Zn/TGA molar ratio of 1:3, heating time of 1 h, and irradiation time of 19 h. Under optimized conditions, the photoluminescence quantum yield of ZnSe QDs in aqueous solution reached 20%.