Study On The Syntheses, Characterizations And Application Of The Eu³⁺ Doped CdS Nanoparticles

In this dissertation, the work is mainly focused on the synthesis and opticalproperties of chalcogenides nanoparticles fabricated in aqueous and oil phase. Thenanoparticles are characterized by the measurement of TEM, HRTEM, XRD, FTIR,UV, and PL. We also studied the effect of the experimental conditions on opticalproperties of nanoparticles and the growth mechanism.1. The CdS: Eu nanoparticles have been prepared by autoclave in ethyleneglycol. The PL of the CdS: Eu nanoparticles are affected by reaction time, reactiontemperature, storage time, storage conditions and different compositions. Meanwhile,the PL intensity, PL wavelength of CdS: Eu nanoparticles can be tuned under differentpH values. The PL intensity of the CdS: Eu nanoparticles decreased, when CdS: Eunanoparticles were coated by TGA. Then, the PL of CdS: Eu nanoparticles isimproved by adding the charge composition ions2. The PL of CdS: Eu nanoparticals is improved by coating a shell of ZnS. Inaddition, The PL of the CdS: Eu nanoparticles are affected by the reaction conditions.And the biocompatibility of the CdS: Eu and CdS: Eu/ZnS nanoparticles weremeasured by hemolytic test, which indicated that they are biocompatible. It isimportant for nanoparticles as biomarkers in biological detection and diagnosis.3. The CdS: Eu nanoparticles have been prepared in methylglycol. The PL ofthe CdS: Eu nanoparticles are affected by molar ratio of Cd/S, reaction time andreaction temperature. The PL of CdS: Eu nanoparticles is improved by adding thedifferent charge composition ions, such as Li⁺、Na⁺、K⁺. And the PL of CdS: Eunanoparticles are strongest by adding Li⁺, and the PL of CdS: Eu nanoparticles areweakest by adding K⁺.4. The CdS: Eu nanoparticles have been prepared by aqueous precipitation. ThePL of the CdS: Eu nanoparticles are affected by reaction time, pH values. Then, Themethod for the determination of Hg²⁺ion using CdS: Eu nanoparticles as thefluorescent probes were developed. The response of nanoparticles fluorescence probeswas linearly proportional to the concentration of Hg²⁺ions ranging from5×10-8to1×10-3mol·L-1. The reaction mechanism of the fluorescent quenching was nvestigated. Furthermore, the method was successfully applied to the determine Hg²⁺ions in different real samples.