Synthesis Of CdS Nanomaterials Modified With Surfactants And Mechanism Development

Cadmium sulfide (CdS) is a novel functional material in great potential applications because of its special light and electric properties. It is a kind of typical Ⅱ-Ⅵ semiconductor materials whose bandgap is2.42eV at ambient temperature. Surfactants are very common agents in chemistry lab and they have been more and more often used to nano-synthesis. For their different physical and chemical characteristics, such as the existence of hydrophilic and hydrophobic groups and the formation of micelles in some high concentration, they enjoy exceptional advantages and will great benefit to prepare the uniform size nanoparticles. The main content of my paper is such as following:1. Synthesis of uniform and monodisperse CdS nanospheres modified with cationic surfactant CTABWe prepared uniform and monodisperse CdS nanospheres with the size of40nm via a simple hydrothermal method using CTAB as a capping agent. The electron microscopy and laser light scattering were carried out to demonstrate the monodispersity of CdS nanospheres. Surfaces of nanoparticles had been totally occupied by CTAB which was illustrated with infrared spectra and TG analysis. It was found that the nanospheres were not sensitive to concentration after changing the agents’concentration, which was benefit to mass production in future. At last we discussed the mechanism of the reaction in brief.2. Counterion Cd2+-assisted synthesis of the uniform CdS nanospheres capped with anionic surfactant SDSThe uniform CdS nanospheres have been successfully prepared in the presence of anionic surfactant SDS with an adequate concentration. The nanospheres were characterized by electron microscopy, X-ray dirraction, ultraviolet-visible and photoluminescence techniques. Infrared spectra, thermogravimetric analysis and zeta measurements were used to further study the formation of nanospheres. A possible mechanism was proposed to explain how anionic surfactant molecules SDS adsorbed the negatively charged surface. The applications of CdS nanospheres were investigated in adsorption and photocatalytic performance of methylene blue (MB).3. The novel nanosize ring-shaped CdS particles modified with CTABWe synthesized a kind of novel nanosize ring-shaped CdS particles in160℃high temperature via hydrothermal method using CTAB as a modifying agent. The reaction temperature, the concentration of reactants and different surfactants were deeply discussed in details. A possible mechanism was established to explain the formation of nanorings with TEM of different reaction time, which involved oriented aggregation and Ostwald ripening.