Preparation Of ZnS And Zn_xCd + (1 - X) S Composites And Their Photocatalytic Properties

As one of significantly important semiconductors, Zn S can exist in two forms: cubic zinc blend structure and hexagonal wurtzite structure, whose band gap energy is 3.5–3.7 e V and 3.7–3.8 e V, respectively. Recently, Zn S has been researched extensively and it is applied importantly in many fields, such as optical device, electronics, photocatalysis, etc. Bhargava and his co-workers reported that the performance of Mn2+ doped Zn S was more superior for the first time in 1994. The result drew a lot of scientists’ attention to doped Zn S.The thesis could be divided into two parts mainly. In the first section, ZnS microspheres were synthesized and characterized. In the second section, ZnxCd(1-x)S composites were prepared and characterized. The specific content are as follows: 1. The preparation of Zn S microspheresZn S particles were synthesized by hydrothermal method in chapter 2, using Zn(CH3COO)2 and thioacetamide. A series of cubic Zn S could be obtained by changing the hydrothermal temperature, reactant mole ratio and reaction time. They were characterized through XRD, SEM, infrared spectroscopy and fluorescence spectroscopy. The photocatalytic properties were measured. In chapter 3, Zn S particles were synthesized by hydrothermal combined with precipitation method, with the usage of Zn(NO3)2 and thioacetamide. By altering the reaction temperature, reactant mole ratio and reaction time, a series of cubic Zn S could be get. They were characterized via many ways. The photocatalytic properties were measured.2. The synthesis of ZnxCd(1-x)S composites In chapter 4, ZnxCd(1-x)S composites were prepared by solvothermal process, using the specimen synthesized in chapter 3, as the matrix and ethanol as solvent. The ratio, reaction temperature and time were discussed. The microstructure, morphology and spectra of composite materials were analyzed. The photocatalytic performance was evaluated. In addition, Cd S microspheres were prepared, with Zn2+ doped in them. Altering reaction parameters, another kind of ZnxCd(1-x)S were obtained. The photocatalytic performance of the two kinds composites were compared.