Cds Nano-materials Synthesis And Properties

Over time, the nanotechnology is going into our lives. "Nano fever" throughout the world, it will bring new industrial revolution. Nano-CdS is very important inorganic materials. It has very wide range of applications such as biological testing, photosensitive resistors, field electroluminescent devices, photocatalysis, photovoltaic cells, infrared laser window regulator and so on. CdS nanoparticles as fluorescent markers have many advantages, for example, narrow line fluorescence, higher luminous efficiency, single excitation line, adjust light color, combined more tages, good light stability. But some factors will eliminate the fluorescence intensity in the biological monitoring, so the luminescence mechanism should be studied further. Nano-CdS as photocatalyst it has stable performance, nontoxic side effects, no secondary pollution, safety,ect. So CdS nanoparticles have widely used in the photocatalytic and found a suitable method to prepare nano-CdS with high catalytic activity is content of this thesis.This paper has the following components.Firstly, it summarizes the nano-technology, nanomaterials and nano-CdS, then introduces its preparation, properties and applications.Secondly, CdS nanoparticles have been prepared by microemulsion process, respectively, with different surfactant, such as sodium lauryl sulfate, cetyltrimethylammonium bromide, polyethylene glycol 6000. It has been characterized by SEM,XRD,FT-IR techniques, respectively. The nanoparticles are dispersed and higher purity. It has been studied the fluorescence properties and the photocatalytic activity. The results show that surfactant with cetyltrimethylammonium bromide is the best photocatalytic effect to methylene blue, congo red, methyl orange, malachite green, rhodamine B.Thirdly, it has been prepared by solvothermal method, which in the change of solvent to different nano-CdS sample. It has been characterized by SEM,XRD,FT-IR and HRTEM techniques, which is spherical particles, cubic crystal structure with high crystallinity, small size, high purity. The results show that CdS nanoparticles have good fluorescence properties and can be used as fluorescent probe to detect amino acids. At the same time, it has good photocatalytic activity.Fourthly, by changing the complexing agent are prepared CdS nanoparticles using hydrothermal method.The choice of complexing agent has influence on the product morphology, size and the nature. The results show that the same sample has different fluorescence properties on different amino acids, different samples has different fluorescence properties on the same amino acid. So does the photocatalytic activity. Fifthly, with sodium hexametaphosphate as the stabilizer by sol-gel synthesis with cadmium chloride and sodium sulfide nano CdS, and of their function modification. Studied the functional properties of nano CdS fluorescence of L-tryptophan were quantified.It discussed the influence of pH,amount of buffer solution and amount of nano CdS and so on.The result show that optimum conditions are pH=8, V=2.5 mL of potassium hydrogen phosphate citric acid buffer solution, amount of nano CdS 2.5 mL, water bath at 25℃for 30 min.At last, it gave a brief summary of this thesis and the outlook of the nanotechnology, fluorescence properties of CdS and photocatalytic activity future development.