Chemical Liquid Synthesis Of Nano-selenium

Selenium (Se) is not only an important semiconductor material but also an essential element in life. The Se nanoparticles have aroused great interest due to its special properties on material and biological activity in life. In synthesizing Se nanoparticles, chemical technology with low temperature liquid phase, which possesses some virtues such as low reaction temperature, low cost as well as high control ability for the morphology of products, has received much attention. In this thesis, some chemical approaches with low temperature liquid phase have been employed to prepare Se nanoparticles and varied Se nanoparticles were obtained.1. Reverse microemulsion method Se nanoparticles were prepared by using sodium dodecane (SDS) as surfactant, n-butanol as aid-surfactant and cyclohesane as solvent. The reaction was based the reduction of Na2SeSO3 to elemental Se in acid environment. The uniform spherical Se nanoparticles and Se nanowires were obtained. The factors affecting the morphologies of the products and the formation mechanism of Se nanoparticles were discussed.2. Organic-medium ultrasonic method Se nanoparticles were prepared under ultrasound irradiation condition in organic solvent. One-dimension selenium nonostructures were obtained under ultrasound irradiation condition in ethanol medium. Spherical OP-Se micronscale compound was prepared under ultrasound irradiation condition in OP medium.3. Aqueous method using surfactants as soft templates Using polyvinylpyrrolidone (PVP) as a template, Se nanoparticles with various morphologies, such as nanospheres, nanorods and nanowires, were prepared in HCl-diffusing method and precipitation method. Se nanospheres and nanowires were also obtained using other surfactants as templates, such as sodiumdodecylsulfate, polyethylene glycol tert-octylpheneylether, hexadecyl pyridinium chloride, polyacrylamide and L-phenyl alanine. The function of templates to the formation of nanoparticles and the synthesis mechanism were discussed.4. Ag crystal nucleus method Se nanoparticles were prepared by using Ag crystal nucleus as inducing reagent in the presence of PVP. Se nanorods containing nanotubes were obtained. The function of Ag crystal nucleus was studied.