Preparation And Study Of TiO₂,SnO₂ And TiO₂-SnO₂ Nanometer Powders

In this dissertation, a novel chemical route was adopted under a mild or simple condition, based on the reviewing the research on the function, preparation and applications of nanomaterials for preparing nanometer TiO₂, SnO₂ powders and TiO₂-SnO₂ complex nanometer powders. First, nanometer TiO₂ powders were prepared by heating of alcohol-aqueous salt solution, stearic acid sol-gel, PEG method and azeotropic distillation. Then, SnO₂ nanometer powders were prepared by azeotropic distillation. And the last, TiO₂-SnO₂ complex nanometer powders were prepared by azeotropic distillation. The details are summarized as follows:1. Based on the previous researches, the author developed a novel chemical route to prepare nanometer TiO₂ powders. The nanometer TiO₂ powders were prepared by liquid-state method. Nanoparticles of TiO₂ powders were synthesized by heating of alcohol-aqueous salt solution, stearic acid sol-gel, PEG method and azeotropic distillation. The average particle size and tetragonal content of the prepared powders were analysed with X-ray diffraction instrument. The results showed that the nanoparticles of the average size of TiO₂ with 9nm-15nm could be obtained by heating of alcohol-aqueous salt solution, those in the average size of 10nm-25nm could be obtained by stearic acid sol-gel method, those in the average size of 12nm-18nm could be obtained by PEG method and those in the average size of 5nm-15nm could be obtained by azeotropic distillation. The samples calcinationed at 500℃ by PEG method and heated in alcohol-aqueous slat solution were all anatase. The sample prepared from the stearic acid sol-gel and calcinationed at 550℃ was in the form of both rutile and anatase. The sample prepared by azeotropic distillation and calcinationed at 450℃ was in the form of anatase. The nanometer TiO₂ powders looked like good dispersivity, few reunion, evenly distributed the size of particles and narrow range of the diameter.2. Nanometer S11O2 powders were prepared under the normal pressure and low temperature by azeotropic distillation. The tetragonal content, the average particle size and micro appearance, dispersive feature of the prepared powders were analysed with X-ray diffraction instrument and electronic transmitting winner. The results revealed that, perfect crystals, good dispersivity and 7nm-15nm diameter square phrase rutile type SnO2 powders were obtained under the condition of 450°C-700°C, baked for 2h, using liquid state chemical method of precipitation(the method of tri-co-distilled components) from SnCl4-5H2O? Ti(SO4)2 and aqueous ammonia as raw materials. The process is simple and suitable for mass production.3. Based on the previous work, nanometer TiO2-SnO2 complex powders were prepared under the normal pressure and low temperature by liquid state chemical method of precipitation. The average particle size and tetragonal content of the prepared powders were analysed with X-ray diffraction instrument. The results showed that, perfect crystals, good dispersivity and 10nm-20nm diameter TiO2-SnO2 complex powders were obtained under the condition of 450°C-700°C, baked for 2h, using liquid state chemical method of precipitation(the method of tri-co-distilled components) from SnCLj-SE^O, Ti(SC>4)2 and aqueous ammonia as raw materials. With the rising of heated treatment temperature, the brilliant type of TiO2 was changed to the rutile type from the anatase type, SnO2 entering into the crystal lattice of TiO2> forming crystallization intact complex powders.