| Summary: | 碩士 === 國立屏東科技大學 === 機械工程系所 === 97 === Recently, mesostructured materials with high surface areas and large pore sizes have attracted much attention because of their potential applications. In this study, mesoporous SnO2 was prepared by sol-gel process and the synthesis was accomplished by using triblock copolymer as the template, and SnCl4‧5H2O as the inorganic precursor. The effects of triblock copolymer additives, NH4OH additives, water and calcining temperatures on the structure of mesoporous SnO2 were investigated by TGA, X-ray, SEM, FTIR, TEM and BET analyses.
Using triblock copolymer as the template, mesoporous SnO2 with the cassiterite structure were obtained at 300~500°C. Mesoporous SnO2 exhibits a high specific surface area of 188 m2/g, and an average pore size of 40.77 Å for 300℃ calcination and using 1.5 g triblock copolymer. The mesostructure of SnO2 can be controlled by the addition of triblock copolymer. When the addition of triblock copolymer increased from 0.1 to 1.5 g, the specific surface areas increased from 121.49 to 188 m2/g after being calcined at 300℃.
The NH4OH and water content in the reaction system are believed to determine the microstructure formation. The mesoporous SnO2 was shown to have a specific surface area of 122.31 m2/g and the average pore diameter was 27.14 Å after it was calcined at 400 °C when the ethanol solvent was replaced with 25% NH4OH using 1.0 g triblock copolymer. The result also showed that mesoporous SnO2 prepared with 25 % replacement of water and calcined at 300°C exhibited a specific surface area of 207.99 m2/g and an average pore size of 89.97 Å.
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