Summary: | 碩士 === 國立臺北科技大學 === 化學工程所 === 94 === The sol-gel and aerogel methods were used to prepare TiO2 nanoparticles and their compositions and properties were modified with metal ions, such as silver, nickel, palladium and lithium ions. These nanocomposite materials act as photocatalysts for the degradation of TNT in aqueous solution. The sizes and crystal phases of the TiO2 composites were examined by SEM, PXRD methods, respectively. Under low concentration of TNT (32 ppm), the sol gel-Ag/TiO2 catalyst exhibited that the rate of photocatalytic degradation of TNT for 30 minute irradiation was 92.5%. Whereas, the degradation rate of TNT by sol gel-Ag/TiO2 for 60 minute irradiation was 78.8% at high concentration of TNT (103 ppm). Prolonging the irradiating time to 90 minutes, the cracking ratio of TNT increased to 91.5%.
Glass cloth- and glass fiber-immobilized catalysts were prepared and their photocatalytic degradation efficiency of TNT in aqueous solution was investigated. Under low concentration of TNT (32 ppm), the Ag-TiO2/glass-cloth sample exhibited an efficiency of 66.1% for 80 minute irradiation. However, aero-sol gel-Ag/TiO2/glass-fiber immobilized catalyst showed a degradation rate of TNT of 70.3% for 60 minutes irradiation at high concentration of TNT (112 ppm). By following three-step irradiation (20 minute irradiation for each step), the aero-sol gel-Ag/TiO2/glass-fiber immobilized catalyst exhibited a degradation ratio of 75.0% at high concentration (117 ppm) of TNT.
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