| Summary: | 碩士 === 國立雲林科技大學 === 環境與安全衛生工程系 === 103 === In this study, bismuth oxide powders were prepared via a sol gel method using bismuth nitrate as the precursor at 450oC calcination temperature. Then, titanium dioxide and bismuth oxide with different molar ratio of Bi and Ti were coated on plate glass as a Bi2O3/TiO2 hybrid photocatalyst. All of samples were characterized with crystalline structure, morphology structure, elemental bonding, and energy gap variation. The effects of UV and simulated sunlight under various temperature to photodegrade gaseous 1,2-dichloroethane by the hybrid photocatalyst were investigated. In results of XRD, SEM and XPS analysis indicated that properties of hybrid Bi2O3/TiO2 photocatalyst were stable and did not produce impurity crystallization phases. In addition, the result of UV-Visible spectra analysis showed that the hybrid Bi2O3/TiO2 photocatalyst reduced the energy gap and was conducive to use of visible light wavelengths. Comparison with Bi2O3 and 1 mole% hybrid Bi2O3/TiO2 (1BT) photocatalyst in degrading gaseous 1,2-DCE with reacting 180 minutes, the efficiencies of degradation were 35% increasing to 99.6% under UV light and were 29% increasing to 82% under simulated sunlight, respectively. The result showed that the hybrid Bi2O3/TiO2 photocatalyst enhanced the effect of degradation significantly. In effects of temperature, the optimal temperature was 35oC which the removal efficiency was 83% under simulated sunlight. These results demonstrated that raising the temperature over 35oC would make catalyst surface of deactivation. In FTIR analysis, the photocatalytic intermedium and final product after degradation found C2H6, HCOOH, CO2 and H2O but did not find more toxic substance than 1,2-DCE. In durability, 62% after five repeated experiments exited. Finally, all the results indicated the hybrid Bi2O3/TiO2 catalysts not only separated photogenerated hole and electron pairs for improving photocatalytic activities, but had durability.
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