| Summary: | 碩士 === 國立高雄第一科技大學 === 環境與安全衛生工程研究所 === 100 === The study applied TiO2/ITO composite thin-film probes to oxidize two typical antibacterial chemicals, sulfadiazine and sulfadimethoxine, by both photocatalytic (PC) and photoelectrocatalytic (PEC) processes under illumination of both near-UV (?軯 365 nm) and LED blue light (?軯 470 nm). The reaction probes were prepared by magnetically sputtering processes through which thin layers of TiO2 were deposited on as received ITO thin films. Majorly two different types of TiO2 thin films were prepared in the study. One is pure TiO2 thin film majorly in anatase crystalline, and the other one is anatase TiO2 co-doped with carbon atoms. Several experimental parameters including solution pH levels, applied bias, and different light sources were tested in the study. The degradation rates of these target pollutants were measured for evaluating the effects of these experimental parameters on their degradation rates. The results were also applied to discuss their degradation reaction mechanisms.
Some important results were achieved in the study. In comparison of pure PC reaction rates for the investigated pollutants, their degradation rates were enhanced up to 42 folds in the PEC reactions, and the rates typically increased with applied bias. It was also observed that both pollutants had higher degradation rates in lower pH environments. While applied bias was equal to 1.0 V, solution pH at 3.0 and irradiated with near-UV and LED blue light, the highest reaction rate constant for sulfadiazine and sulfadimethoxine were 1.156 hr-1 and 1.152 hr-1, respectively. The major contribution to the reaction by the additional bias is to retard the recombination rate of photo-generated electrons and holes, resulting in forming more hydroxyl radicals or altering adsorption rates of reactants onto the probes.
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