| Summary: | 碩士 === 國立中興大學 === 環境工程學系所 === 107 === This research focused on the development of CuInS2 (CIS) photocatalyst, and investigated the effect of the solar-responsive photocatalyst CuInS2 on photodegradation of acid red 1 (AR1). The influence of the sulfur precursor, precursor/ethylene glycol ratio and synthesis temperature on the CuInS2 crystallization phase and the influence of the synthesis time on CuInS2 grain size were discussed in this study. Evaluate the effect of the crystal phase and grain size on the AR1 decolorization efficiency.
The results indicated that when thiourea and thioacetamide were used as the sulfur precursor, the crystal structure of CuInS2 were wurtzite and zinc blende, respectively. The oxidation potential of wurtzite CuInS2 was higher than zinc blende CuInS2, and the AR1 decolorization rate reached 34.1%. When the ratio of the precursor/ ethylene glycol was controlled at 5/50, the crystal structure of CuInS2 was zinc blende and wurtzite composite. The difference in redox potential between wurtzite and zinc blende CuInS2 could reduce the recombination rate of photoexcited electron-hole pairs, and the AR1 decolorization rate reached 86.1%. Moreover, the FESEM image indicated that the structure of the CuInS2 transferred from bulk to sheet structure, which reduced the recombination rate of photoexcited electron-hole pairs. Different CuInS2 synthesis temperatures affect the semiconductor type. When the temperature was controlled at 165 °C, the zinc blende and wurtzite composite CuInS2 ratio is 7:3, which effectively reduces the recombination rate of photoexcited electron-hole pairs and the AR1 decolorization rate under simulated sunlight is 93.1%.
The optimal AR1 decolorization rate is 99.3% when the synthesis temperature and synthesis time were controlled at 165 °C and 4 hr, respectively. In this system, the main photocatalytic oxide species were ∙OO- and h+, and the dye mineralization rate reached 54.4%.
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