Microwave-assisted hydrothermal preparation of metal sulfide powder and photochemistry for hydrogen evolution
碩士 === 國立中央大學 === 化學工程與材料工程學系 === 102 === Energy crisis and environmental protection are big challenges of this century. Hydrogen is the most promising replacement for fossil fuels. Therefore, the development of visible-light-driven photocatalysts for water splitting is critical. The purpose of this...
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| Format: | Others |
| Language: | zh-TW |
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2014
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| Online Access: | http://ndltd.ncl.edu.tw/handle/89346091428040318582 |
| Summary: | 碩士 === 國立中央大學 === 化學工程與材料工程學系 === 102 === Energy crisis and environmental protection are big challenges of this century. Hydrogen is the most promising replacement for fossil fuels. Therefore, the development of visible-light-driven photocatalysts for water splitting is critical. The purpose of this study is to effectively use photocatalysts to change solar energy into hydrogen energy.
We used ZIS (ZnmIn2S3+m) as visible-light-driven photocatalyst. Its water splitting reaction rate increased with the temperature. The absorption of the nanoshells in the coreshell nanoparticles can be adjusted systematically from visible light to IR range making the solar energy into heat and resulted in local thermal effect which can effectively enhance hydrogen evolution to 74%. Because the nanoshell was formed by silver and gold nanoparticles, it had the surface plasmon resonance. Using nanoshells absorbing at 700 nm can transfer enengy to photocatalysts and separated the combination of electrons and holes in photocatalysts making the enhancement of hydrogen evolution to 1.62 times.
We also changed the thickness of SiO2 on the nanoshells to observe the interaction between nanoshells and coreshells which might influence the enhancement of hydrogen evolution. When there was no SiO2, electron would transfer between nanoshells and photocatalysts. Thicker thickness of SiO2 might hinder the translation of energy from nanoshells decreasing the enhancement of hydrogen evolution.
Making photocatalysts directly into coreshell structures might cause thicker shell or uncovered nanoshells. So we try to mdify the surface of ZIS or mdify the surface of nanoshells and formed coreshell, making uniform distribution of ZIS on nanoshells.
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