碩士 / 國立成功大學 / 化學工程學系 / 104 / This study details the synthesis of high-activity g-C3N4 catalysts for H2 generation from a triethanolamine aqueous solution under visible light. We anneal a mixture of urea and NH4Cl to obtain g-C3N4 nanosheets, which are subsequently solvated with ethanol molecules and annealed to form aromatic carbon-doped g-C3N4. The results of analyses conducted using X-ray photoelectron, Fourier-transform infrared, and 13carbon-13 nuclear magnetic resonance spectroscopies demonstrated that annealing the ethanol molecules leads to the grafting of aromatic heterocycles on the g-C3N4 nanosheets. The results of photoluminescence and electron paramagnetic resonance measurements reveal that the grafted aromatic heterocycles extend the π-conjugation system in g-C3N4 to reduce the band gap and facilitate the separation of photogenerated charges. The grafted aromatic heterocycles also preserve the crystallinity of g-C3N4 during high-temperature annealing, which facilitates the suppression of the recombination of photogenerated charges at defect sites. The developed aromatic carbon-doped g-C3N4 effectively catalyzes H2 generation from water decomposition, achieving apparent quantum yields of 14% and 2.2% under 420- and 550-nm monochromatic irradiation, respectively, whereas urea-derived g-C3N4 reached only 3.4% and 0.1%. The proposed strategy of extending the π-conjugation system is promising for promoting the activity of carbon-nitride photocatalysts.
| Identifer | oai:union.ndltd.org:TW/104NCKU5063077 |
| Date | January 2016 |
| Creators | Po-KaiChuang, 莊博凱 |
| Contributors | Hsisheng Teng, 鄧熙聖 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 109 |
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