高螢光碳點之水熱合成與鑑定

本研究使用簡單之水熱法、加熱迴流法與微波方法製備高量子產率之螢光碳點，使用一些摻有羧酸基以及胺基基團的有機化合物做為起始物。反應所用之溶劑為超純水，使製程更為環保。在所有樣品中，使用水熱法製備之碳點的螢光量子產率比加熱迴流法和微波法高。其中以水熱法合成經過透析而獲得之最終產物達到最高螢光量子產率（35.23%）。該碳點之水溶液在可見光下為淡黃色，在紫外光照射下則發出藍色螢光。此外，以雷射粒徑分析儀測得該碳點在溶液中之平均粒徑為6.9 nm。實驗所收集之螢光碳點，皆利用螢光光譜儀測量其光激發光的性質、紫外線-可見光光譜儀測量其最大吸收波長、穿透式電子顯微鏡觀察其結構、X光繞射儀分析其晶相以及傅立葉紅外線光譜儀鑑定其化學官能基。最後，所有樣品在室溫下儲存三個月後，發現仍保持螢光強度。

The study used simple hydrothermal, reflux heating and microwave methods to prepare fluorescent carbon dots of high quantum yield (QY), and used some organic compounds incorporating carboxylic acid and amino groups as the precursors. The solvent used in reactions was ultrapure water which makes the process more environmentally protecting. The fluorescence QY of the carbon dots prepared by the hydrothermal method were higher than those by the reflux heating and microwave method. Among them, the highest QY (35.23%) was achieved for the final products obtained from hydrothermal method and through dialysis. The aqueous solution of the carbon dots was light yellow when observed under the visible light and emitted blue fluorescence if irradiated by the ultraviolet light. In addition, the mean particle size of the carbon dots in solution is 6.9 nm measured by the laser particle size analyzer. All the carbon dots collected in experiments were characterized by the fluorescence spectrometer for properties of photoluminescence, UV-Vis spectrometer for absorbance, transmission electron microscope for structure, X-ray diffractometer for crystal phases, and FTIR for chemical functional groups. Finally, all the samples kept their fluorescence intensity after storage at room temperature for three months.