石墨烯 (Graphene) 由於其具由良好的機械應力、高比表面積、電子傳輸效率以及生物相容性，因此自發現以來一直是廣為研究的題材；而當我們將石墨烯以化學或物理方式將其使尺寸縮小時，會由於量子侷限校應以及邊際效應而使得其性質改變，當其能階被調控到適當範圍時就有可能會釋放出螢光，視為石墨烯量子點 (Graphene Quantum dots) 。而石墨烯量子點除了承襲上述石墨烯的各種優點之外，由於反應時所添加的試劑不同，更有可能在其表面上修飾不同官能基，進而利用其具有螢光特性對於不同目標分析物進行偵測及其他應用。但是在以化學合成方法上，通常需要強酸及高能量的輔助才得以將石墨烯碎裂成量子點，因此，在本篇的研究中皆以較溫和的雙氧水作裂解，並加入不同的反應試劑以參雜不同元素，並將所合成出的石墨烯量子點應用於溫度感測、細胞照影及氧氣還原反應上。
在第一篇研究中，我們以氨水及雙氧水作為反應試劑，可以在反應不同時間後得到分別得到黃色、綠色及藍色的石墨烯量子點。並利用其熱淬息的螢光消光機制對於溫度作為感測，可以得到偵測響應範圍在10℃到100℃之間；接著利用其具有良好的生物相容性的特點，作為細胞顯影試劑並成功的應用在Hela cell上。
而在第二篇研究，延續了以雙氧水作為自由基裂解氧化石墨烯的反應，我們希望能以加入不同的反應試劑後能得到放光波長更接近紅光的石墨烯量子點，以此為前提下，我們找到了含硫的分子：硫脲 (thiourea) ，在雙氧水及硫脲的反應下，可以在短反應時間 (10分鐘) 下得到放光在630 nm的石墨烯量子點。接著亦以此石墨烯量子點作為溫度感測探針，同樣的可以得到良好的響應範圍在10℃到100℃之間。此外，由於此石墨烯量子點參雜了氮及硫這兩種元素，破壞了原本的石墨烯表面，使其產生缺陷進而提高對催化的效率，且由於氮及硫的未鍵結電子對會使得鄰近的碳產生相對正電的情況，亦有利於氧氣的吸附，因此我們將這個石墨烯量子點應用於催化氧氣還原的反應上，與市面上常見的催化材料Pt/C相比，此合成的石墨烯量子點具有不受甲醇干擾而使得效能降低的優點，同時重複測試500次的情況下，其循環伏安圖並沒有產生太大變化，因此可以做為一個非貴金屬的催化性材料，可以大幅降低燃料電池的成本。

Since graphene was discovered in 2004, it has been seen as a rising star in many field. Owing to its numerous advantages, such as high conductivity, large surface area and excellent mechanical strength, it drew extensive attentions and made many scientist devoted in its development. Furthermore, when its size comes to nanoscale, the nano-sized graphene, namely, graphene quantum dot (GQD) shows a fluorescent property. This phenomena makes GQD much more fascinating because of these benefits mentioned above.
At first study, we used ammonia and hydrogen peroxide to produced hydroxyl radical, which made it tearing graphene oxide into graphene quantum dots. After characterization of GQD, we speculated a proposed mechanism. By using the thermal quenching of its fluorescence, GQD has been proved as a good fluorescent thermometer at the range between 10℃ and 100℃. Besides, the good biocompatibility of nano-carbon materials makes GQD a promising probe of cellular imagine. Herein, the color of cellular imagines of Hela cell can be regulated as the experiment design due to the broad excitation and emission band of GQD.
The second study will focus on the enhancement of oxygen reduction reaction (ORR) of GQD. It’s commonly accepted that the ORR efficiency is associated with the heteroatom that doped inside carbon materials. With the similar reaction at first study, we used hydrogen peroxide as the source of hydroxyl radical. Besides, as the second reagent, thiourea has been chosen to doping sulfur and nitrogen into GQD. The S,N doped GQD showed a great methanol-tolerance and durability against commercial catalyst, Pt/C. With the financial benefit of carbon material, it would be hopefully decrease the cost of fuel cells.

論文審定書 i
論文公開授權書 ii
摘要 iii
圖目錄 vii
表目錄 viii
縮寫表 ix
第一章、 緒論 1
一、 石墨烯量子點的基本特性 1
二、 石墨烯量子點的合成方式 3
三、 石墨烯量子點的應用 4
第二章、 氨水輔助自由基生成氮參雜石墨烯量子點作為溫度探針及細胞照影 5
一、 前言 5
二、 實驗部分 7
2-1. 實驗藥品 7
2-2. 儀器裝置 9
2-3. 溶液配置 11
2-4. 合成步驟 12
2-5. 細胞養殖與細胞吞噬 13
三、 結果與討論 14
3-1. 合成結果鑑定與反應機制探討 14
3-2. 溫度感測 29
3-3. 細胞顯影 36
3-4. 氧氣還原反應 38
四、 結論 39
第三章、 以硫脲分子增進氮參雜效益並改善石墨烯量子點催化氧氣還原反應 40
一、 前言 40
二、 實驗部分 43
2-1. 實驗藥品 43
2-2. 儀器裝置 45
2-3. 溶液配置 48
三、 結果與討論 51
3-1. 合成結果鑑定與反應機制探討 51
3-2. 溫度感測 61
3-4. 氧氣還原反應 (Oxygen Reduction Reaction，ORR) 64
四、 結論 68
第四章、 參考文獻 69

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