本研究之長程目標為利用掃描探針顯微術檢驗氧化石墨烯的表面性質，因此本論文就氧化石墨烯的合成與鋪膜以及掃描探針的製備進行系統性的研究。氧化石墨烯雖然已被研究一段時間，但由於合成條件及石墨來源的差異對所製得之氧化石墨的結構都有顯著的影響，而目前對這些合成條件進行系統性探討的研究尚付之闕如，因此難以穩定控制所製得之氧化石墨烯的品質。本實驗整理了不同的製備條件與氧化石墨烯的顏色及性質差異，由於氧化程度影響了石墨烯共軛結構長短及其光學吸收的不同範圍，在低溫環境下，所製備的氧化石墨烯氧化程度差，光學吸收遍及可見光範圍，不僅顏色偏綠色且仍有明顯未氧化的石墨存在，在較高溫反應下，氧化程度較好且光學吸收藍移，顏色呈現亮黃色，但溫度過高（超過80 °C）會導致反應中的氧化劑分解而降低了氧化程度。本研究利用最優化的條件合成薄層（few layer）氧化石墨烯後，為了避免一般以旋轉塗布或滴落塗布的方式，所鋪陳之氧化石墨烯很容易產生皺摺及重疊而不利於後續鑑定之故，選擇利用改良朗謬-布洛傑特技術，將濃度0.015-0.02 mg/ml的氧化石墨烯懸浮液鋪陳於矽晶片上，調整副相pH為3-4，能得到型態較佳的薄膜，統計整體平均片徑落在20-30 µm。另外為了製備檢驗氧化石墨烯表面性質的掃描探針，採用成本低廉且簡單方便的熱裂解碳沈積的方式製備雙通道奈米碳電極，在兩種火焰強度下，皆以沉積時間10秒時有著較低的缺陷深度及較高的成功率，以STEM計算之探針孔徑大小為134.6 nm，電化學量測的穩態電流大小平均為132 pA和86 pA，雖找到較佳的沉積條件，但對於滴管尖端的隔板破損仍無法準確避免，需再對製備過程進行近一步的改良。

The long term goal of this research is to investigate the interface properties of graphene oxide (GO) with nanopipette-based scanning probe microscopy (SPM) techniques. First of all, we try to optimize the synthesis process to prepare few layered GO for advanced interfacial examination. Through systematic investigation, the correlation between reaction conditions and the resultant properties of GO has been demonstrated. The optical properties of produced GO is found to be significantly affected by the synthesis conditions, which determines the oxidation degree and thus the length of conjugated  bond system in GO. It was found that synthesized GO with high oxidation degree shows light-brown color due to absorption of short wavelength of visible light by the short conjugated  bonds. In contrast, GO products with dark-green color indicate low oxidation degree, which increases the difficulties in exfoliation process, resulting in GO flasks with a thicker layer. With the optimal synthesis process, we are able to prepare few layerd GO with thickness smaller than 5 nm. For advanced examination with SPM, GO flasks are deposited on silica substrate by a modified Langmuir-blodgett (LB) technique to obtained a flat film of isolated GO flasks with less wrinkles and overlaps. By adjusting the acidity of the subphase solution used in modified LB technique to be pH 3-4, the prepared LB film of GO shows better quality when 0.015-0.02 mg/ml of GO suspension was applied and the average size of deposited GO flasks is in the range of 20-30 µm. In the last part, a multifunctional nanopipette was fabricated as the scanning probe of SPM to facilitate the interfacial characterization of GO. By pyrolytic deposition of carbon into selected barrel of a two-channel nanopipette, we successfully prepared a SPM probe which is able to record faradic and ionic measurement simultaneously.

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