臺灣博碩士論文加值系統

尖晶石結構的氧化鎳鈷(NiCo2O4)是近年來極力研究的電化學相關材料，其具有高孔隙度、高比表面積及良好的電化學特性；石墨烯量子點(Graphene quantum dots，GQDs)為奈米等級的石墨烯碎片，由於其量子點的發光特性及良好的電化學性質，是近期相關電化學研究中較為新穎的碳材。
本實驗分成兩部分，第一部分以水熱法來合成CuCo2O4與NiCo2O4，以應用於直接甲醇燃料電池之陽極觸媒材料，利用X光繞射分析儀(X-ray diffraction，XRD)作結晶分析，並使用場發射式掃描式電子顯微鏡(Field emission scanning electron microscope，FE-SEM)與場發射式穿透式電子顯微鏡(Field emission transmission electron microscope，FE-TEM)來觀察表面形貌及特性；在含有1 M氫氧化鉀與0.5 M甲醇的混合溶液中比較兩種陽極觸媒對於甲醇的電催化活性，其中NiCo2O4比CuCo2O4展現更優異的甲醇電催化活性與穩定性，並以此結果進行第二部分實驗。
第二部分以一步合成的水熱法來合成NiCo2O4/GQDs複合材料，以應用於直接甲醇燃料電池之陽極觸媒材料，利用X光繞射分析儀(X-ray diffraction，XRD)作結晶分析，並使用場發射式掃描式電子顯微鏡(Field emission scanning electron microscope，FE-SEM)與場發射式穿透式電子顯微鏡(Field emission transmission electron microscope，FE-TEM)來觀察表面形貌及特性；隨著GQDs含量的增加，熱重分析(thermogravimetric analysis，TGA)將被用來確認所合成觸媒之GQDs含量。NiCo2O4/GQDs複合材料在含有甲醇的鹼性溶液中，對甲醇的氧化展現優異的電觸媒活性，其中NCO/G2在含有1 M氫氧化鉀與0.5 M甲醇的混合溶液中，展現較低的起始電壓0.34 V及卓越的電流密度103.8 A/g，且具有良好的電化學穩定性，此實驗結果將對直接甲醇燃料電池之非鉑的陽極觸媒材料的發展有更進一步的幫助。

Recently, a novel material, the spinel structure of binary transition metal oxides NiCo2O4 have been applied on electrochemical researches as a result of their high porosity , high active area and excellent electrochemical performance. Graphene quantum dots (GQDs) are nanometer-sized fragments of graphene, usually applies on electrochemical researches because of the luminous characteristics of quantum dots and perfect electrochemical properties.
The study includes two parts, in part I, CuCo2O4 and NiCo2O4 were synthesized via hydrothermal method and applied to methanol oxidation. X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM) and field emission transmission electron microscope (FE-TEM) were used to analyze the crystal structure, surface morphology and characteristics, respectively. NiCo2O4 exhibited better electrocatalytic activity and stability for methanol oxidation than CuCo2O4 in 1 M KOH with 0.5 M methanol, and conducted to part II with this result.
In part II, NiCo2O4 nanoparticles/graphene quantum dots (GQDs) were synthesized via a one-step hydrothermal method and applied to methanol oxidation. X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM) and field emission transmission electron microscope (FE-TEM) were used to analyze the crystal structure, surface morphology and characteristics, respectively. With increasing the quantity of GQDs, thermogravimetric analysis (TGA) was also carried out to confirm the weight ratio of GQDs in the as-synthesized electrocatalyst. The NiCo2O4/GQDs exhibited excellent electrocatalytic activity for methanol oxidation in alkaline solution. NCO/G2 demonstrated a lower onset potential 0.34 V and superior current density of 103.8 A/g with good retention performance in 1 M KOH with 0.5 M methanol. The results of above analysis might be beneficial for development of direct methanol fuel cell based on non-Pt electrocatalysts.

摘要 i
Abstract ii
目錄 iii
圖目錄 v
表目錄 viii
第一章 緒論 1
1.1 前言 1
1.2 研究動機 2
1.3 燃料電池簡介 2
1.3.1 燃料電池的發展 2
1.3.2 燃料電池的特點 3
1.3.3 燃料電池的種類 4
1.4 直接甲醇燃料電池 7
1.4.1 直接甲醇燃料電池基本原理 7
1.4.2 直接甲醇燃料電池基本構造 8
1.4.3 甲醇在陽極的反應途徑及毒化問題 9
1.4.4 鹼性直接甲醇燃料電池 13
1.5 直接甲醇燃料電池之陽極觸媒發展 14
1.5.1 陶瓷氧化物觸媒材料 14
1.5.2 過渡金屬族觸媒材料 15
1.5.3 單一或多重過渡金屬氧化物觸媒材料 19
1.5.4 尖晶石結構過渡金屬氧化物觸媒材料 22
1.5.5 尖晶石結構過渡金屬氧化物(NiCo2O4)/碳材複合觸媒材料 25
1.6 石墨烯量子點(Graphene quantum dots，GQDs) 28
1.6.1 石墨烯量子點性質 28
1.6.2 石墨烯量子點之製備方法 29
1.6.3 石墨烯量子點之電化學應用 30
1.7 電化學原理與方法 33
1.7.1 循環伏安法原理(Cyclic voltammetry，CV) 33
1.7.2 安培法原理(Amperometry) 34
1.8 儀器原理 35
1.8.1 場發射掃描式電子顯微鏡(Field emission-scanning electron microscope，FE-SEM) 35
1.8.2 穿透式電子顯微鏡(Transmission electron microscope，TEM) 36
1.8.3 X光繞射分析儀(X-ray diffraction，XRD) 37
第二章 實驗方法與步驟 39
2.1 實驗藥品 39
2.2 實驗儀器 39
2.3 實驗步驟 40
2.3.1 實驗架構圖 40
2.3.2 電極前處理 41
2.3.3 材料合成 41
2.3.4 材料微結構與特性分析架構圖 42
2.3.5 DMFC電性分析 42
第三章 結果與討論 44
3.1 CuCo2O4與NiCo2O4之探討 44
3.1.1 CuCo2O4與NiCo2O4之X光繞射分析(X-ray diffraction，XRD) 44
3.1.2 CuCo2O4與NiCo2O4之表面形貌(Field emission scanning electron microscope，FE-SEM) 45
3.1.3 CuCo2O4與NiCo2O4之表面形貌(Field emission tranmission electron microscope，FE-TEM) 47
3.1.4 CuCo2O4與NiCo2O4之元素分析(X-ray energy dispersive spectrometer，EDS) 48
3.1.5 CuCo2O4與NiCo2O4陽極觸媒之電化學特性探討 49
3.2 NiCo2O4/石墨烯量子點複合材料之探討 56
3.2.1 NiCo2O4/GQDs複合材料之X光繞射分析(X-ray diffraction，XRD) 56
3.2.2 NiCo2O4/GQDs複合材料之表面形貌(Field emission scanning electron microscope，FE-SEM) 57
3.2.3 NiCo2O4/GQDs複合材料之表面形貌(Field emission tranmission electron microscope，FE-TEM) 61
3.2.4 NiCo2O4/GQDs複合材料之元素分析(X-ray energy dispersive spectrometer，EDS) 64
3.2.5 NiCo2O4/GQDs複合材料之熱重分析(Thermo Gravimetry Analyzer，TGA) 68
3.2.6 NiCo2O4/GQDs複合陽極觸媒之電化學特性探討 69
第四章 結論及未來展望 75
4.1 結論 75
4.2 未來展望 75
第五章 參考文獻 76

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