臺灣博碩士論文加值系統

本研究以鈦箔經電漿電解氧化法，利用六偏磷酸鈉和氫氧化鈉作為電解液，控制純銳鈦礦相之二氧化鈦生成，且評估染料敏化太陽能電池之應用，並探討影響二氧化鈦生成結晶相、表面微結構、親水性等因素為何。
若以0.04 M六偏磷酸鈉和0.125 M氫氧化鈉作為電解液，於鈦塊材及鈦箔反應基材，固定電流頻率980 Hz，佔空比10%，反應10分鐘，電解液溫度2℃，藉由改變不同反應電壓進行電漿電解氧化法，可製備出純銳鈦礦二氧化鈦。更進一步調整電解液濃度為(1) 0.02 M六偏磷酸鈉和0.125 M氫氧化鈉及(2) 0 M六偏磷酸鈉和0.125 M氫氧化鈉，於鈦箔反應基材進行相同製程，可知改變反應基材、電解液成分及電源參數可以進一步控制火花放電情況，影響氧化膜的生長，達到控制純相銳鈦礦產生。
比較鈦箔及鈦塊材之差異，可以得知氧化膜結晶相、厚度與粗糙度之差異變化不大；兩者最明顯之差異為鈦塊材的擊穿電壓為250 V，鈦箔擊穿電壓為200 V，因此，鈦箔之反應電流流經試片表面時間較久，膜層具有較高的表面能，可使鈦箔相較於鈦塊材，其表面孔洞較大及親水性優異等性質。
應用方面評估，染料敏化太陽能電池之光電效率與二氧化鈦光電極、染料分子及氧化還原電解質相關。以六偏磷酸鈉和氫氧化鈉作為電解液，可生成純銳鈦礦二氧化鈦，而以氫氧化鈉為電解液之電漿電解氧化之氧化膜結晶相為銳鈦礦與金紅石，因兩者表面微結構差異，影響染料吸附量，故光電轉換效率於氫氧化鈉為電解液條件下較佳。未來若能改善純銳鈦礦二氧化鈦之微結構，形成微奈米之孔洞，以利染料吸附比表面積提升，有望增強其光電轉換效率，於染料敏化太陽能電池應用之潛力提升。

In this research, titanium dioxide was produced by plasma electrolyte oxidation on Ti foil substrate with the electrolytic solution of sodium hexametaphosphate (NaPO3)6 and sodium hydroxide (NaOH) to control the formation of titania in the pure anatase phase and to evaluate the application of dye-sensitized solar cells. The formed titania was explored in the crystalline phase, surface microstructure, hydrophilicity and other factors.
Using the electrolyte of 0.04 M sodium hexametaphosphate and 0.125 M sodium hydroxide, with Ti bulk and Ti foil as reaction substrates, fixed the current frequency, duty cycle, reaction time and temperature of electrolyte was 980 Hz, 10%, 10 minutes and 2℃, respectively. By controlling the reaction voltage in plasma electrolyte oxidation method, the pure anatase titanium dioxide can be prepared. Furthermore, 0.02 M sodium hexametaphosphate with 0.125 M sodium hydroxide and 0 M sodium hexametaphosphate with 0.125 M sodium hydroxide were modified to carry out the same previous process on Ti foil reaction substrate. From the results of modification, we can know that changing the substrate, composition of electrolyte and power parameter can control the phenomenon of spark discharge to affect the growth oxide layer and control the existence of the pure anatase titania.
Compare the difference between Ti foil and Ti bulk, it can be seen that the oxide layer of the crystalline phase, the thickness and roughness were similar. The most obvious difference is when the breakdown voltage of Ti bulk is 250 V while the breakdown voltage of Ti foil is 200 V. The time of reaction current on Ti foil and flow through the specimen longer than Ti bulk, thus the oxide film has a higher surface energy to obtain the bigger surface pore size and excellent hydrophilicity.
In the application evaluation, the photoelectric conversion efficiency of dye-sensitized solar cells is related to titanium dioxide photoelectrode, dye molecules and redox electolytes. When the sodium hexametaphosphate and sodium hydroxide are used as electrolytes, the pure anatase titanium dioxide is produced. When the sodium hydroxide was used as electrolyte, the crystalline phase of titanium dioxide layer were anatase and rutile. Due to the difference of the surface microstructure, the amount of the dye adsorption was affected. Therefore, the photoelectric conversion efficiency is more excellent under the sodium hydroxide electrolyte. If the microstructure of pure anatase titanium dioxide can be improved to form micro-nanopores and to increase the adsorption specific surface area of the dye in the future, the photoelectric conversion efficiency will be enhanced which can increase the potential of dye-sensitized solar cells.

誌謝 i
摘要 iii
Abstract iv
目次 vi
表目次 ix
圖目次 x
第一章 緒論 1
1.1 前言 1
1.2 研究動機 2
1.3 研究目的 3
第二章 理論背景與文獻回顧 4
2.1 電漿電解氧化法理論背景 4
2.2 染料敏化太陽能電池之工作原理及組成元素 9
2.3 電漿電解氧化法於鈦塊材或鈦箔製備二氧化鈦塗層之文獻 15
2.3.1 以鈦塊材及鈦箔作為反應基材 15
2.3.2 使用六偏磷酸鈉作為電解液 21
2.4 不同製程方法製備二氧化鈦應用於染料敏化太陽能電池之文獻 25
第三章 研究方法 28
3.1 實驗流程 28
3.2 Ti基材之準備 29
3.3 電漿電解氧化法製備二氧化鈦之方法 30
3.4 染料敏化太陽能電池組裝 31
3.4.1 染料及電解液配置 31
3.4.2 元件組裝 31
3.4.3 光電轉換效率量測 32
3.5 分析儀器 33
3.5.1 X光繞射分析儀 33
3.5.2 冷場發射掃描電子顯微鏡 33
3.5.3 表面粗度測定儀 34
3.5.4 傅立葉轉換紅外線光譜儀 34
第四章 結果 35
4.1 鈦箔基材分析 35
4.2 以電漿電解氧化法於實驗組鈦箔及對照組鈦塊材以0.04 M六偏磷酸鈉加0.125 M氫氧化鈉作為電解液製備二氧化鈦之差異 37
4.2.1 以鈦箔作為反應基材 37
4.2.1.1 二氧化鈦膜層結晶相及相對強度之分析 37
4.2.1.2 二氧化鈦膜層表面及橫截面微結構分析 40
4.2.1.3 二氧化鈦膜層之接觸角 46
4.2.2 以鈦塊材作為反應基材 47
4.2.2.1 二氧化鈦膜層結晶相及相對強度之分析 47
4.2.2.2 二氧化鈦膜層表面及橫截面微結構分析 50
4.2.2.3 二氧化鈦膜層之接觸角 55
4.2.3 二氧化鈦/鈦箔應用於染料敏化太陽能電池測試結果 56
4.3 改變電解液組成 57
4.3.1 以0.02 M六偏磷酸鈉加0.125 M氫氧化鈉作為電解液 57
4.3.1.1 二氧化鈦膜層結晶相及相對強度之分析 57
4.3.1.2 二氧化鈦膜層表面及橫截面微結構分析 60
4.3.1.3 二氧化鈦膜層之接觸角 65
4.3.2 以氫氧化鈉作為電解液 66
4.3.2.1 二氧化鈦膜層結晶相及相對強度之分析 66
4.3.2.2 二氧化鈦膜層表面微結構分析 71
4.3.2.3 二氧化鈦膜層之接觸角 74
4.3.3 二氧化鈦/鈦箔應用於染料敏化太陽能電池測試結果 76
第五章 討論 78
5.1 電漿電解氧化法以鈦塊材與鈦箔作為反應基材對二氧化鈦結晶相與微結構之異同 78
5.2 改變電解液中六偏磷酸鈉濃度對結構造成的變化 83
5.3 二氧化鈦之結構對光電轉換效率的影響 90
第六章 結論 96
參考文獻 97

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