本研究的目的為開發非碳(或氧化物)的觸媒並應用於氧氣析出反應，本研究首先使用不同過渡金屬摻雜的TiO2作為氧氣析出反應的觸媒。在材料的選擇上取代傳統用碳當載體，因為碳在高電位的操作下容易被腐蝕進而使觸媒脫落而失去活性，相反的，TiO2在強鹼且高電位的環境中能夠維持穩定不易被氧化，以TiO2取代碳當載體後改善載體腐蝕的問題。但是TiO2本身並不具有氧氣析出反應的催化活性，為了增加氧氣析出反應之催化活性，我們將不同的3d過渡金屬離子摻雜進入TiO2，一方面期望改善二氧化鈦導電性，另一方面希望提升氧氣析出反應的催化活性。
本實驗選擇Ni, Co, Fe以及Mn離子為單摻雜TiO2的摻雜物，而(Ni, Fe)為雙摻雜的摻雜物，經過電化學活性量測後發現，(Ni, Fe)雙摻雜的TiO2氧氣析出反應的催化活性最好，因此本實驗選擇(Ni, Fe)雙摻雜的TiO2為改質的目標，進行對(Ni, Fe)雙摻雜的TiO2更深入的研究與探討。
改質的方向大略分為提升活性點催化活性與增加活性點數目兩大類，本實驗初期嘗試改變組成以獲得最好的比例，經過測試之後發現Ni:Fe莫耳比例為3:1時有較好的催化活性，於是進行Ni:Fe = 6:2、3:1、1.5:0.5之間的活性比較，經過電化學活性測試後發現Ni:Fe = 6:2時的氧氣析出催化效能最好，於是後續皆會以Ni:Fe = 6:2的比例為基礎進行不同方式的改質，期望能更進一步增強觸媒的氧氣析出催化能力。
改質的方式為添加長鏈狀陰離子、氫氣處理以及使用二次水熱的方式成長觸媒，經過改質後，本實驗合成之觸媒NiFe LDH/TiNiFe在電流密度10 mA/cm2 時所需的電位對比純NiFe LDH少10 mV，而穩定性則是大幅優於純NiFe LDH，經過48小時的定電流測試發現觸媒活性並不會降低，成功改善活性以及穩定性的問題。

關鍵詞: 氧氣析出反應、水分解、二氧化鈦、摻雜、過渡金屬、高穩定性

In this work, 3d transition metal doped TiO2 was synthesized and used a catalyst for alkaline oxygen evolution reaction. Commercial catalyst usually uses carbon as support such as Ir/C and Ru/C. But during oxygen evolution reaction, carbon will be corroded seriously. So, catalyst will detach from carbon support cause efficiency of catalyst to decay very quickly. In order to overcome these problems, we develop TiO2 as a support because TiO2 is a very durable material in high potential region and high concentration alkaline electrolyte. However, TiO2 is not a good catalyst for oxygen evolution reaction and suffer from its poor conductivity. To solve these drawbacks, we synthesized different 3d transition metal doping TiO2 in this work. After electrochemical tests, we choose (Ni, Fe) dual doped TiO2 was chosen because of its potential for oxygen evolution reaction.
First of all, different different doping compositions of Ni and Fe were invesitaged, and it was found that Ni:Fe in molar ratio 3:1 showed the best oxygen evolution reaction performance. Next, different doping amounts of Ni to Fe, from 6:2, 3:1 to 1.5:0.5 were also evaluated, where Ni:Fe in 6:2 was the best composition for alkaline oxygen evoution.
Futhermore, we modified catalyst by adding long chain anion, hydrogen treatment and loading NiFe LDH on (Ni, Fe) dual doped TiO2. Finally, NiFe/TiNiFe perform better oxygen evolution reaction than pure NiFe LDH. At the current density reach 10 mA/cm2, the required potential of NiFe/TiNiFe was 10 mV less than for pure NiFe LDH. After 2-days chronopotentiometric stability test, NiFe/TiNiFe showed almost no decay during reaction and is more superior than NiFe LDH. Our work successfully solves activity and stability issue at the same time by an excessive dual doping approach.

Keyword: Oxygen evolution reaction, Water electrolysis, TiO2, Doping, Transition metal, High stability.

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