本研究利用密度泛函理論計算人工光合作用中光陽極材料之性質與反應過程之探討，其中研究的材料為無機半導體釩酸鉍(BiVO4)和單核釕基催化劑Ru(bda)(6-F-isq)2 (bda=2,2'-聯吡啶-6,6'-二羧酸, isq=異喹啉, F=氟)。BiVO4是近年備受矚目的半導體材料，其可吸收可見光、良好導帶邊緣位置且系統反應穩定。而釕基催化劑在水氧化領域中一直具有良好的反應速率。因此本篇欲結合具良好導帶邊緣且穩定之BiVO4與具有高效反應速率之Ru(bda)(6-F-isq)2，期望複合型催化劑能結合兩者優點，使陽極析氧反應速率有進一步的發展。
本研究第一部分先以單斜晶系白鎢礦之釩酸鉍(ms-BiVO4)為初始材料，建立單位晶胞模型後，進行幾何結構最佳化。接著分別取代第一和第二層的金屬原子，計算電子能帶結構和雜質形成能，以推斷鋯(Zr)實際取代之位置。第二部分利用軟體Gaussian 09計算Ru(bda)(6-F-isq)2的基礎性質，包括分子軌域圖以及紫外/可見光之吸收光譜，以驗證模型的合理性。第三部分將Ru(bda)(6-F-isq)2連接BiVO4進行結構最佳化，得到最低能量時的穩定結構後，加入水分子逕行析氧反應的過渡態搜尋，再經內座標反應系統驗證過渡態結構。最後求得逐步之反應速率常數，確認反應路徑。
總結以上，經研究本篇第一部分發現由理論推估的雜質形成能量在Zr取代Bi時較小，表示取代的機會較高。第二部分計算確認連接BiVO4之Ru(bda)(6-F-isq)2 其UV/Vis光譜相對未連接之Ru(bda)(6-F-isq)2明顯往紅外光方向移動，推斷連接BiVO4後可以改善Ru(bda)(6-F-isq)2之吸收光譜。第三部分計算析氧反應之過渡態的過程中，發現與未連結BiVO4之Ru(bda)(6-F-isq)2比較，整體反應最困難的步驟在將OH*裂解的過程，判斷原因可能為氫離子單獨存在反應中的機率極低，並且本研究未加入溶劑效應進行計算，所以模擬的反應速率較慢，在實驗的過程中會有溶劑的影響同時會加入助催化劑來改善。

This study uses density functional theory (DFT) to calculate the properties of the photoanode and its oxygen evolution rate in the artificial photosynthesis. The photoanode consists of a semiconductor bismuth vanadate (BiVO4) and a mononuclear ruthenium based catalyst Ru(bda)(6-F-isq)2 (where bda = 2,2'-bipyridine-6,6-dicarboxylic acid and isq = isoquinoline). This is because BiVO4 has a suitable conduction band edge to absorb light and the Ru(bda)(6-F-isq)2 has the tendency to promote the oxygen reaction rate.
In the first part of this thesis, monoclinic scheelite (ms-BiVO4) is used as the starting material to establish the unit cell model with optimized geometry. After calculation of the electron band structure and the impurity forming energy, the metal atoms can be replaced at the different layers. The location of the replacement of Zr is inferred. The second part uses the software Gaussian 09 to calculate the basic properties of Ru(bda)(6-F-isq)2 to verify the rationality of the model. In the third part, Ru(bda)(6-F-isq)2 is connected to BiVO4 for the transition state search in the oxygen evolution reaction. After verifying the transition state structure by the internal coordinate reaction system, the reaction rate constant can be obtained and the reaction path will be confirmed.
It was found that when Bi atoms were replaced by Zr, the theoretically estimated impurity formation energy was small and the probability of substitution was high. The second part of the calculation confirmed that the absorption spectrum of the original Ru(bda)(6-F-isq)2 can be improved after the BiVO4 is attached. In the third part of the calculation of the transition state during the oxygen evolution reaction, it was found that the most difficult step in the overall reaction is the process to cleave the OH*, presumably due to the fact that hydrogen ions rarely present alone. This study did not consider the solvent effect in the first principles calculation, so the predicted reaction rate is slower.

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