奈米光電池及光引發電子轉移反應
Abstract
7
摘要
五種本實驗室裡合成出來的聯砒啶釕錯合物，被成功的做成光敏
性太陽能電池。光電流的產生率可用來探討此類釕錯合物在激發態
時，電子在配位基上的分佈情形，是否會影響電子由激發態注入到
TiO2 傳導帶上的效率。實驗結果顯示，當釕錯合物在激發態時，電子
密度分佈在含羧酸基的bpy 上的比例較多時，的確可以造成較好的光
電流值。同時我們也使用循環伏特安培計(CV)，來偵測此光電系統
中I3
－離子的產生速率，雖然在測量上受到了干擾而無法準確的估計
I3
－生成速率，但我們確定了可以利用逆反應來觀察電解液中I3
－離子
的生成速率。
利用TiO2 nano-particles 的特性，可以使Hemin 照光激發後，將
電子由激發態注入至TiO2 的傳導帶上，本身則被氧化成FeIII(P•＋)。當
有受質Guaiacol 存在時，會得到單電子的氧化物，再偶合得到雙聚物
3,3΄-dimethoxy-4,4΄-dihydroxy-biphenyl。此產物的生成更確定了ferric
cation-radical porphyrin (FeIII(P•＋)) 的形成。光激發活化血基質，是除
了以氧化劑、電化學方式之外，另一條活化血基質蛋白酵素的路徑。
8 Five ruthenium bipyridine type complexes have been incorporated into the dye-sensitized solar cell system. The results show the distribution of the electron density of the ruthenium complexes in the excited state will slightly alter the photo-to-current efficiency. When the carboxyl containing bipyridine has more electron density in the excited state, the photo-to-current values will increase. The Cyclic Voltammetry has been used to detect the production of the I3 － ion. Although Hemin has a very short-lived excited-state, it has photochemistry while absorbed onto nano-sized TiO2 particles. Upon excitation, Hemin injects one electron into the conduction band of titanium dioxide and oxidizes to FeIII(P•+). In the presence of substrate, Guaiacol, the major photoproduct is radical coupled dimer, 3,3΄-dimethoxy-4,4΄-dihydroxy-biphenyl. This result further supports the formation of ferric cation-radical porphyrin (FeIII(P•+)) upon excition. Photoinduced FeIII(P•+) formation is a new route to initiate iron-porphyrin catalysis.
8 Five ruthenium bipyridine type complexes have been incorporated into the dye-sensitized solar cell system. The results show the distribution of the electron density of the ruthenium complexes in the excited state will slightly alter the photo-to-current efficiency. When the carboxyl containing bipyridine has more electron density in the excited state, the photo-to-current values will increase. The Cyclic Voltammetry has been used to detect the production of the I3 － ion. Although Hemin has a very short-lived excited-state, it has photochemistry while absorbed onto nano-sized TiO2 particles. Upon excitation, Hemin injects one electron into the conduction band of titanium dioxide and oxidizes to FeIII(P•+). In the presence of substrate, Guaiacol, the major photoproduct is radical coupled dimer, 3,3΄-dimethoxy-4,4΄-dihydroxy-biphenyl. This result further supports the formation of ferric cation-radical porphyrin (FeIII(P•+)) upon excition. Photoinduced FeIII(P•+) formation is a new route to initiate iron-porphyrin catalysis.