2019-05-062024-05-18https://scholars.lib.ntu.edu.tw/handle/123456789/699999摘要：化石燃料的消秏速度已超過其生成速度，化石燃料的短缺可能會出現在可預見的未來，化石燃料是藉由燃燒來釋放能量，燃燒時所生成的主要產物為二氧化碳，二氧化碳被認為是造成地球氣侯異常的主因，一般認為發展再生能源應可解決當前的能源問題。於再生能源中，以太陽能具有最高的普遍性及永久性，吸引了眾多的研究目光，除了將太陽能轉為電能外，另一可行的方式是將其轉化為可儲存的化學能。本計畫預計使用有機共軛分子作為光觸媒來將光能轉化為人類可利用的化學能，第一種方式是將水裂解為氫氣及氧氣，第二種是將二氧化碳轉化為有機小分子。在水裂解反應上會以單一催化或協同催化系統來進行測試，主要的差別在於單一催化系統是以單一催化劑來進行水的氧化及還原反應，而協同催化系統中，p-型半導體會負責將質子還原成氫氣，n-型半導體則會將水氧化為氧氣及質子，p-型及n-型半導體間需建立起p-n接合介面，以增加協同系統的催化效率，單一催化系統主要會以有機共軛高分子作為催化劑，而協同催化系統則會採用兩種半導體混摻的方式，可為共軛分子或高分子，水裂解反應的光催化劑所需滿足的能階條件會以DFT計算來驗證，以作為設計及合成催化劑的依據，有機共軛高分子的幾何形狀亦會被調控，期待建立固態形貌與催化效率及穩定性之關聯性。在固碳反應上，同樣會以有機共軛高分子作為光觸媒，預計進行的反應有二氧化碳還原為甲烷、二氧化碳轉化為胺基酸及二氧化碳轉化為水楊酸，均相及非均相反應的差別亦會被研究且討論，DFT計算同樣會使用來作為催化劑設計且合成的依據且計算其反應機制，尤其是針對化合物間的電子轉移及電子自旋對於碳–碳化學鍵形成的影響，期待對以電子轉移來形成化學鍵有更深一層的了解。<br> Abstract: The depletion rate of fossil fuels over its production rate has been speculated. The shortage of fossil fuels may occur in the near future. To extract energy from fossil fuels relies on combustion and the primary product of combustion is carbon dioxygen, which is believed to be the major factor bringing on the climate disorder at the present time. Renewable energy may be a solution to these problems. As a result of accessibility and permanence, solar energy has attracted enormous research attention. In addition to directly converting solar energy into electricity, another promising approach is to storable chemical energy which the human race is capable of using. This research proposal aims at utilizing organic photocatalysts in water splitting and CO2 conversion under illumination. For water splitting, single or synergistic catalytic system will be examined. In the single catalytic system, various organic conjugated polymers will be tested in the catalytic reactions. As for the synergistic system, the combination of p-type and n-type organic semiconductors will be adopted. P-type semiconductors are responsible for proton reduction to hydrogen and n-type semiconductors are in charge of water oxidation to oxygen and proton. The semiconductors applied in the synergistic system can be organic conjugated molecules or polymers. DFT calculation will be carried out to estimate whether the proposed organic photocatalysts fulfill the energetic requirements for water splitting and serve as guidelines to design the catalysts. Moreover, the geometrical shape of organic conjugated polymers will be modulated in order to build the relationship between solid-state morphology and catalytic efficiency/stability. For CO2 conversion, organic conjugated polymers will be employed as the catalyst as well. The tested reactions include CO2 reduction to methane, CO2 conversion to amino acid, and CO2 conversion to salicylic acid. The difference between homogeneous and heterogeneous catalysis for these reactions will be investigated. Similarly, DFT calculations will be employed in guiding the design of catalysts and computing the reaction mechanisms, in particular for the electron transfer between reactants and the influence of electron spin towards C–C formation.水裂解反應二氧化碳固碳反應有機半導體有機光觸媒共軛高分子共軛有機框架DFT計算高分子形貌均相反應非均相反應water splittingCO2 fixationorganic semiconductorsorganic photocatalystsconjugated polymersconjugated organic frameworksDFT calculationpolymer morphologyhomogeneous reactionheterogeneous reaction