Development of Phthalocyanine-based Materials for Artificial Photosynthesis and Dye-sensitized Solar Cells

酞菁是一類四吡咯大環化合物，在紫外可見光區有很強的吸收（分別為350 nm 處的Soret帶和670 nm處的Q帶），具有有趣的光電性質。本論文描述了一系列基於酞菁的功能性材料的合成，表征，光物理性質及其在人工光合作用與染料敏化太陽能電池中的應用。第一章概述了酞菁的基本合成方法與性質，詳細介紹了“捆綁”和ABAB型酞菁的合成。本章後半部分介紹了酞菁在構築人工光合作用模型及作為染料敏化太陽能電池的光敏劑方面的應用。第二章報道了一系列酞菁-卟啉與酞菁-氟硼熒二吡咯化合物的合成，光譜表征以及光物理性質。卟啉/氟硼熒二吡咯與酞菁的連接能夠擴寬其光譜吸收，從而增強太陽光採集能力。咪唑修飾的C60可與酞菁中心軸向配位，與其構築人工光合作用模型。吸收及熒光光譜證明了分子內及分子間的光誘導激發態能量和電子轉移。在該類體系中，卟啉/氟硼熒二吡咯單元作為光合作用的天線，採集光能並將激發態能量傳遞給酞菁，接著，軸向配位的C60可通過電子傳遞將激發態的酞菁淬滅。作為上一工作的拓展，第三章描述了一個相關的由二茂鐵-酞菁-氟硼熒二吡咯化合物與軸向配位的C60構築的超分子人工光合作用模型。其中，二茂鐵作為一個電子給體，能夠通過光誘導電子轉移淬滅酞菁的熒光。當二茂鐵-酞菁-氟硼熒二吡咯化合物與富勒烯配位后，光激發硼熒二吡咯單元，產生的酞菁-富勒烯電荷分離態能夠被二茂鐵向酞菁的空穴轉移而穩定，從而減緩電荷重組的速率。第四章報道了一系列基於酞菁的多髮色團光敏劑，該類光敏劑具有共價或非共價的錨基團，并研究了其在染料敏化太陽能電池方面的應用。卟啉/氟硼熒二吡咯單元的引入彌補了酞菁在400-500 nm處的吸收和光反應空缺。擁有共價鍵錨基團的光敏劑效率相對較高，製得的染料敏化電池表現出了進紅外的光吸收能力。第五章報道了一系列具有給體-π-受體結構的推拉式酞菁光敏劑的合成，光譜表征，光物理性質及其在染料敏化太陽能電池方面的應用。同時製備了另一系列的具有兩個錨基團的trans A2B2型酞菁光敏劑。酞菁環上的八個2,6-二甲基苯氧基能夠促進該類酞菁合成，并防止酞菁環的自聚集，從而提高化合物的溶解度。分佈在酞菁環對面的電子給受體估計能夠促進電子由激發態的光敏劑注入二氧化鈦。本章後部分報道了所製備的染料敏化太陽能電池的光轉化效率。論文的最後附有新合成化合物的氫譜和碳譜圖。Phthalocyanines are tetrapyrrolic macrocycles with intense absorption in the UV-visible region (ca. 350 and 670 nm for the Soret and Q bands, respectively) and intriguing optoelectronic properties. This thesis describes several series of phthalocyanine-based functional materials for potential applications in artificial photosynthesis and dye-sensitized solar cells (DSSCs), including their synthesis, characterization, photophysical properties and performance in these applications.Chapter 1 presents a brief overview of the synthetic methods and properties of phthalocyanines, focusing on the “side-strapped” and ABAB-type analogues. The applications of phthalocyanines as building blocks of artificial photosynthetic models and photosensitizers for DSSCs are also reviewed.Chapter 2 describes the synthesis, spectroscopic characterization, and photophysical properties of a series of phthalocyanine-porphyrin and phthalocyanine-boron dipyrromethene (BODIPY) conjugates. The conjugation of BODIPY/porphyrin moieties to a phthalocyanine core can extend the absorptions in the solar spectrum, thereby enhancing the light harvesting. A C60-imidazole (C60-Im) moiety has been axially coordinated to the phthalocyanine core of the conjugates to construct artificial photosynthetic models. The photoinduced excitation energy transfer (EET) and electron transfer (PeT) processes have been studied by electronic absorption and steady-state fluorescence spectroscopic methods. In these systems, the BODIPY/porphyrin moieties serve as the antennas to capture the light and transfer the energy to the phthalocyanine core, which is then quenched by the axially bound C60-Im moiety by electron transfer.As an extension of the previous work, Chapter 3 presents a related model with two additional ferrocene moieties. As an electron donor, ferrocene also quenches the fluorescence of the phthalocyanine via a PeT process. Upon binding to the fullerene unit and excitation at the BODIPY moieties, the charge-separated state generated has been stabilized by a hole migration from ferrocene to phthalocyanine, and this has slowed down the process of charge recombination.Chapter 4 reports the preparation of a series of phthalocyanine-based multi-chromophore photosensitizers with covalent or noncovalent anchoring groups for the application in DSSCs. The introduction of BODIPY/porphyrin moieties can complement the absorption and photo-responsive gap of phthalocyanines at 400-500 nm. It has been found that the photosensitizers with covalent anchoring groups are more efficient and the resulting devices show improved light-capturing ability up to the near-IR region.Chapter 5 presents the synthesis, spectroscopic characterization, and photophysical properties of a series of push-pull phthalocyanines with a donor-π-acceptor (D-π-A) structure, as well as their application in DSSCs. Another series of trans A2B2-typeChen, Xiaofei.Thesis Ph.D. Chinese University of Hong Kong 2016.Includes bibliographical references (leaves ).Abstracts also in Chinese.Title from PDF title page (viewed on …).Detailed summary in vernacular field only.Detailed summary in vernacular field only.Detailed summary in vernacular field only.Detailed summary in vernacular field only.Detailed summary in vernacular field only.Detailed summary in vernacular field only.Detailed summary in vernacular field only