多氨基苯基卟啉/石墨烯团簇的构建及其用于人工光合作用的研究

The increasing concentration of CO2 in atmosphere is the most serious environmental concern of global warming and climate change. Therefore, it is highly desirable to find a way for conversion of CO2 into sustainable energy production. Biomimetic artificial photosynthesis has recently gained attention as one of the most promising and compelling approaches for reduction of CO2 to fuel using solar energy, which can ease global energy and environmental issues simultaneously. In artificial photosynthesis, it is desirable to harvest and convert as much light into chemical energy as possible for maximized conversion efficiency. Thus, the design and fabrication of new materials for highly efficient artificial photosynthesis are required. These materials should be capable to serve by increasing the light-harvesting capacity and by increasing the rate at which the reaction center receives excitation energy. Here, we present a novel strategy to fabricate porphyrin-graphene with highly efficient light-harvesting and photocatalytic properties, by imitating the elaborate architecture of original plant corpus and by covalently linking of donor-acceptor. The composite realizes the synergy effect of light-harvesting and electron transfer improvements, and becomes a major advance in photosynthesis to develop novel and efficient photocatalysts. The special design of radial structure provides the way to develop the materials with promising photocatalytic, optical, and electronic properties. Furthermore, the synthetic covalent bond between donor and acceptor endows materials with an extremely high electron transfer efficiency. Therefore, the effective structure design and simple covalent synthesis route are intended as a guide for the engineers and scientists who are engaged in the rational design of high conversion efficiency materials for the improvement of artificial photosynthesis.

人工光合作用是利用物理和化学等技术模拟自然界的光合作用过程，储存和转化太阳能，吸收和固定二氧化碳，制造有机物和氧气。人工光合作用的研究对解决人类面临的粮食不足、能源枯竭和温室效应等问题有重要意义，但作为一种新型利用太阳能的方法，它存在着光能-电能-化学能过程转换效率低的问题。设计新型的天线-光反应中心，对提高人工光合作用的效率起关键作用。本项目拟将材料、结构和连接方式的各自优势相结合，制备新型的天线-光反应中心。选择具有良好光电性能的卟啉-石墨烯电子给受体组合，通过共价键连接实现快速的光致电荷分离速率。借鉴叶绿素的结构，将卟啉-石墨烯复合材料制备成放射状的团簇结构，来减少入射光的反射和增加陷光效应，从而提高光利用率。本研究拟揭示卟啉-石墨烯复合材料的连接方式和结构对提高人工光合作用效率的协同机制，得出提高人工光合作用效率的体系设计与性能调控的方法，对人工光合作用的研究与开发具有积极的意义。

人工光合作用的研究对解决人类面临的粮食不足、能源枯竭和温室效应等问题有重要意义，但作为一种新型利用太阳能的方法，它存在着光能-电能-化学能过程转换效率低的问题。设计新型的天线-光反应中心，对提高人工光合作用的效率起关键作用。本项目提出并研究了材料、结构和连接方式的各自优势相结合，探索了有机小分子和石墨烯连接方式，石墨烯微观结构组装和多孔石墨烯材料制备。在此基础上，制备了新型的天线-光反应中心。用紫外-可见漫反射光谱、光电流、飞秒暂态吸收光谱、电化学阻抗等方法证明了材料的电子转移能力，揭示了连接方式和形貌结构参数对提高人工光合作用效率的机理，得出了提高人工光合作用效率的体系设计与性能调控的方法，本项目的实施对天线-光反应中心材料的设计以及对人工光合作用的研究与开发具有积极的意义。