三嗪基聚合物半导体的设计合成及光催化性能研究

The conversion of solar energy into clean fuels such as hydrogen or methanol still requires significant improvements of high-efficiency photocatalysts, which are featured inexpensive, facilely synthesized, earth-abundant and of relatively low toxicity properties. It is considered as a revolutionized direction to investigate organic photocatalyst, with the goal of developing suitable positions of band edges and aimed structures/functions. The optimization of the synthetic conditions, chemical structures and optical properties, as well as charge separation and transport, will be examined in details for the photocatalytic matrix that coupling a chromophore with a triazine-based derivative. The effect of chromophore groups for the adjustment of HOMO/LUMO positions will be explored to meet the requirements of photoredox potentials with accompanying the photocatalytic performances. Therefore, it is able to study the relationship between structure and performance, and thus to illustrate the mechanism of photocatalytic reactions including photocatalytic water splitting and CO2 reduction. This demonstration offers possibility from the experimental basis and theoretical guidance for the design and preparation of relevant polymer photocatalysts. It is of great significance to improve the efficiency of photocatalytic water splitting and CO2 reduction, furthermore promote the practical applications in the conversion of solar to fuels.

研发廉价、低毒、地壳丰富元素组成的高效光催化剂是实现太阳能转化为可运输清洁能源（氢气，甲醇等）的关键之一。设计、合成能带位置合适和具有特定结构与功能的有机半导体光催化剂是一个新研究方向。本项目中提出通过分子设计将发色基团与三嗪基骨架进行偶联聚合，详细研究这种聚合物半导体的优化制备、分子结构、光吸收特性、表面状态以及光生载流子的分离和界面转移。探讨发色基团对三嗪基聚合物半导体材料能带结构的影响以及能带位置与光催化反应的氧化还原电势的匹配问题，结合光催化反应的性能评价结果，揭示催化剂结构-性能之间的构-效关系，阐明三嗪基聚合物半导体的光催化作用机制和反应机理，为其他聚合物光催化剂的设计合成提供实验依据和理论指导。该项目丰富光催化材料的研究内容，对太阳能光催化分解水制氢和二氧化碳还原具有重要科学研究价值和应用前景。

研发廉价、低毒、高丰度元素组成的高效光催化剂是实现利用太阳能解决能源与环境问题的关键之一。本项目将三嗪基等碳氮共轭聚合物光催化材料作为研究对象，以催化体系的设计合成和功能导向型后修饰为研究思路，在分子尺度上筛选前驱体，优化反应条件与聚合过程，实现对材料的能带结构、孔结构等性质的调控，拓展光催化剂的可见光吸收范围，促进光催化过程中光生电子空穴分离与传输、反应物传质等过程；改变表面官能团结构与担载贱金属，优化材料表面电子结构，增强表面动力学过程；初步探索实验室放大工艺，通过将纳米结构氮化碳固载于玻璃珠上，构建流动相光催化反应体系，实现了精细化学品光催化选择性合成放大制备。立项以来，设计制备了多种碳氮基有机聚合物光催化材料，并应用于光解水、光催化还原二氧化碳以及光催化有机合成等多个领域，获得1项实验室级光催化放大技术。该项目在碳氮有机光催化材料的设计调控、构效分析和光催化放大工艺开发等方面进行了较为深入的研究，为后续相关研究的开展奠定基础。