基于新型锚定基团的染料敏化光解水系统研究

Dye-sensitized water splitting system is used to capture solar energy and provide solar fuel as a clean energy alternative. In a water-splitting photoelectrochemical dye-sensitized photoanode, an anchoring group is used to connect a chromophore and a semiconductor substrate, providing a pathway for interfacial charge transfer. Traditionally, carboxylate and phosphonate groups are used as the anchoring group; this limits the materials that can be used in the photoanode. Also, the carboxylate group is unstable in water while the phosphonate group is insufficient for efficient charge transfer. As a result, it is essential to find new anchoring groups for water oxidation in a water-splitting photoelectrochemical cell. Limited research has been devoted to finding new anchoring groups for water splitting system. The main purpose of this project is to explore new anchoring groups to substitute carboxylate and phosphonate groups in a water oxidation electrode from combined experimental and theoretical studies, providing an alternative way to enhance efficiency and stability of water-splitting photoelectrochemical dye-sensitized photoanode.

染料敏化光解水系统能够利用太阳能有效地提供清洁能源。锚定基团作为染料敏化光解水系统电极的重要组成部分，连接电极中的载色体和半导体基底，影响了光解水系统的稳定性与电荷传输性能。传统上的染料敏化光解水系统以羧基或者磷酸基等基团作为锚定基团；但是这些基团稳定性与电荷传输性低，限制了染料敏化光解水系统的产氢和产氧效率。目前对光解水系统中新型锚定基团的研究开展很少；传统的染料敏化光解水系统研究工作忽视了通过对新型锚定基团的研究提高染料敏化光解水系统性能。本项目将新型锚定基团作为切入点，在模拟结果的指导下进一步提高染料敏化光解水系统的光电性能和仪器稳定性。本项目研究成果将加深人们对新型光解水系统结构与机理的理解，为新型光电材料的发展提供研究思路。

本项目研究了水相环境中染料敏化系统的新型锚定基团，探索基于新型锚定基团的染料敏化光阳极原子和电子层面精确结构与性质，探讨水相环境中基于新型锚定基团的染料敏化光电极光电转换机理和新型锚定基团在光解水系统的应用可能性。第一，通过第一性原理计算，得到了一系列含有新型锚定基团的染料敏化光解水系统精确原子和电子结构，揭示了新型锚定基团在光解水系统中的工作机理；第二，实验验证了含有新型锚定基团的水相环境染料敏化系统，创新性地提出了新型锚定基团可以应用于钛氧团簇和金属卤化物钙钛矿材料，检验了新型锚定基团/钛氧团簇和新型锚定基团/钙钛矿等复合体系在水相环境中的工作效果；第三，发现了新型锚定基团可以辅助染料敏化体系的光致异构、分子聚合和光控电流方向改变现象。