超薄纳米碳基全固态Z型光解水催化剂的构筑及催化机理研究

Photocatalytic water splitting is one of the most promising solutions for solving the energy crisis and environmental pollution. Z-scheme photocatalytic system is easy to realize the photocatalytic water splitting due to its low light excitation energy, strong reduction and oxidation activities of photo-induced electrons and holes, respectively. To increase the interface area and electronic coupling of recent all-solid-state Z-scheme photocatalytic systems, novel all-solid-state Z-scheme photocatalytic system (g-C3N4/C/Bi2WO6) will be constructed. In this photocatalytic system, ultra-thin nanocarbon will be used as the electron mediator, and ultra-thin g-C3N4 and Bi2WO6 nanosheets will be chose as the catalyst units. The regulation rules induced by the synthesis condition and composition of electron mediator and catalyst units will be studied and the regulation models of the photocatalyst composition and structure will be built. In this project, the impacts of the proportion of each component, interface structure, and electronic structure on the electron transport of the photocatalysts will also be investigated. Furthermore, in order to understand the relationships between composition and structure of photocatalysts and their photocatalytic performances, the effects of the composition and interface structure of photocatalysts as well as the photocatalytic reaction conditions on the photocatalytic water splitting activity will be studied. The synergetic mechanism of photocatalytic performance enhancement will be illustrated. This project will be acted as a solid theoretical basis for construction of the all-solid-state Z-scheme photocatalytic system with high efficiency and low cost.

太阳能光解水技术是解决能源危机与环境污染最理想途径之一。Z型光催化体系具有光激发能量低和光生载流子氧化还原能力强等优点，更易实现水的全光分解。本项目针对全固态Z型光催化体系存在的界面接触面积小、电子耦合作用弱等问题，拟选用超薄纳米碳作为电子传输介质，超薄g-C3N4、Bi2WO6纳米片作为活性单元，构筑新型全固态Z型g-C3N4/C/Bi2WO6光催化剂，深入研究反应条件以及构建单元的组成结构对全固态Z型光催化剂的调控规律，建立光催化剂组成结构的调控模型；总结该类光催化剂构建单元组成比例、界面结构、电子结构等因素对于光生电子输运的影响规律；研究光解水过程中光催化剂组成比例与界面结构以及光催化反应条件对可见光光解水性能的影响，揭示该类超薄纳米碳基Z型光催化剂的组成、结构与性能之间的关系，阐明光催化性能增强的协同机制，为构筑高效、低成本全固态Z型光催化体系奠定坚实的理论基础。

开发高效稳定光解水催化剂以提高光催化分解水效率是解决能源危机与环境污染最理想途径之一。本工作开发了系列高催化活性、高稳定性二维全固态复合光催化剂，深入研究了反应条件以及构建单元的组成结构对光催化体系的调控规律，建立了体系的界面调控模型；研究了该类光催化剂中活性单元组成比例、界面结构、电子结构等因素对于光生电子与空穴激发、光生电子迁移行为及其激子寿命的影响，总结了该类光催化体系界面电荷迁移及其反应的动力学与热力学规律；并进一步研究了光催化剂的组成比例与表界面结构以及光催化反应条件对可见光光解水、降解有机物性能的影响，确定影响活性的关键因素；研究了光催化剂的组成、结构与性能之间的关系，建立光催化剂可见光催化机理模型，阐明光催化性能增强的协同机制。为理性设计合成高效可见光催化体系以实现高效光催化分解水、有机污染物降解提供新的策略。