梯形太阳燃料光催化剂的设计制备与原位机理研究

光催化分解水制氢和CO2还原制备太阳燃料对于解决日益严重的能源和环境问题非常重要。异质结光催化剂的设计制备是该领域的研究热点，传统II型异质结虽然实现了光生空穴和电子的空间分离，但他们的氧化还原能力被降低。项目拟设计和制备基于氧化型与还原型光催化剂复合的梯形异质结光催化剂，并将其用于光催化产氢和CO2还原，该异质结可以克服传统II型异质结的缺陷，使系统具有最大的氧化还原能力。研究梯形异质结光催化剂组成、制备方法、表面和界面结构与性能的关系，通过光电子能谱、原子力显微镜和时间分辨荧光等原位技术研究光生载流子的界面转移机理。建立梯形异质结光催化剂的设计理论和制备方法，制备出高效稳定的梯形异质结太阳燃料光催化剂，阐明梯形异质结材料的组成、制备方法、形貌、微结构等对光催化性能的影响规律，揭示梯形异质结光催化剂的构-效关系和电荷转移机理。本研究将为新型太阳燃料光催化剂的设计与制备提供新的视野。

Photocatalytic H2 generation by water splitting and solar fuel production by CO2 reduction are very important for solving increasingly serious environmental pollution and energy crisis problems. Design and preparation of heterojunction photocatalyst are a research hotspot in photocatalysis. Traditional II heterojunction results in the separation of photogenerated electron and hole in space, but the reduction and oxidation ability of generated electron and hole are greatly reduced. The objective of this project is the design and fabrication of step-scheme (S-scheme) heterajunction photocatalyst, consisting of an oxidation photocatalyst and a reduction photocatalyst, which is utilized for photocatalytic H2 generation and CO2 reduction. This heterojunction photocatalyst can overcome the shortcoming of traditional II heterojunction photocatalyst and has greater oxidation and reduction ability. The main research work includes microstructure control of morphology, phase, surface and interface, transfer and separation of photogenerated electron and hole, and the mechanism of photocatalytic reactions. The photocatalytic H2-production and CO2-reduction performance will be obviously enhanced by constructing S-scheme heterojunction between oxidation and reduction photocatalysts. The influence of chemical composition, morphology, phase, particle size, preparation method, surface structure, chemical status and other aspects on photocatalytic activity of S-scheme heterojunction photocatalyst will be carefully discussed and investigated. The intrinsic composition-structure-performance relationship and synergistic effect between oxidation and reduction photocatalysts will be established. New design idea and preparation method for S-scheme photocatalyst will be proposed and developed. This project will provide some new insight into the design and fabrication of heterojunction photocatalysts.