一维CdSe@CdS-Cu异质结材料的构建及其光催化还原CO2的机理研究

发展高效、稳定的新型光催化剂将二氧化碳转化为可再生碳氢燃料和重要化学品，对于实现清洁能源的生产具有重要意义。目前，光催化转化二氧化碳的研究工作主要集中于催化剂的合成与调控，缺乏对光化学转换微观机制的充分认识。本项目以半导体CdSe@CdS核壳纳米棒为吸光材料，金属Cu为催化活性中心，通过晶种辅助外延生长策略精准构筑尺寸、形貌可控的一维CdSe@CdS-Cu（Cu：纳米晶、团簇、单原子）异质结材料，实现具有高活性和选择性的光催化二氧化碳还原。同时，发挥同步辐射谱学技术在材料原子尺度表征上的优势，利用同步辐射原位X射线吸收谱和原位红外光谱，探测光催化还原CO2反应状态下表面活性中心的原子和电子结构的动态演变规律和CO2还原反应路径，并结合飞秒瞬态吸收光谱对多电荷转移动力学的探测实验和光催化性能研究，建立更加系统、全面的材料结构与催化性能的内在关联，为新型高性能光催化剂的设计提供理论指导。

The development of efficient and stable photocatalysts converting carbon dioxide into renewable hydrocarbon fuels and important chemicals is of great significance for the realization of clean energy production. The current research work on photocatalytic conversion of carbon dioxide mainly focuses on the synthesis and regulation of catalysts, and lacks a sufficient understanding of the microscopic mechanism of photochemical conversion. In this project, semiconductor CdSe@CdS core-shell nanorods are adopted as light-absorbing materials, and metal Cu is used as the catalytically active center. A seed-assisted epitaxial growth strategy is used to accurately build a one-dimensional CdSe@CdS-Cu (Cu: nanocrystal, cluster, single atom) heterojunction materials to achieve photocatalytic carbon dioxide reduction with high activity and selectivity. At the same time, making full use of the advantages of synchrotron radiation spectroscopy in the atomic-scale characterization of materials, we intend to use synchrotron radiation in-situ X-ray absorption spectroscopy and in-situ infrared spectroscopy to detect the dynamics evolution of the atomic and electronic structure of the surface active center and the reaction pathway under the real photocatalytic reduction of carbon dioxide. Combined with femtosecond transient absorption spectroscopy experiments for multiple charge transfer kinetics and photocatalytic performance studies, we will have a better understanding on the relationship between structure and properties in photocatalytic systems, which can guide the rational design of new types of high-performance photocatalysts.