二维材料层下限域催化的光电化学分解水

窄带隙半导体与电催化剂的集成是制备高效稳定的光电化学分解水电极的重要策略。二维材料层下的限域催化剂通过改变催化活性位点的微环镜而提高催化活性，是一种新颖的高效催化剂。目前，国内外对二维材料层下限域催化的理论研究发展迅速，但是二维材料层下限域催化在光电化学分解水电极中的集成在实验上面临挑战。在本项目中，申请人拟首次将石墨烯层下限域催化应用到窄带隙半导体硅的光电化学分解水反应中，通过限域催化剂与硅的界面设计以及石墨烯限域层的缺陷设计，提出二维材料层下限域催化剂在光电极上的高效集成策略；并结合瞬态光谱技术和第一性原理计算深入分析二维材料层下限域催化在光电化学分解水中的作用机制，包括界面载流子传输、反应物和产物的吸脱附、反应势垒等。相关规律和结果可以推广到CO2还原等其它限域催化反应体系，对光电催化机理的探究以及催化材料性能的进一步提升具有重要意义。

The coupling of low-bandgap semiconductors with electrocatalyst is an important strategy to get stable and efficient photoelectrodes for photoelectrochemical (PEC) water splitting. Confined catalyst under two-dimensional cover (CCTC) has emerging as a novel potent catalyst in various important reactions due to its role in changing the micro-environment of the active sites. However, to date, the coupling of CCTC with semiconductors faces great challenges in experiments, although great progresses have been made on theoretical investigations. In this proposal, it is intended to modify graphene confined electrocatalyst on silicon photoelectrodes for PEC water splitting for the first time by the design of interfaces between silicon and the confined catalyst as well as the design of graphene defects, and give the general method for the coupling of CCTC with semiconductors. Most importantly, the applicant will give in-depth understandings of the CCTC in PEC water splitting including interfacial charge transfer, adsorption/desorption of the reactant/products, and the reaction barriers by combination of transient spectroscopy and first-principal calculations. The results can extend to other catalysis systems such as CO2 reduction and might inspire new designs for high-efficiency catalysts.