Towards an understanding of the surface photocatalytic decomposition of H2O: Electronic structure and femtosecond electron dynamics

点击翻译按钮获取中文摘要

This project aims towards a fundamental understanding of the photostimulated decomposition of water adsorbed on ruthenium and Ru-oxide surfaces, which is of key relevance for development of renewable energy sources by conversion of water to hydrogen using sunlight. In collaboration with the groups in Leiden, Cambridge and London we will use femtosecond timeresolved spectroscopic techniques and theoretical modeling to investigate the dynamics and mechanism of this process. In particular, we will focus on the electronic structure and the charge transfer dynamics of both the bare surface and the water/substrate interface. Our goal is to identify the relevant energy levels that initiate the photocatalytic decomposition of water and characterize the excited lifetimes and the competing electron relaxation dynamics at the adsorbate-substrate interface. The complexity of the surface will be varied in a controlled and systematic way using of water adsorbed on a single crystal Ru(001) surface, on a fully oxygen-covered (1x1)O/Ru(001) surface and on thin Ru-oxide layers as well as co-adsorbed alkali atoms. As experimental techniques we will use ultraviolet photoelectron spectroscopy (UPS) and femtosecond time-resolved two-photoemission (2PPE), which allows to study both the energetics and the dynamics of the excited state.