Hydrogen in anatase TiO2

点击翻译按钮获取中文摘要

Since the discovery of photocatalytic splitting of water on titanium dioxide (TiO2) electrodes this semiconductor became an object of intensive research. In nature it occurs in three crystalline modifications: rutile, brookite, and anatase. Higher electron mobility, longer carrier lifetime, and exciton diffusion length make the latter the material of choice for a variety of applications starting from photovoltaic devices and ending with energy renewal and destruction of organic compounds in wastewater. A problem to be solved though is a low efficiency of photocatalysis since due to the wide band gap of TiO2 it harvests only a small fraction of the solar energy. A leap forward was recently achieved via engineering "black" hydrogenated anatase with a much narrower band gap. In spite of this breakthrough, understanding of hydrogen in anatase is limited. The proposed project aims to bridge this gap. Spectroscopic methods will be employed to get insight into the structural and electrical properties of hydrogen with an emphasis on interstitial species, hydrogen trapped at the oxygen vacancy, and hydrogen-acceptor complexes such as the Ti vacancy passivated by hydrogen.