Hydrogen in anatase TiO2

自从二氧化钛（TiO2）电极上的水的光催化分裂被发现以来，这种半导体成为了深入研究的对象。在自然界中，它以三种晶体改性形式存在：金红石、蓝铜矿和锐钛矿。更高的电子迁移率、更长的载流子寿命和激子扩散长度使后者成为从光伏器件到废水中有机化合物的能量更新和破坏等各种应用的首选材料。然而，由于TiO2的带隙很宽，光催化的效率很低，这是一个有待解决的问题，因为它只能获得一小部分太阳能。最近通过工程“黑色”氢化锐钛矿实现了一个飞跃，具有更窄的带隙。尽管取得了这一突破，但对锐钛矿中氢的了解仍然有限。拟议的项目旨在弥合这一差距。光谱学方法将被用来深入了解氢的结构和电学性质，重点是间隙物质、被困在氧空位上的氢和氢受体配合物，如被氢钝化的钛空位。

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.