Hydrogen in anatase TiO2

自从发现在二氧化钛（TiO 2）电极上光催化分解水以来，这种半导体成为深入研究的对象。在自然界中，它以三种结晶形态存在：金红石、板钛矿和金红石。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开始到以能量更新和废水中有机化合物的破坏结束的各种应用的选择材料。然而，要解决的问题是低效率的光催化剂，因为由于TiO2的宽带隙，它仅收集太阳能的一小部分。最近，通过设计具有更窄带隙的“黑色”氢化物，实现了一个飞跃。尽管有了这一突破，但对氢的了解仍然有限。拟议的项目旨在弥合这一差距。光谱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，氢被困在氧空位，和氢受体复合物，如钛空位钝化氢。

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.